1.12 HDFFV-11310 implement JNI VL support for primitive types (#1856)

* HDFFV-11310 - implement VL read/write using List of Lists

* Fix function name typo

* Add JIRA issue

* Correct note to match change in code.

* HDFFV-11318 add VL references as byte arrays

* Fix unreleased allocations

* Fix format

19 files changed, 2710 insertions, 571 deletions

diff --git a/config/sanitizer/code-coverage.cmake b/config/sanitizer/code-coverage.cmake
index e71bfd7..3a99024 100644
--- a/config/sanitizer/code-coverage.cmake
+++ b/config/sanitizer/code-coverage.cmake
@@ -214,7 +214,7 @@ function(target_code_coverage TARGET_NAME)
     # Add code coverage instrumentation to the target's linker command
     if(CMAKE_C_COMPILER_ID MATCHES "[Cc]lang" OR CMAKE_CXX_COMPILER_ID MATCHES "[Cc]lang")
       target_compile_options(${TARGET_NAME} PRIVATE -fprofile-instr-generate
-                                                    -fcoverage-mapping)
+                                                    -fcoverage-mapping --coverage)
       set_property(
         TARGET ${TARGET_NAME}
         APPEND_STRING
@@ -225,7 +225,7 @@ function(target_code_coverage TARGET_NAME)
         PROPERTY LINK_FLAGS "-fcoverage-mapping ")
     elseif(CMAKE_C_COMPILER_ID MATCHES "GNU" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU")
       target_compile_options(${TARGET_NAME} PRIVATE -fprofile-arcs
-                                                    -ftest-coverage)
+                                                    -ftest-coverage --coverage)
       target_link_libraries(${TARGET_NAME} PRIVATE gcov)
     endif()
 
@@ -413,10 +413,10 @@ endfunction()
 # use `target_code_coverage`.
 function(add_code_coverage)
   if(CMAKE_C_COMPILER_ID MATCHES "[Cc]lang" OR CMAKE_CXX_COMPILER_ID MATCHES "[Cc]lang")
-    add_compile_options(-fprofile-instr-generate -fcoverage-mapping)
-    add_link_options(-fprofile-instr-generate -fcoverage-mapping)
+    add_compile_options(-fprofile-instr-generate -fcoverage-mapping --coverage)
+    add_link_options(-fprofile-instr-generate -fcoverage-mapping --coverage)
   elseif(CMAKE_C_COMPILER_ID MATCHES "GNU" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU")
-    add_compile_options(-fprofile-arcs -ftest-coverage)
+    add_compile_options(-fprofile-arcs -ftest-coverage --coverage)
     link_libraries(gcov)
   endif()
 endfunction()
diff --git a/java/src/hdf/hdf5lib/H5.java b/java/src/hdf/hdf5lib/H5.java
index 133cd2c..c2be6ca 100644
--- a/java/src/hdf/hdf5lib/H5.java
+++ b/java/src/hdf/hdf5lib/H5.java
@@ -1242,6 +1242,10 @@ public class H5 implements java.io.Serializable {
             log.trace("H5Aread_string type");
             status = H5Aread_string(attr_id, mem_type_id, (String[])obj);
         }
+        else if (H5.H5Tget_class(mem_type_id) == HDF5Constants.H5T_VLEN) {
+            log.trace("H5AreadVL type");
+            status = H5AreadVL(attr_id, mem_type_id, (Object[])obj);
+        }
         else {
             // Create a data buffer to hold the data into a Java Array
             HDFArray theArray = new HDFArray(obj);
@@ -1788,6 +1792,10 @@ public class H5 implements java.io.Serializable {
             log.trace("H5Dwrite_string type");
             status = H5Awrite_string(attr_id, mem_type_id, (String[])obj);
         }
+        else if (H5.H5Tget_class(mem_type_id) == HDF5Constants.H5T_VLEN) {
+            log.trace("H5AwriteVL type");
+            status = H5AwriteVL(attr_id, mem_type_id, (Object[])obj);
+        }
         else {
             HDFArray theArray = new HDFArray(obj);
             byte[] buf        = theArray.byteify();
@@ -2772,6 +2780,11 @@ public class H5 implements java.io.Serializable {
             status = H5Dread_string(dataset_id, mem_type_id, mem_space_id, file_space_id, xfer_plist_id,
                                     (String[])obj);
         }
+        else if (H5.H5Tget_class(mem_type_id) == HDF5Constants.H5T_VLEN) {
+            log.trace("H5DreadVL type");
+            status =
+                H5DreadVL(dataset_id, mem_type_id, mem_space_id, file_space_id, xfer_plist_id, (Object[])obj);
+        }
         else {
             // Create a data buffer to hold the data into a Java Array
             HDFArray theArray = new HDFArray(obj);
@@ -3450,6 +3463,11 @@ public class H5 implements java.io.Serializable {
             status = H5Dwrite_string(dataset_id, mem_type_id, mem_space_id, file_space_id, xfer_plist_id,
                                      (String[])obj);
         }
+        else if (H5.H5Tget_class(mem_type_id) == HDF5Constants.H5T_VLEN) {
+            log.trace("H5DwriteVL type");
+            status = H5DwriteVL(dataset_id, mem_type_id, mem_space_id, file_space_id, xfer_plist_id,
+                                (Object[])obj);
+        }
         else {
             HDFArray theArray = new HDFArray(obj);
             byte[] buf        = theArray.byteify();
@@ -9356,9 +9374,8 @@ public class H5 implements java.io.Serializable {
         byte[] buf        = theArray.emptyBytes();
 
         int status = H5Pget_fill_value(plist_id, type_id, buf);
-        if (status >= 0) {
+        if (status >= 0)
             obj = theArray.arrayify(buf);
-        }
 
         return status;
     }
@@ -11018,8 +11035,6 @@ public class H5 implements java.io.Serializable {
     public synchronized static native void H5Rdestroy(byte[] ref_ptr)
         throws HDF5LibraryException, NullPointerException, IllegalArgumentException;
 
-    // Info //
-
     /**
      * H5Rget_type retrieves the type of a reference.
      *
@@ -11076,8 +11091,6 @@ public class H5 implements java.io.Serializable {
     public synchronized static native byte[] H5Rcopy(byte[] src_ref_ptr)
         throws HDF5LibraryException, NullPointerException, IllegalArgumentException;
 
-    // Dereference //
-
     /**
      * H5Ropen_object opens that object and returns an identifier.
      * The object opened with this function should be closed when it is no longer needed
@@ -11224,8 +11237,6 @@ public class H5 implements java.io.Serializable {
     public synchronized static native int H5Rget_obj_type3(byte[] ref_ptr, long rapl_id)
         throws HDF5LibraryException, NullPointerException, IllegalArgumentException;
 
-    // Get name //
-
     /**
      * H5Rget_file_name retrieves the file name for the object, region or attribute reference pointed to.
      *
diff --git a/java/src/hdf/hdf5lib/HDF5Constants.java b/java/src/hdf/hdf5lib/HDF5Constants.java
index 1b85c1f..2f5ec91 100644
--- a/java/src/hdf/hdf5lib/HDF5Constants.java
+++ b/java/src/hdf/hdf5lib/HDF5Constants.java
@@ -16,7 +16,7 @@ package hdf.hdf5lib;
 import hdf.hdf5lib.structs.H5O_token_t;
 
 /**
- * /** This class contains C constants and enumerated types of HDF5 library. The
+ * This class contains C constants and enumerated types of HDF5 library. The
  * values of these constants are obtained from the library by calling J2C(int
  * jconstant), where jconstant is any of the private constants which start their
  * name with "JH5" need to be converted.
@@ -62,31 +62,62 @@ public class HDF5Constants {
     public static final int H5_ITER_NATIVE = H5_ITER_NATIVE();
     /** Common iteration orders, Number of iteration orders */
     public static final int H5_ITER_N = H5_ITER_N();
-    /** */
+    /** The version of the H5AC_cache_config_t in use */
     public static final int H5AC_CURR_CACHE_CONFIG_VERSION = H5AC_CURR_CACHE_CONFIG_VERSION();
-    /** */
+    /** The maximum length of the trace file path */
     public static final int H5AC_MAX_TRACE_FILE_NAME_LEN = H5AC_MAX_TRACE_FILE_NAME_LEN();
-    /** */
+    /**
+     *    When metadata_write_strategy is set to this value, only process
+     *    zero is allowed to write dirty metadata to disk.  All other
+     *    processes must retain dirty metadata until they are informed at
+     *    a sync point that the dirty metadata in question has been written
+     *    to disk.
+     */
     public static final int H5AC_METADATA_WRITE_STRATEGY_PROCESS_ZERO_ONLY =
         H5AC_METADATA_WRITE_STRATEGY_PROCESS_ZERO_ONLY();
-    /** */
+    /**
+     *    In the distributed metadata write strategy, process zero still makes
+     *    the decisions as to what entries should be flushed, but the actual
+     *    flushes are distributed across the processes in the computation to
+     *    the extent possible.
+     */
     public static final int H5AC_METADATA_WRITE_STRATEGY_DISTRIBUTED =
         H5AC_METADATA_WRITE_STRATEGY_DISTRIBUTED();
-    /** */
+    /** Don't attempt to increase the size of the cache automatically */
     public static final int H5C_incr_off = H5C_incr_off();
-    /** */
+    /**
+     *  Attempt to increase the size of the cache
+     *              whenever the average hit rate over the last epoch drops
+     *              below the value supplied in the lower_hr_threshold
+     *              field
+     */
     public static final int H5C_incr_threshold = H5C_incr_threshold();
-    /** */
+    /** Don't perform flash increases in the size of the cache */
     public static final int H5C_flash_incr_off = H5C_flash_incr_off();
-    /** */
+    /** increase the current maximum cache size by x * flash_multiple less any free space in the cache */
     public static final int H5C_flash_incr_add_space = H5C_flash_incr_add_space();
-    /** */
+    /** Don't attempt to decrease the size of the cache automatically */
     public static final int H5C_decr_off = H5C_decr_off();
-    /** */
+    /**
+     *  Attempt to decrease the size of the cache
+     *              whenever the average hit rate over the last epoch rises
+     *              above the value supplied in the upper_hr_threshold
+     *              field
+     */
     public static final int H5C_decr_threshold = H5C_decr_threshold();
-    /** */
+    /**
+     *  At the end of each epoch, search the cache for
+     *              entries that have not been accessed for at least the number
+     *              of epochs specified in the epochs_before_eviction field, and
+     *              evict these entries
+     */
     public static final int H5C_decr_age_out = H5C_decr_age_out();
-    /** */
+    /**
+     *  Same as age_out, but we only
+     *              attempt to reduce the cache size when the hit rate observed
+     *              over the last epoch exceeds the value provided in the
+     *              upper_hr_threshold field
+     */
     public static final int H5C_decr_age_out_with_threshold = H5C_decr_age_out_with_threshold();
     /** */
     public static final int H5D_CHUNK_IDX_BTREE = H5D_CHUNK_IDX_BTREE();
@@ -910,11 +941,11 @@ public class HDF5Constants {
     /** */
     public static final int H5R_MAXTYPE = H5R_MAXTYPE();
     /** */
-    public static final int H5R_REF_BUF_SIZE = H5R_REF_BUF_SIZE();
+    public static final int H5R_DSET_REG_REF_BUF_SIZE = H5R_DSET_REG_REF_BUF_SIZE();
     /** */
     public static final int H5R_OBJ_REF_BUF_SIZE = H5R_OBJ_REF_BUF_SIZE();
     /** */
-    public static final int H5R_DSET_REG_REF_BUF_SIZE = H5R_DSET_REG_REF_BUF_SIZE();
+    public static final int H5R_REF_BUF_SIZE = H5R_REF_BUF_SIZE();
     /** */
     public static final int H5R_OBJECT = H5R_OBJECT();
     /** */
@@ -2393,11 +2424,11 @@ public class HDF5Constants {
 
     private static native final int H5R_MAXTYPE();
 
-    private static native final int H5R_REF_BUF_SIZE();
+    private static native final int H5R_DSET_REG_REF_BUF_SIZE();
 
     private static native final int H5R_OBJ_REF_BUF_SIZE();
 
-    private static native final int H5R_DSET_REG_REF_BUF_SIZE();
+    private static native final int H5R_REF_BUF_SIZE();
 
     private static native final int H5R_OBJECT();
 
diff --git a/java/src/jni/h5aImp.c b/java/src/jni/h5aImp.c
index 6bf86d0..32bae07 100644
--- a/java/src/jni/h5aImp.c
+++ b/java/src/jni/h5aImp.c
@@ -56,7 +56,7 @@ static herr_t H5A_iterate_cb(hid_t g_id, const char *name, const H5A_info_t *inf
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Acreate
+ * Method:    _H5Acreate
  * Signature: (JLjava/lang/String;JJJ)J
  */
 JNIEXPORT jlong JNICALL
@@ -86,7 +86,7 @@ done:
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Aopen_name
+ * Method:    _H5Aopen_name
  * Signature: (JLjava/lang/String;)J
  */
 JNIEXPORT jlong JNICALL
@@ -124,7 +124,7 @@ done:
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Aopen_idx
+ * Method:    _H5Aopen_idx
  * Signature: (JI)J
  */
 JNIEXPORT jlong JNICALL
@@ -158,7 +158,10 @@ Java_hdf_hdf5lib_H5_H5Aread(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_t
 {
     jboolean readBufIsCopy;
     jbyte *  readBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -166,18 +169,20 @@ Java_hdf_hdf5lib_H5_H5Aread(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_t
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Aread: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: variable length type not supported");
-
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
+    if (vl_data_class) {
+        /* Get size of data array */
+        if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+            H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+        }
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: variable length type not supported");
+        dims[0] = (hsize_t)n;
+        if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
 
     if (isCriticalPinning) {
         PIN_BYTE_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
@@ -187,11 +192,17 @@ Java_hdf_hdf5lib_H5_H5Aread(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_t
         PIN_BYTE_ARRAY(ENVONLY, buf, readBuf, &readBufIsCopy, "H5Aread: read buffer not pinned");
     }
 
-    if ((status = H5Aread((hid_t)attr_id, (hid_t)mem_type_id, readBuf)) < 0)
+    if ((status = H5Aread((hid_t)attr_id, (hid_t)mem_type_id, (void *)readBuf)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class) {
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, readBuf);
+            if (sid >= 0)
+                H5Sclose(sid);
+        }
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -214,7 +225,10 @@ Java_hdf_hdf5lib_H5_H5Awrite(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_
 {
     jboolean writeBufIsCopy;
     jbyte *  writeBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -222,18 +236,18 @@ Java_hdf_hdf5lib_H5_H5Awrite(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Awrite: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite: variable length type not supported");
+    /* Get size of data array */
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    dims[0] = (hsize_t)n;
+    if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite: variable length type not supported");
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
 
     if (isCriticalPinning) {
         PIN_BYTE_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
@@ -248,6 +262,9 @@ Java_hdf_hdf5lib_H5_H5Awrite(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -270,7 +287,10 @@ Java_hdf_hdf5lib_H5_H5Aread_1short(JNIEnv *env, jclass clss, jlong attr_id, jlon
 {
     jboolean readBufIsCopy;
     jshort * readBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -278,18 +298,20 @@ Java_hdf_hdf5lib_H5_H5Aread_1short(JNIEnv *env, jclass clss, jlong attr_id, jlon
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Aread_short: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_short: variable length type not supported");
-
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
+    if (vl_data_class) {
+        /* Get size of data array */
+        if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+            H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+        }
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_short: variable length type not supported");
+        dims[0] = (hsize_t)n;
+        if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
 
     if (isCriticalPinning) {
         PIN_SHORT_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
@@ -304,6 +326,12 @@ Java_hdf_hdf5lib_H5_H5Aread_1short(JNIEnv *env, jclass clss, jlong attr_id, jlon
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class) {
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, readBuf);
+            if (sid >= 0)
+                H5Sclose(sid);
+        }
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -326,7 +354,10 @@ Java_hdf_hdf5lib_H5_H5Awrite_1short(JNIEnv *env, jclass clss, jlong attr_id, jlo
 {
     jboolean writeBufIsCopy;
     jshort * writeBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -334,18 +365,18 @@ Java_hdf_hdf5lib_H5_H5Awrite_1short(JNIEnv *env, jclass clss, jlong attr_id, jlo
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Awrite_short: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_short: variable length type not supported");
+    /* Get size of data array */
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    dims[0] = (hsize_t)n;
+    if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_short: variable length type not supported");
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
 
     if (isCriticalPinning) {
         PIN_SHORT_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
@@ -360,6 +391,9 @@ Java_hdf_hdf5lib_H5_H5Awrite_1short(JNIEnv *env, jclass clss, jlong attr_id, jlo
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -381,27 +415,32 @@ Java_hdf_hdf5lib_H5_H5Aread_1int(JNIEnv *env, jclass clss, jlong attr_id, jlong
                                  jboolean isCriticalPinning)
 {
     jboolean readBufIsCopy;
-    htri_t   data_class;
     jint *   readBuf = NULL;
-    herr_t   status  = FAIL;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (buf == NULL)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Aread_int: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_int: variable length type not supported");
-
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
+    if (vl_data_class) {
+        /* Get size of data array */
+        if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+            H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+        }
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_int: variable length type not supported");
+        dims[0] = (hsize_t)n;
+        if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
 
     if (isCriticalPinning) {
         PIN_INT_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
@@ -416,6 +455,12 @@ Java_hdf_hdf5lib_H5_H5Aread_1int(JNIEnv *env, jclass clss, jlong attr_id, jlong
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class) {
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, readBuf);
+            if (sid >= 0)
+                H5Sclose(sid);
+        }
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -438,7 +483,10 @@ Java_hdf_hdf5lib_H5_H5Awrite_1int(JNIEnv *env, jclass clss, jlong attr_id, jlong
 {
     jboolean writeBufIsCopy;
     jint *   writeBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -446,18 +494,18 @@ Java_hdf_hdf5lib_H5_H5Awrite_1int(JNIEnv *env, jclass clss, jlong attr_id, jlong
     if (buf == NULL)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Awrite_int: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_int: variable length type not supported");
+    /* Get size of data array */
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    dims[0] = (hsize_t)n;
+    if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_int: variable length type not supported");
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
 
     if (isCriticalPinning) {
         PIN_INT_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
@@ -472,6 +520,9 @@ Java_hdf_hdf5lib_H5_H5Awrite_1int(JNIEnv *env, jclass clss, jlong attr_id, jlong
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -494,7 +545,10 @@ Java_hdf_hdf5lib_H5_H5Aread_1long(JNIEnv *env, jclass clss, jlong attr_id, jlong
 {
     jboolean readBufIsCopy;
     jlong *  readBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -502,18 +556,20 @@ Java_hdf_hdf5lib_H5_H5Aread_1long(JNIEnv *env, jclass clss, jlong attr_id, jlong
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Aread_long: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_long: variable length type not supported");
-
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
+    if (vl_data_class) {
+        /* Get size of data array */
+        if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+            H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+        }
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_long: variable length type not supported");
+        dims[0] = (hsize_t)n;
+        if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
 
     if (isCriticalPinning) {
         PIN_LONG_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
@@ -528,6 +584,12 @@ Java_hdf_hdf5lib_H5_H5Aread_1long(JNIEnv *env, jclass clss, jlong attr_id, jlong
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class) {
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, readBuf);
+            if (sid >= 0)
+                H5Sclose(sid);
+        }
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -550,7 +612,10 @@ Java_hdf_hdf5lib_H5_H5Awrite_1long(JNIEnv *env, jclass clss, jlong attr_id, jlon
 {
     jboolean writeBufIsCopy;
     jlong *  writeBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -558,18 +623,18 @@ Java_hdf_hdf5lib_H5_H5Awrite_1long(JNIEnv *env, jclass clss, jlong attr_id, jlon
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Awrite_long: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_long: variable length type not supported");
+    /* Get size of data array */
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    dims[0] = (hsize_t)n;
+    if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_long: variable length type not supported");
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
 
     if (isCriticalPinning) {
         PIN_LONG_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
@@ -584,6 +649,9 @@ Java_hdf_hdf5lib_H5_H5Awrite_1long(JNIEnv *env, jclass clss, jlong attr_id, jlon
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -606,7 +674,10 @@ Java_hdf_hdf5lib_H5_H5Aread_1float(JNIEnv *env, jclass clss, jlong attr_id, jlon
 {
     jboolean readBufIsCopy;
     jfloat * readBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -614,18 +685,20 @@ Java_hdf_hdf5lib_H5_H5Aread_1float(JNIEnv *env, jclass clss, jlong attr_id, jlon
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Aread_float: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_float: variable length type not supported");
-
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
+    if (vl_data_class) {
+        /* Get size of data array */
+        if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+            H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+        }
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_float: variable length type not supported");
+        dims[0] = (hsize_t)n;
+        if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
 
     if (isCriticalPinning) {
         PIN_FLOAT_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
@@ -640,6 +713,12 @@ Java_hdf_hdf5lib_H5_H5Aread_1float(JNIEnv *env, jclass clss, jlong attr_id, jlon
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class) {
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, readBuf);
+            if (sid >= 0)
+                H5Sclose(sid);
+        }
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -662,7 +741,10 @@ Java_hdf_hdf5lib_H5_H5Awrite_1float(JNIEnv *env, jclass clss, jlong attr_id, jlo
 {
     jboolean writeBufIsCopy;
     jfloat * writeBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -670,18 +752,18 @@ Java_hdf_hdf5lib_H5_H5Awrite_1float(JNIEnv *env, jclass clss, jlong attr_id, jlo
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Awrite_float: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_float: variable length type not supported");
+    /* Get size of data array */
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    dims[0] = (hsize_t)n;
+    if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_float: variable length type not supported");
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
 
     if (isCriticalPinning) {
         PIN_FLOAT_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
@@ -696,6 +778,9 @@ Java_hdf_hdf5lib_H5_H5Awrite_1float(JNIEnv *env, jclass clss, jlong attr_id, jlo
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -718,7 +803,10 @@ Java_hdf_hdf5lib_H5_H5Aread_1double(JNIEnv *env, jclass clss, jlong attr_id, jlo
 {
     jboolean readBufIsCopy;
     jdouble *readBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -726,18 +814,20 @@ Java_hdf_hdf5lib_H5_H5Aread_1double(JNIEnv *env, jclass clss, jlong attr_id, jlo
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Aread_double: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_double: variable length type not supported");
-
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
+    if (vl_data_class) {
+        /* Get size of data array */
+        if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+            H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+        }
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread_double: variable length type not supported");
+        dims[0] = (hsize_t)n;
+        if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
 
     if (isCriticalPinning) {
         PIN_DOUBLE_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
@@ -752,6 +842,12 @@ Java_hdf_hdf5lib_H5_H5Aread_1double(JNIEnv *env, jclass clss, jlong attr_id, jlo
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class) {
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, readBuf);
+            if (sid >= 0)
+                H5Sclose(sid);
+        }
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -774,7 +870,10 @@ Java_hdf_hdf5lib_H5_H5Awrite_1double(JNIEnv *env, jclass clss, jlong attr_id, jl
 {
     jboolean writeBufIsCopy;
     jdouble *writeBuf = NULL;
-    htri_t   data_class;
+    hsize_t  dims[H5S_MAX_RANK];
+    hid_t    sid = H5I_INVALID_HID;
+    jsize    n;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -782,18 +881,17 @@ Java_hdf_hdf5lib_H5_H5Awrite_1double(JNIEnv *env, jclass clss, jlong attr_id, jl
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Awrite_double: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_double: variable length type not supported");
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_double: buf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    dims[0] = (hsize_t)n;
+    if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Awrite_double: variable length type not supported");
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
 
     if (isCriticalPinning) {
         PIN_DOUBLE_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
@@ -808,6 +906,9 @@ Java_hdf_hdf5lib_H5_H5Awrite_1double(JNIEnv *env, jclass clss, jlong attr_id, jl
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -958,12 +1059,456 @@ done:
 /*
  * Class:     hdf_hdf5lib_H5
  * Method:    H5AreadVL
- * Signature: (JJ[Ljava/lang/String;)I
+ * Signature: (JJ[java/util/ArrayList;)I
  */
 JNIEXPORT jint JNICALL
 Java_hdf_hdf5lib_H5_H5AreadVL(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_type_id, jobjectArray buf)
 {
     H5T_class_t type_class;
+    hsize_t     dims[H5S_MAX_RANK];
+    hid_t       sid = H5I_INVALID_HID;
+    jsize       n;
+    htri_t      vl_data_class;
+    herr_t      status = FAIL;
+    jboolean    readBufIsCopy;
+    jbyteArray *readBuf = NULL;
+
+    UNUSED(clss);
+
+    if (NULL == buf)
+        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5AreadVL: read buffer is NULL");
+
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+
+    if (vl_data_class) {
+        /* Get size of data array */
+        if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+            H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+        }
+
+        dims[0] = (hsize_t)n;
+        if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
+
+    if ((type_class = H5Tget_class((hid_t)mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+    if (type_class == H5T_VLEN) {
+        size_t      typeSize;
+        hid_t       memb = H5I_INVALID_HID;
+        H5T_class_t vlClass;
+        size_t      vlSize;
+        void *      rawBuf = NULL;
+        jobject *   jList  = NULL;
+
+        size_t i, j, x;
+        char * cp_vp = NULL;
+
+        if (!(typeSize = H5Tget_size(mem_type_id)))
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        if (!(memb = H5Tget_super(mem_type_id)))
+            H5_LIBRARY_ERROR(ENVONLY);
+        if ((vlClass = H5Tget_class((hid_t)memb)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+        if (!(vlSize = H5Tget_size(memb)))
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        if (NULL == (rawBuf = HDcalloc((size_t)n, typeSize)))
+            H5_OUT_OF_MEMORY_ERROR(ENVONLY, "H5AreadVL: failed to allocate raw VL read buffer");
+
+        if ((status = H5Aread((hid_t)attr_id, (hid_t)mem_type_id, (void *)rawBuf)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        /* Cache class types */
+        jclass cBool   = ENVPTR->FindClass(ENVONLY, "java/lang/Boolean");
+        jclass cByte   = ENVPTR->FindClass(ENVONLY, "java/lang/Byte");
+        jclass cShort  = ENVPTR->FindClass(ENVONLY, "java/lang/Short");
+        jclass cInt    = ENVPTR->FindClass(ENVONLY, "java/lang/Integer");
+        jclass cLong   = ENVPTR->FindClass(ENVONLY, "java/lang/Long");
+        jclass cFloat  = ENVPTR->FindClass(ENVONLY, "java/lang/Float");
+        jclass cDouble = ENVPTR->FindClass(ENVONLY, "java/lang/Double");
+
+        jmethodID boolValueMid =
+            ENVPTR->GetStaticMethodID(ENVONLY, cBool, "valueOf", "(Z)Ljava/lang/Boolean;");
+        jmethodID byteValueMid = ENVPTR->GetStaticMethodID(ENVONLY, cByte, "valueOf", "(B)Ljava/lang/Byte;");
+        jmethodID shortValueMid =
+            ENVPTR->GetStaticMethodID(ENVONLY, cShort, "valueOf", "(S)Ljava/lang/Short;");
+        jmethodID intValueMid = ENVPTR->GetStaticMethodID(ENVONLY, cInt, "valueOf", "(I)Ljava/lang/Integer;");
+        jmethodID longValueMid = ENVPTR->GetStaticMethodID(ENVONLY, cLong, "valueOf", "(J)Ljava/lang/Long;");
+        jmethodID floatValueMid =
+            ENVPTR->GetStaticMethodID(ENVONLY, cFloat, "valueOf", "(F)Ljava/lang/Float;");
+        jmethodID doubleValueMid =
+            ENVPTR->GetStaticMethodID(ENVONLY, cDouble, "valueOf", "(D)Ljava/lang/Double;");
+
+        // retrieve the java.util.List interface class
+        jclass    cList     = ENVPTR->FindClass(ENVONLY, "java/util/List");
+        jmethodID addMethod = ENVPTR->GetMethodID(ENVONLY, cList, "add", "(Ljava/lang/Object;)Z");
+
+        /* Convert each element to a list */
+        for (i = 0; i < (size_t)n; i++) {
+            // The list we're going to return:
+            if (NULL == (jList = ENVPTR->GetObjectArrayElement(ENVONLY, (jobjectArray)buf, (jsize)i)))
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+            cp_vp = (char *)rawBuf + i * typeSize;
+            /* Get the number of sequence elements */
+            jsize nelmts = ((hvl_t *)cp_vp)->len;
+
+            jobject jobj = NULL;
+            for (j = 0; j < nelmts; j++) {
+                switch (vlClass) {
+                    /* case H5T_BOOL: {
+                        jboolean boolValue;
+                        for (x = 0; x < (int)vlSize; x++) {
+                            ((char *)&boolValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j*vlSize+x];
+                        }
+
+                        jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cBool, boolValueMid, boolValue);
+                        CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                        break;
+                    } */
+                    case H5T_INTEGER: {
+                        switch (vlSize) {
+                            case sizeof(jbyte): {
+                                jbyte byteValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&byteValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj =
+                                    ENVPTR->CallStaticObjectMethod(ENVONLY, cByte, byteValueMid, byteValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                            case sizeof(jshort): {
+                                jshort shortValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&shortValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cShort, shortValueMid,
+                                                                      shortValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                            case sizeof(jint): {
+                                jint intValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&intValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cInt, intValueMid, intValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                            case sizeof(jlong): {
+                                jlong longValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&longValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj =
+                                    ENVPTR->CallStaticObjectMethod(ENVONLY, cLong, longValueMid, longValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case H5T_FLOAT: {
+                        switch (vlSize) {
+                            case sizeof(jfloat): {
+                                jfloat floatValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&floatValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cFloat, floatValueMid,
+                                                                      floatValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                            case sizeof(jdouble): {
+                                jdouble doubleValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&doubleValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cDouble, doubleValueMid,
+                                                                      doubleValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case H5T_REFERENCE: {
+                        jboolean bb;
+                        jbyte *  barray = NULL;
+                        if (NULL == (jobj = ENVPTR->NewByteArray(ENVONLY, vlSize)))
+                            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+                        PIN_BYTE_ARRAY(ENVONLY, (jbyteArray)jobj, barray, &bb,
+                                       "readVL reference: byte array not pinned");
+
+                        for (x = 0; x < (int)vlSize; x++) {
+                            barray[x] = ((jbyte *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                        }
+                        if (barray)
+                            UNPIN_BYTE_ARRAY(ENVONLY, (jbyteArray)jobj, barray, jobj ? 0 : JNI_ABORT);
+                        break;
+                    }
+                    default:
+                        H5_UNIMPLEMENTED(ENVONLY, "H5AreadVL: invalid class type");
+                        break;
+                }
+
+                // Add it to the list
+                ENVPTR->CallBooleanMethod(ENVONLY, jList, addMethod, jobj);
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+            }
+        } /* end for */
+
+        if (rawBuf)
+            HDfree(rawBuf);
+    }
+    else {
+        if ((status = H5Aread((hid_t)attr_id, (hid_t)mem_type_id, (void *)readBuf)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
+
+done:
+    if (readBuf) {
+        if ((status >= 0) && vl_data_class) {
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, readBuf);
+            if (sid >= 0)
+                H5Sclose(sid);
+        }
+
+        UNPIN_BYTE_ARRAY(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
+    }
+
+    return (jint)status;
+} /* end Java_hdf_hdf5lib_H5_H5AreadVL */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5AwriteVL
+ * Signature: (JJ[java/util/ArrayList;)I
+ */
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_H5_H5AwriteVL(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_type_id, jobjectArray buf)
+{
+    H5T_class_t type_class;
+    hsize_t     dims[H5S_MAX_RANK];
+    hid_t       sid = H5I_INVALID_HID;
+    jsize       n;
+    htri_t      vl_data_class;
+    herr_t      status = FAIL;
+    jboolean    writeBufIsCopy;
+    jbyteArray *writeBuf = NULL;
+
+    UNUSED(clss);
+
+    if (NULL == buf)
+        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5AwriteVL: write buffer is NULL");
+
+    /* Get size of data array */
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5AwriteVL: readBuf length < 0");
+    }
+
+    dims[0] = (hsize_t)n;
+    if ((sid = H5Screate_simple(1, dims, NULL)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+
+    if ((type_class = H5Tget_class((hid_t)mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+    if (type_class == H5T_VLEN) {
+        size_t      typeSize;
+        hid_t       memb = H5I_INVALID_HID;
+        H5T_class_t vlClass;
+        size_t      vlSize;
+        void *      rawBuf = NULL;
+        jobject *   jList  = NULL;
+
+        size_t i, j, x;
+        char * cp_vp = NULL;
+
+        if (!(typeSize = H5Tget_size(mem_type_id)))
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        if (!(memb = H5Tget_super(mem_type_id)))
+            H5_LIBRARY_ERROR(ENVONLY);
+        if ((vlClass = H5Tget_class((hid_t)memb)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+        if (!(vlSize = H5Tget_size(memb)))
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        if (NULL == (rawBuf = HDcalloc((size_t)n, typeSize)))
+            H5_OUT_OF_MEMORY_ERROR(ENVONLY, "H5AwriteVL: failed to allocate raw VL write buffer");
+
+        /* Cache class types */
+        jclass cBool   = ENVPTR->FindClass(ENVONLY, "java/lang/Boolean");
+        jclass cByte   = ENVPTR->FindClass(ENVONLY, "java/lang/Byte");
+        jclass cShort  = ENVPTR->FindClass(ENVONLY, "java/lang/Short");
+        jclass cInt    = ENVPTR->FindClass(ENVONLY, "java/lang/Integer");
+        jclass cLong   = ENVPTR->FindClass(ENVONLY, "java/lang/Long");
+        jclass cFloat  = ENVPTR->FindClass(ENVONLY, "java/lang/Float");
+        jclass cDouble = ENVPTR->FindClass(ENVONLY, "java/lang/Double");
+
+        jmethodID boolValueMid   = ENVPTR->GetMethodID(ENVONLY, cBool, "booleanValue", "()Z");
+        jmethodID byteValueMid   = ENVPTR->GetMethodID(ENVONLY, cByte, "byteValue", "()B");
+        jmethodID shortValueMid  = ENVPTR->GetMethodID(ENVONLY, cShort, "shortValue", "()S");
+        jmethodID intValueMid    = ENVPTR->GetMethodID(ENVONLY, cInt, "intValue", "()I");
+        jmethodID longValueMid   = ENVPTR->GetMethodID(ENVONLY, cLong, "longValue", "()J");
+        jmethodID floatValueMid  = ENVPTR->GetMethodID(ENVONLY, cFloat, "floatValue", "()F");
+        jmethodID doubleValueMid = ENVPTR->GetMethodID(ENVONLY, cDouble, "doubleValue", "()D");
+
+        /* Convert each list to a vlen element */
+        for (i = 0; i < (size_t)n; i++) {
+            if (NULL == (jList = ENVPTR->GetObjectArrayElement(ENVONLY, (jobjectArray)buf, (jsize)i)))
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+            // retrieve the java.util.List interface class
+            jclass cList = ENVPTR->FindClass(ENVONLY, "java/util/List");
+
+            // retrieve the toArray method and invoke it
+            jmethodID mToArray = ENVPTR->GetMethodID(ENVONLY, cList, "toArray", "()[Ljava/lang/Object;");
+            if (mToArray == NULL)
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+            jobjectArray array   = (jobjectArray)ENVPTR->CallObjectMethod(ENVONLY, jList, mToArray);
+            jsize        jnelmts = ENVPTR->GetArrayLength(ENVONLY, array);
+
+            cp_vp                 = (char *)rawBuf + i * typeSize;
+            ((hvl_t *)cp_vp)->len = jnelmts;
+
+            if (NULL == (((hvl_t *)cp_vp)->p = HDmalloc(jnelmts * vlSize)))
+                H5_OUT_OF_MEMORY_ERROR(ENVONLY, "H5AwriteVL: failed to allocate vlen ptr buffer");
+
+            jobject jobj = NULL;
+            for (j = 0; j < (int)jnelmts; j++) {
+                if (NULL == (jobj = ENVPTR->GetObjectArrayElement(ENVONLY, (jobjectArray)array, (jsize)j)))
+                    CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+                switch (vlClass) {
+                    /* case H5T_BOOL: {
+                            jboolean boolValue = ENVPTR->CallBooleanMethod(ENVONLY, jobj, boolValueMid);
+                            for (x = 0; x < (int)vlSize; x++) {
+                                ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&boolValue)[x];
+                            }
+                            break;
+                    } */
+                    case H5T_INTEGER: {
+                        switch (vlSize) {
+                            case sizeof(jbyte): {
+                                jbyte byteValue = ENVPTR->CallByteMethod(ENVONLY, jobj, byteValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&byteValue)[x];
+                                }
+                                break;
+                            }
+                            case sizeof(jshort): {
+                                jshort shortValue = ENVPTR->CallShortMethod(ENVONLY, jobj, shortValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&shortValue)[x];
+                                }
+                                break;
+                            }
+                            case sizeof(jint): {
+                                jint intValue = ENVPTR->CallIntMethod(ENVONLY, jobj, intValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&intValue)[x];
+                                }
+                                break;
+                            }
+                            case sizeof(jlong): {
+                                jlong longValue = ENVPTR->CallLongMethod(ENVONLY, jobj, longValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&longValue)[x];
+                                }
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case H5T_FLOAT: {
+                        switch (vlSize) {
+                            case sizeof(jfloat): {
+                                jfloat floatValue = ENVPTR->CallFloatMethod(ENVONLY, jobj, floatValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&floatValue)[x];
+                                }
+                                break;
+                            }
+                            case sizeof(jdouble): {
+                                jdouble doubleValue = ENVPTR->CallDoubleMethod(ENVONLY, jobj, doubleValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&doubleValue)[x];
+                                }
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case H5T_REFERENCE: {
+                        jbyte *barray = (jbyte *)ENVPTR->GetByteArrayElements(ENVONLY, jobj, 0);
+                        for (x = 0; x < (int)vlSize; x++) {
+                            ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)barray)[x];
+                        }
+                        ENVPTR->ReleaseByteArrayElements(ENVONLY, jobj, barray, 0);
+                        break;
+                    }
+                    default:
+                        H5_UNIMPLEMENTED(ENVONLY, "H5AwriteVL: invalid class type");
+                        break;
+                }
+                ENVPTR->DeleteLocalRef(ENVONLY, jobj);
+            }
+            ENVPTR->DeleteLocalRef(ENVONLY, jList);
+        } /* end for (i = 0; i < n; i++) */
+
+        if ((status = H5Awrite((hid_t)attr_id, (hid_t)mem_type_id, rawBuf)) < 0)
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+        if (rawBuf)
+            HDfree(rawBuf);
+    }
+    else {
+        PIN_BYTE_ARRAY(ENVONLY, buf, writeBuf, &writeBufIsCopy, "H5AwriteVL: write buffer not pinned");
+        if ((status = H5Awrite((hid_t)attr_id, (hid_t)mem_type_id, writeBuf)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
+
+done:
+    if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(attr_id, sid, H5P_DEFAULT, writeBuf);
+
+        if (type_class != H5T_VLEN)
+            UNPIN_BYTE_ARRAY(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
+    }
+
+    return (jint)status;
+} /* end Java_hdf_hdf5lib_H5_H5AwriteVL */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5Aread_VLStrings
+ * Signature: (JJ[Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_H5_H5Aread_1VLStrings(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_type_id,
+                                       jobjectArray buf)
+{
+    H5T_class_t type_class;
     htri_t      isStr      = 0;
     htri_t      isVlenStr  = 0;
     htri_t      isComplex  = 0;
@@ -974,7 +1519,7 @@ Java_hdf_hdf5lib_H5_H5AreadVL(JNIEnv *env, jclass clss, jlong attr_id, jlong mem
     UNUSED(clss);
 
     if (NULL == buf)
-        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5AreadVL: read buffer is NULL");
+        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Aread_VLStrings: read buffer is NULL");
 
     if ((isStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
@@ -1024,7 +1569,7 @@ done:
         H5Tclose(nested_tid);
 
     return (jint)status;
-} /* end Java_hdf_hdf5lib_H5_H5Aread_1VL */
+} /* end Java_hdf_hdf5lib_H5_H5Aread_1VLStrings */
 
 /*
  * Helper method to read in a buffer of variable-length strings from an HDF5
@@ -1160,11 +1705,12 @@ done:
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5AwriteVL
+ * Method:    H5Awrite_VLStrings
  * Signature: (JJ[Ljava/lang/String;)I
  */
 JNIEXPORT jint JNICALL
-Java_hdf_hdf5lib_H5_H5AwriteVL(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_type_id, jobjectArray buf)
+Java_hdf_hdf5lib_H5_H5Awrite_1VLStrings(JNIEnv *env, jclass clss, jlong attr_id, jlong mem_type_id,
+                                        jobjectArray buf)
 {
     H5T_class_t type_class;
     htri_t      isStr      = 0;
@@ -1177,7 +1723,7 @@ Java_hdf_hdf5lib_H5_H5AwriteVL(JNIEnv *env, jclass clss, jlong attr_id, jlong me
     UNUSED(clss);
 
     if (NULL == buf)
-        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5AwriteVL: write buffer is NULL");
+        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Awrite_VLStrings: write buffer is NULL");
 
     if ((isStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
@@ -1227,7 +1773,7 @@ done:
         H5Tclose(nested_tid);
 
     return (jint)status;
-} /* end Java_hdf_hdf5lib_H5_H5Awrite_1VL */
+} /* end Java_hdf_hdf5lib_H5_H5Awrite_1VLStrings */
 
 /*
  * Helper method to convert an array of Java strings into a buffer of C-strings.
@@ -1273,7 +1819,7 @@ H5AwriteVL_str(JNIEnv *env, hid_t aid, hid_t tid, jobjectArray buf)
         if (NULL == (writeBuf[i] = (char *)HDmalloc((size_t)length + 1)))
             H5_OUT_OF_MEMORY_ERROR(ENVONLY, "H5AwriteVL_str: failed to allocate string buffer");
 
-        HDstrncpy(writeBuf[i], utf8, (size_t)length);
+        HDstrncpy(writeBuf[i], utf8, (size_t)length + 1);
         writeBuf[i][length] = '\0';
 
         UNPIN_JAVA_STRING(ENVONLY, obj, utf8);
@@ -1297,8 +1843,8 @@ done:
         HDfree(writeBuf);
     }
 
-    return (jint)status;
-}
+    return status;
+} /* end H5AwriteVL_str */
 
 /*
  * Helper method to convert an array of Java strings into a buffer of
@@ -1385,7 +1931,7 @@ done:
         H5Sclose(sid);
 
     return status;
-} /* end H5AwriteVL_str */
+} /* end H5AwriteVL_asstr */
 
 /*
  * Class:     hdf_hdf5lib_H5
diff --git a/java/src/jni/h5aImp.h b/java/src/jni/h5aImp.h
index aee0e40..094f990 100644
--- a/java/src/jni/h5aImp.h
+++ b/java/src/jni/h5aImp.h
@@ -22,7 +22,7 @@ extern "C" {
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Acreate
+ * Method:    _H5Acreate
  * Signature: (JLjava/lang/String;JJJ)J
  */
 JNIEXPORT jlong JNICALL Java_hdf_hdf5lib_H5__1H5Acreate(JNIEnv *, jclass, jlong, jstring, jlong, jlong,
@@ -30,14 +30,14 @@ JNIEXPORT jlong JNICALL Java_hdf_hdf5lib_H5__1H5Acreate(JNIEnv *, jclass, jlong,
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Aopen_name
+ * Method:    _H5Aopen_name
  * Signature: (JLjava/lang/String;)J
  */
 JNIEXPORT jlong JNICALL Java_hdf_hdf5lib_H5__1H5Aopen_1name(JNIEnv *, jclass, jlong, jstring);
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Aopen_idx
+ * Method:    _H5Aopen_idx
  * Signature: (JI)J
  */
 JNIEXPORT jlong JNICALL Java_hdf_hdf5lib_H5__1H5Aopen_1idx(JNIEnv *, jclass, jlong, jint);
@@ -137,14 +137,14 @@ JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5Awrite_1double(JNIEnv *, jclass, jl
 /*
  * Class:     hdf_hdf5lib_H5
  * Method:    H5AreadVL
- * Signature: (JJ[Ljava/lang/String;)I
+ * Signature: (JJ[Ljava/util/ArrayList;)I
  */
 JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5AreadVL(JNIEnv *, jclass, jlong, jlong, jobjectArray);
 
 /*
  * Class:     hdf_hdf5lib_H5
  * Method:    H5AwriteVL
- * Signature: (JJ[Ljava/lang/String;)I
+ * Signature: (JJ[Ljava/util/ArrayList;)I
  */
 JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5AwriteVL(JNIEnv *, jclass, jlong, jlong, jobjectArray);
 
@@ -185,14 +185,14 @@ JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5Aread_1reg_1ref(JNIEnv *, jclass, j
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Aget_space
+ * Method:    _H5Aget_space
  * Signature: (J)J
  */
 JNIEXPORT jlong JNICALL Java_hdf_hdf5lib_H5__1H5Aget_1space(JNIEnv *, jclass, jlong);
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Aget_type
+ * Method:    _H5Aget_type
  * Signature: (J)J
  */
 JNIEXPORT jlong JNICALL Java_hdf_hdf5lib_H5__1H5Aget_1type(JNIEnv *, jclass, jlong);
@@ -220,7 +220,7 @@ JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5Adelete(JNIEnv *, jclass, jlong, js
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Aclose
+ * Method:    _H5Aclose
  * Signature: (J)I
  */
 JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5__1H5Aclose(JNIEnv *, jclass, jlong);
@@ -350,7 +350,7 @@ JNIEXPORT jlong JNICALL Java_hdf_hdf5lib_H5__1H5Aopen_1by_1name(JNIEnv *, jclass
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Aget_create_plist
+ * Method:    _H5Aget_create_plist
  * Signature: (J)J
  */
 JNIEXPORT jlong JNICALL Java_hdf_hdf5lib_H5__1H5Aget_1create_1plist(JNIEnv *, jclass, jlong);
diff --git a/java/src/jni/h5dImp.c b/java/src/jni/h5dImp.c
index 73b252a..a20bb6c 100644
--- a/java/src/jni/h5dImp.c
+++ b/java/src/jni/h5dImp.c
@@ -183,28 +183,24 @@ Java_hdf_hdf5lib_H5_H5Dread(JNIEnv *env, jclass clss, jlong dataset_id, jlong me
                             jboolean isCriticalPinning)
 {
     jboolean readBufIsCopy;
-    htri_t   data_class;
     jbyte *  readBuf = NULL;
-    herr_t   status  = FAIL;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dread: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_BYTE_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
                                 "H5Dread: read buffer not critically pinned");
@@ -219,6 +215,9 @@ Java_hdf_hdf5lib_H5_H5Dread(JNIEnv *env, jclass clss, jlong dataset_id, jlong me
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, readBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -241,28 +240,24 @@ Java_hdf_hdf5lib_H5_H5Dwrite(JNIEnv *env, jclass clss, jlong dataset_id, jlong m
                              jboolean isCriticalPinning)
 {
     jboolean writeBufIsCopy;
-    htri_t   data_class;
     jbyte *  writeBuf = NULL;
-    herr_t   status   = FAIL;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dwrite: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite:  variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_BYTE_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
                                 "H5Dwrite: write buffer not critically pinned");
@@ -277,6 +272,9 @@ Java_hdf_hdf5lib_H5_H5Dwrite(JNIEnv *env, jclass clss, jlong dataset_id, jlong m
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -383,7 +381,7 @@ Java_hdf_hdf5lib_H5_H5Dread_1short(JNIEnv *env, jclass clss, jlong dataset_id, j
 {
     jboolean readBufIsCopy;
     jshort * readBuf = NULL;
-    htri_t   data_class;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -391,19 +389,15 @@ Java_hdf_hdf5lib_H5_H5Dread_1short(JNIEnv *env, jclass clss, jlong dataset_id, j
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dread_short: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_short: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_short: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_SHORT_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
                                  "H5Dread_short: read buffer not critically pinned");
@@ -418,6 +412,9 @@ Java_hdf_hdf5lib_H5_H5Dread_1short(JNIEnv *env, jclass clss, jlong dataset_id, j
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, readBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -441,7 +438,7 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1short(JNIEnv *env, jclass clss, jlong dataset_id,
 {
     jboolean writeBufIsCopy;
     jshort * writeBuf = NULL;
-    htri_t   data_class;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -449,19 +446,15 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1short(JNIEnv *env, jclass clss, jlong dataset_id,
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_short: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_short: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_short: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_SHORT_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
                                  "H5Dwrite_short: write buffer not critically pinned");
@@ -476,6 +469,9 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1short(JNIEnv *env, jclass clss, jlong dataset_id,
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -498,28 +494,24 @@ Java_hdf_hdf5lib_H5_H5Dread_1int(JNIEnv *env, jclass clss, jlong dataset_id, jlo
                                  jboolean isCriticalPinning)
 {
     jboolean readBufIsCopy;
-    htri_t   data_class;
     jint *   readBuf = NULL;
-    herr_t   status  = FAIL;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dread_int: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_int: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_int: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_INT_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
                                "H5Dread_int: read buffer not critically pinned");
@@ -534,6 +526,9 @@ Java_hdf_hdf5lib_H5_H5Dread_1int(JNIEnv *env, jclass clss, jlong dataset_id, jlo
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, readBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -556,28 +551,24 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1int(JNIEnv *env, jclass clss, jlong dataset_id, jl
                                   jboolean isCriticalPinning)
 {
     jboolean writeBufIsCopy;
-    htri_t   data_class;
     jint *   writeBuf = NULL;
-    herr_t   status   = FAIL;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_int: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_int: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_int: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_INT_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
                                "H5Dwrite_int: write buffer not critically pinned");
@@ -592,6 +583,9 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1int(JNIEnv *env, jclass clss, jlong dataset_id, jl
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -614,28 +608,24 @@ Java_hdf_hdf5lib_H5_H5Dread_1long(JNIEnv *env, jclass clss, jlong dataset_id, jl
                                   jlongArray buf, jboolean isCriticalPinning)
 {
     jboolean readBufIsCopy;
-    htri_t   data_class;
     jlong *  readBuf = NULL;
-    herr_t   status  = FAIL;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dread_long: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_long: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_long: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_LONG_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
                                 "H5Dread_long: read buffer not critically pinned");
@@ -650,6 +640,9 @@ Java_hdf_hdf5lib_H5_H5Dread_1long(JNIEnv *env, jclass clss, jlong dataset_id, jl
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, readBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -672,28 +665,24 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1long(JNIEnv *env, jclass clss, jlong dataset_id, j
                                    jlongArray buf, jboolean isCriticalPinning)
 {
     jboolean writeBufIsCopy;
-    htri_t   data_class;
     jlong *  writeBuf = NULL;
-    herr_t   status   = FAIL;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_long: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_long: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_long: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_LONG_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
                                 "H5Dwrite_long: write buffer not critically pinned");
@@ -708,6 +697,9 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1long(JNIEnv *env, jclass clss, jlong dataset_id, j
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -730,28 +722,24 @@ Java_hdf_hdf5lib_H5_H5Dread_1float(JNIEnv *env, jclass clss, jlong dataset_id, j
                                    jfloatArray buf, jboolean isCriticalPinning)
 {
     jboolean readBufIsCopy;
-    htri_t   data_class;
     jfloat * readBuf = NULL;
-    herr_t   status  = FAIL;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dread_float: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_float: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_float: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_FLOAT_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
                                  "H5Dread_float: read buffer not critically pinned");
@@ -766,6 +754,9 @@ Java_hdf_hdf5lib_H5_H5Dread_1float(JNIEnv *env, jclass clss, jlong dataset_id, j
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, readBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -788,27 +779,23 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1float(JNIEnv *env, jclass clss, jlong dataset_id,
                                     jfloatArray buf, jboolean isCriticalPinning)
 {
     jboolean writeBufIsCopy;
-    htri_t   data_class;
     jfloat * writeBuf = NULL;
-    herr_t   status   = FAIL;
+    htri_t   vl_data_class;
+    herr_t   status = FAIL;
 
     UNUSED(clss);
 
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_float: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_float: variable length type not supported");
-
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_float: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread: readBuf length < 0");
+    }
 
     if (isCriticalPinning) {
         PIN_FLOAT_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
@@ -824,6 +811,9 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1float(JNIEnv *env, jclass clss, jlong dataset_id,
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -847,7 +837,7 @@ Java_hdf_hdf5lib_H5_H5Dread_1double(JNIEnv *env, jclass clss, jlong dataset_id,
 {
     jboolean readBufIsCopy;
     jdouble *readBuf = NULL;
-    htri_t   data_class;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -855,19 +845,15 @@ Java_hdf_hdf5lib_H5_H5Dread_1double(JNIEnv *env, jclass clss, jlong dataset_id,
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dread_double: read buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_double: variable length type not supported");
+    /* Get size of data array */
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Aread: readBuf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_double: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_DOUBLE_ARRAY_CRITICAL(ENVONLY, buf, readBuf, &readBufIsCopy,
                                   "H5Dread_double: read buffer not critically pinned");
@@ -882,6 +868,9 @@ Java_hdf_hdf5lib_H5_H5Dread_1double(JNIEnv *env, jclass clss, jlong dataset_id,
 
 done:
     if (readBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, readBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -905,7 +894,7 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1double(JNIEnv *env, jclass clss, jlong dataset_id,
 {
     jboolean writeBufIsCopy;
     jdouble *writeBuf = NULL;
-    htri_t   data_class;
+    htri_t   vl_data_class;
     herr_t   status = FAIL;
 
     UNUSED(clss);
@@ -913,19 +902,14 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1double(JNIEnv *env, jclass clss, jlong dataset_id,
     if (NULL == buf)
         H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_double: write buffer is NULL");
 
-    if ((data_class = H5Tdetect_class(mem_type_id, H5T_VLEN)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_double: variable length type not supported");
+    if (ENVPTR->GetArrayLength(ENVONLY, buf) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_double: buf length < 0");
+    }
 
-    /* Recursively detect any vlen string in type (compound, array ...) */
-    if ((data_class = H5Tdetect_variable_str(mem_type_id)) < 0)
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
 
-    if (data_class)
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_double: variable length type not supported");
-
     if (isCriticalPinning) {
         PIN_DOUBLE_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, &writeBufIsCopy,
                                   "H5Dwrite_double: write buffer not critically pinned");
@@ -940,6 +924,9 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1double(JNIEnv *env, jclass clss, jlong dataset_id,
 
 done:
     if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, writeBuf);
+
         if (isCriticalPinning) {
             UNPIN_ARRAY_CRITICAL(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
         }
@@ -1094,13 +1081,445 @@ done:
 /*
  * Class:     hdf_hdf5lib_H5
  * Method:    H5DreadVL
- * Signature: (JJJJJ[Ljava/lang/String;)I
+ * Signature: (JJJJJ[java/util/ArrayList;)I
  */
 JNIEXPORT jint JNICALL
 Java_hdf_hdf5lib_H5_H5DreadVL(JNIEnv *env, jclass clss, jlong dataset_id, jlong mem_type_id,
                               jlong mem_space_id, jlong file_space_id, jlong xfer_plist_id, jobjectArray buf)
 {
     H5T_class_t type_class;
+    jsize       n;
+    htri_t      vl_data_class;
+    herr_t      status = FAIL;
+    jboolean    readBufIsCopy;
+    jbyteArray *readBuf = NULL;
+
+    UNUSED(clss);
+
+    if (NULL == buf)
+        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5DreadVL: read buffer is NULL");
+
+    /* Get size of data array */
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5DreadVL: readBuf length < 0");
+    }
+
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+
+    if ((type_class = H5Tget_class((hid_t)mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+    if (type_class == H5T_VLEN) {
+        size_t      typeSize;
+        hid_t       memb = H5I_INVALID_HID;
+        H5T_class_t vlClass;
+        size_t      vlSize;
+        void *      rawBuf = NULL;
+        jobject *   jList  = NULL;
+
+        size_t i, j, x;
+        char * cp_vp = NULL;
+
+        if (!(typeSize = H5Tget_size(mem_type_id)))
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        if (!(memb = H5Tget_super(mem_type_id)))
+            H5_LIBRARY_ERROR(ENVONLY);
+        if ((vlClass = H5Tget_class((hid_t)memb)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+        if (!(vlSize = H5Tget_size(memb)))
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        if (NULL == (rawBuf = HDcalloc((size_t)n, typeSize)))
+            H5_OUT_OF_MEMORY_ERROR(ENVONLY, "H5DreadVL: failed to allocate raw VL read buffer");
+
+        if ((status = H5Dread((hid_t)dataset_id, (hid_t)mem_type_id, (hid_t)mem_space_id,
+                              (hid_t)file_space_id, (hid_t)xfer_plist_id, (void *)rawBuf)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        /* Cache class types */
+        jclass cBool   = ENVPTR->FindClass(ENVONLY, "java/lang/Boolean");
+        jclass cByte   = ENVPTR->FindClass(ENVONLY, "java/lang/Byte");
+        jclass cShort  = ENVPTR->FindClass(ENVONLY, "java/lang/Short");
+        jclass cInt    = ENVPTR->FindClass(ENVONLY, "java/lang/Integer");
+        jclass cLong   = ENVPTR->FindClass(ENVONLY, "java/lang/Long");
+        jclass cFloat  = ENVPTR->FindClass(ENVONLY, "java/lang/Float");
+        jclass cDouble = ENVPTR->FindClass(ENVONLY, "java/lang/Double");
+
+        jmethodID boolValueMid =
+            ENVPTR->GetStaticMethodID(ENVONLY, cBool, "valueOf", "(Z)Ljava/lang/Boolean;");
+        jmethodID byteValueMid = ENVPTR->GetStaticMethodID(ENVONLY, cByte, "valueOf", "(B)Ljava/lang/Byte;");
+        jmethodID shortValueMid =
+            ENVPTR->GetStaticMethodID(ENVONLY, cShort, "valueOf", "(S)Ljava/lang/Short;");
+        jmethodID intValueMid = ENVPTR->GetStaticMethodID(ENVONLY, cInt, "valueOf", "(I)Ljava/lang/Integer;");
+        jmethodID longValueMid = ENVPTR->GetStaticMethodID(ENVONLY, cLong, "valueOf", "(J)Ljava/lang/Long;");
+        jmethodID floatValueMid =
+            ENVPTR->GetStaticMethodID(ENVONLY, cFloat, "valueOf", "(F)Ljava/lang/Float;");
+        jmethodID doubleValueMid =
+            ENVPTR->GetStaticMethodID(ENVONLY, cDouble, "valueOf", "(D)Ljava/lang/Double;");
+
+        // retrieve the java.util.List interface class
+        jclass    cList     = ENVPTR->FindClass(ENVONLY, "java/util/List");
+        jmethodID addMethod = ENVPTR->GetMethodID(ENVONLY, cList, "add", "(Ljava/lang/Object;)Z");
+
+        /* Convert each element to a list */
+        for (i = 0; i < (size_t)n; i++) {
+            // The list we're going to return:
+            if (NULL == (jList = ENVPTR->GetObjectArrayElement(ENVONLY, (jobjectArray)buf, (jsize)i)))
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+            cp_vp = (char *)rawBuf + i * typeSize;
+            /* Get the number of sequence elements */
+            jsize nelmts = ((hvl_t *)cp_vp)->len;
+
+            jobject jobj = NULL;
+            for (j = 0; j < nelmts; j++) {
+                switch (vlClass) {
+                    /*case H5T_BOOL: {
+                        jboolean boolValue;
+                        for (x = 0; x < (int)vlSize; x++) {
+                            ((char *)&boolValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j*vlSize+x];
+                        }
+
+                        jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cBool, boolValueMid, boolValue);
+                        CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                        break;
+                    } */
+                    case H5T_INTEGER: {
+                        switch (vlSize) {
+                            case sizeof(jbyte): {
+                                jbyte byteValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&byteValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj =
+                                    ENVPTR->CallStaticObjectMethod(ENVONLY, cByte, byteValueMid, byteValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                            case sizeof(jshort): {
+                                jshort shortValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&shortValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cShort, shortValueMid,
+                                                                      shortValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                            case sizeof(jint): {
+                                jint intValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&intValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cInt, intValueMid, intValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                            case sizeof(jlong): {
+                                jlong longValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&longValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj =
+                                    ENVPTR->CallStaticObjectMethod(ENVONLY, cLong, longValueMid, longValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case H5T_FLOAT: {
+                        switch (vlSize) {
+                            case sizeof(jfloat): {
+                                jfloat floatValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&floatValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cFloat, floatValueMid,
+                                                                      floatValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                            case sizeof(jdouble): {
+                                jdouble doubleValue;
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)&doubleValue)[x] = ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                                }
+
+                                jobj = ENVPTR->CallStaticObjectMethod(ENVONLY, cDouble, doubleValueMid,
+                                                                      doubleValue);
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case H5T_REFERENCE: {
+                        jboolean bb;
+                        jbyte *  barray = NULL;
+                        if (NULL == (jobj = ENVPTR->NewByteArray(ENVONLY, vlSize)))
+                            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+                        PIN_BYTE_ARRAY(ENVONLY, (jbyteArray)jobj, barray, &bb,
+                                       "readVL reference: byte array not pinned");
+
+                        for (x = 0; x < (int)vlSize; x++) {
+                            barray[x] = ((jbyte *)((hvl_t *)cp_vp)->p)[j * vlSize + x];
+                        }
+                        if (barray)
+                            UNPIN_BYTE_ARRAY(ENVONLY, (jbyteArray)jobj, barray, jobj ? 0 : JNI_ABORT);
+                        break;
+                    }
+                    default:
+                        H5_UNIMPLEMENTED(ENVONLY, "H5DreadVL: invalid class type");
+                        break;
+                }
+
+                // Add it to the list
+                ENVPTR->CallBooleanMethod(ENVONLY, jList, addMethod, jobj);
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+            }
+        } /* end for */
+
+        if (rawBuf)
+            HDfree(rawBuf);
+    }
+    else {
+        if ((status = H5Dread((hid_t)dataset_id, (hid_t)mem_type_id, (hid_t)mem_space_id,
+                              (hid_t)file_space_id, (hid_t)xfer_plist_id, (void *)readBuf)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
+
+done:
+    if (readBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, readBuf);
+
+        UNPIN_BYTE_ARRAY(ENVONLY, buf, readBuf, (status < 0) ? JNI_ABORT : 0);
+    }
+
+    return (jint)status;
+} /* end Java_hdf_hdf5lib_H5_H5DreadVL */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5DwriteVL
+ * Signature: (JJJJJ[java/util/ArrayList;)I
+ */
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_H5_H5DwriteVL(JNIEnv *env, jclass clss, jlong dataset_id, jlong mem_type_id,
+                               jlong mem_space_id, jlong file_space_id, jlong xfer_plist_id, jobjectArray buf)
+{
+    H5T_class_t type_class;
+    jsize       n;
+    htri_t      vl_data_class;
+    herr_t      status = FAIL;
+    jboolean    writeBufIsCopy;
+    jbyteArray *writeBuf = NULL;
+
+    UNUSED(clss);
+
+    if (NULL == buf)
+        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5DwriteVL: write buffer is NULL");
+
+    /* Get size of data array */
+    if ((n = ENVPTR->GetArrayLength(ENVONLY, buf)) < 0) {
+        CHECK_JNI_EXCEPTION(ENVONLY, JNI_TRUE);
+        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5DwriteVL: readBuf length < 0");
+    }
+
+    if ((vl_data_class = h5str_detect_vlen(mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+
+    if ((type_class = H5Tget_class((hid_t)mem_type_id)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+    if (type_class == H5T_VLEN) {
+        size_t      typeSize;
+        hid_t       memb = H5I_INVALID_HID;
+        H5T_class_t vlClass;
+        size_t      vlSize;
+        void *      rawBuf = NULL;
+        jobject *   jList  = NULL;
+
+        size_t i, j, x;
+        char * cp_vp = NULL;
+
+        if (!(typeSize = H5Tget_size(mem_type_id)))
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        if (!(memb = H5Tget_super(mem_type_id)))
+            H5_LIBRARY_ERROR(ENVONLY);
+        if ((vlClass = H5Tget_class((hid_t)memb)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+        if (!(vlSize = H5Tget_size(memb)))
+            H5_LIBRARY_ERROR(ENVONLY);
+
+        if (NULL == (rawBuf = HDcalloc((size_t)n, typeSize)))
+            H5_OUT_OF_MEMORY_ERROR(ENVONLY, "H5DwriteVL: failed to allocate raw VL write buffer");
+
+        /* Cache class types */
+        jclass cBool   = ENVPTR->FindClass(ENVONLY, "java/lang/Boolean");
+        jclass cByte   = ENVPTR->FindClass(ENVONLY, "java/lang/Byte");
+        jclass cShort  = ENVPTR->FindClass(ENVONLY, "java/lang/Short");
+        jclass cInt    = ENVPTR->FindClass(ENVONLY, "java/lang/Integer");
+        jclass cLong   = ENVPTR->FindClass(ENVONLY, "java/lang/Long");
+        jclass cFloat  = ENVPTR->FindClass(ENVONLY, "java/lang/Float");
+        jclass cDouble = ENVPTR->FindClass(ENVONLY, "java/lang/Double");
+
+        jmethodID boolValueMid   = ENVPTR->GetMethodID(ENVONLY, cBool, "booleanValue", "()Z");
+        jmethodID byteValueMid   = ENVPTR->GetMethodID(ENVONLY, cByte, "byteValue", "()B");
+        jmethodID shortValueMid  = ENVPTR->GetMethodID(ENVONLY, cShort, "shortValue", "()S");
+        jmethodID intValueMid    = ENVPTR->GetMethodID(ENVONLY, cInt, "intValue", "()I");
+        jmethodID longValueMid   = ENVPTR->GetMethodID(ENVONLY, cLong, "longValue", "()J");
+        jmethodID floatValueMid  = ENVPTR->GetMethodID(ENVONLY, cFloat, "floatValue", "()F");
+        jmethodID doubleValueMid = ENVPTR->GetMethodID(ENVONLY, cDouble, "doubleValue", "()D");
+
+        /* Convert each list to a vlen element */
+        for (i = 0; i < (size_t)n; i++) {
+            if (NULL == (jList = ENVPTR->GetObjectArrayElement(ENVONLY, (jobjectArray)buf, (jsize)i)))
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+            // retrieve the java.util.List interface class
+            jclass cList = ENVPTR->FindClass(ENVONLY, "java/util/List");
+
+            // retrieve the toArray method and invoke it
+            jmethodID mToArray = ENVPTR->GetMethodID(ENVONLY, cList, "toArray", "()[Ljava/lang/Object;");
+            if (mToArray == NULL)
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+            jobjectArray array   = (jobjectArray)ENVPTR->CallObjectMethod(ENVONLY, jList, mToArray);
+            jsize        jnelmts = ENVPTR->GetArrayLength(ENVONLY, array);
+
+            cp_vp                 = (char *)rawBuf + i * typeSize;
+            ((hvl_t *)cp_vp)->len = jnelmts;
+
+            if (NULL == (((hvl_t *)cp_vp)->p = HDmalloc(jnelmts * vlSize)))
+                H5_OUT_OF_MEMORY_ERROR(ENVONLY, "H5DwriteVL: failed to allocate vlen ptr buffer");
+            jobject jobj = NULL;
+            for (j = 0; j < (int)jnelmts; j++) {
+                if (NULL == (jobj = ENVPTR->GetObjectArrayElement(ENVONLY, (jobjectArray)array, (jsize)j)))
+                    CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+                switch (vlClass) {
+                    /* case H5T_BOOL: {
+                            jboolean boolValue = ENVPTR->CallBooleanMethod(ENVONLY, jobj, boolValueMid);
+                            for (x = 0; x < (int)vlSize; x++) {
+                                ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&boolValue)[x];
+                            }
+                            break;
+                    } */
+                    case H5T_INTEGER: {
+                        switch (vlSize) {
+                            case sizeof(jbyte): {
+                                jbyte byteValue = ENVPTR->CallByteMethod(ENVONLY, jobj, byteValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&byteValue)[x];
+                                }
+                                break;
+                            }
+                            case sizeof(jshort): {
+                                jshort shortValue = ENVPTR->CallShortMethod(ENVONLY, jobj, shortValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&shortValue)[x];
+                                }
+                                break;
+                            }
+                            case sizeof(jint): {
+                                jint intValue = ENVPTR->CallIntMethod(ENVONLY, jobj, intValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&intValue)[x];
+                                }
+                                break;
+                            }
+                            case sizeof(jlong): {
+                                jlong longValue = ENVPTR->CallLongMethod(ENVONLY, jobj, longValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&longValue)[x];
+                                }
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case H5T_FLOAT: {
+                        switch (vlSize) {
+                            case sizeof(jfloat): {
+                                jfloat floatValue = ENVPTR->CallFloatMethod(ENVONLY, jobj, floatValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&floatValue)[x];
+                                }
+                                break;
+                            }
+                            case sizeof(jdouble): {
+                                jdouble doubleValue = ENVPTR->CallDoubleMethod(ENVONLY, jobj, doubleValueMid);
+                                for (x = 0; x < (int)vlSize; x++) {
+                                    ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)&doubleValue)[x];
+                                }
+                                break;
+                            }
+                        }
+                        break;
+                    }
+                    case H5T_REFERENCE: {
+                        jbyte *barray = (jbyte *)ENVPTR->GetByteArrayElements(ENVONLY, jobj, 0);
+                        for (x = 0; x < (int)vlSize; x++) {
+                            ((char *)((hvl_t *)cp_vp)->p)[j * vlSize + x] = ((char *)barray)[x];
+                        }
+                        ENVPTR->ReleaseByteArrayElements(ENVONLY, jobj, barray, 0);
+                        break;
+                    }
+                    default:
+                        H5_UNIMPLEMENTED(ENVONLY, "H5DwriteVL: invalid class type");
+                        break;
+                }
+                ENVPTR->DeleteLocalRef(ENVONLY, jobj);
+            }
+            ENVPTR->DeleteLocalRef(ENVONLY, jList);
+        } /* end for (i = 0; i < n; i++) */
+
+        if ((status = H5Dwrite((hid_t)dataset_id, (hid_t)mem_type_id, (hid_t)mem_space_id,
+                               (hid_t)file_space_id, (hid_t)xfer_plist_id, rawBuf)) < 0)
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+        if (rawBuf)
+            HDfree(rawBuf);
+    }
+    else {
+        PIN_BYTE_ARRAY(ENVONLY, buf, writeBuf, &writeBufIsCopy, "H5DwriteVL: write buffer not pinned");
+        if ((status = H5Dwrite((hid_t)dataset_id, (hid_t)mem_type_id, (hid_t)mem_space_id,
+                               (hid_t)file_space_id, (hid_t)xfer_plist_id, writeBuf)) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    }
+
+done:
+    if (writeBuf) {
+        if ((status >= 0) && vl_data_class)
+            H5Treclaim(dataset_id, mem_space_id, H5P_DEFAULT, writeBuf);
+
+        if (type_class != H5T_VLEN)
+            UNPIN_BYTE_ARRAY(ENVONLY, buf, writeBuf, (status < 0) ? JNI_ABORT : 0);
+    }
+
+    return (jint)status;
+} /* end Java_hdf_hdf5lib_H5_H5DwriteVL */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5Dread_VLStrings
+ * Signature: (JJJJJ[Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_H5_H5Dread_1VLStrings(JNIEnv *env, jclass clss, jlong dataset_id, jlong mem_type_id,
+                                       jlong mem_space_id, jlong file_space_id, jlong xfer_plist_id,
+                                       jobjectArray buf)
+{
+    H5T_class_t type_class;
     htri_t      isStr      = 0;
     htri_t      isVlenStr  = 0;
     htri_t      isComplex  = 0;
@@ -1111,7 +1530,7 @@ Java_hdf_hdf5lib_H5_H5DreadVL(JNIEnv *env, jclass clss, jlong dataset_id, jlong
     UNUSED(clss);
 
     if (NULL == buf)
-        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5DreadVL: read buffer is NULL");
+        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5DreadVLStrings: read buffer is NULL");
 
     if ((isStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
@@ -1163,7 +1582,7 @@ done:
         H5Tclose(nested_tid);
 
     return (jint)status;
-} /* end Java_hdf_hdf5lib_H5_H5Dread_1VL */
+} /* end Java_hdf_hdf5lib_H5_H5Dread_1VLStrings */
 
 /*
  * Helper method to read in a buffer of variable-length strings from an HDF5
@@ -1315,54 +1734,15 @@ done:
     return status;
 }
 
-/**
- *  Read VLEN data into array of arrays.
- *  Object[] buf contains VL arrays of data points
- *  Currently only deal with variable length of atomic data types
- */
-/* old version */
-
-/*
- * Class:     hdf_hdf5lib_H5
- * Method:    H5Dread_VLStrings
- * Signature: (JJJJJ[Ljava/lang/String;)I
- */
-JNIEXPORT jint JNICALL
-Java_hdf_hdf5lib_H5_H5Dread_1VLStrings(JNIEnv *env, jclass clss, jlong dataset_id, jlong mem_type_id,
-                                       jlong mem_space_id, jlong file_space_id, jlong xfer_plist_id,
-                                       jobjectArray buf)
-{
-    htri_t isVlenStr = 0;
-    herr_t status    = FAIL;
-
-    UNUSED(clss);
-
-    if (NULL == buf)
-        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dread_VLStrings: read buffer is NULL");
-
-    if ((isVlenStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (isVlenStr) {
-        if ((status = H5DreadVL_str(env, (hid_t)dataset_id, (hid_t)mem_type_id, (hid_t)mem_space_id,
-                                    (hid_t)file_space_id, (hid_t)xfer_plist_id, buf)) < 0)
-            H5_LIBRARY_ERROR(ENVONLY);
-    }
-    else
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dread_VLStrings: datatype is not variable length String");
-
-done:
-    return (jint)status;
-} /* end Java_hdf_hdf5lib_H5_H5Dread_1VLStrings */
-
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5DwriteVL
+ * Method:    H5Dwrite_VLStrings
  * Signature: (JJJJJ[Ljava/lang/String;)I
  */
 JNIEXPORT jint JNICALL
-Java_hdf_hdf5lib_H5_H5DwriteVL(JNIEnv *env, jclass clss, jlong dataset_id, jlong mem_type_id,
-                               jlong mem_space_id, jlong file_space_id, jlong xfer_plist_id, jobjectArray buf)
+Java_hdf_hdf5lib_H5_H5Dwrite_1VLStrings(JNIEnv *env, jclass clss, jlong dataset_id, jlong mem_type_id,
+                                        jlong mem_space_id, jlong file_space_id, jlong xfer_plist_id,
+                                        jobjectArray buf)
 {
     H5T_class_t type_class;
     htri_t      isStr      = 0;
@@ -1375,7 +1755,7 @@ Java_hdf_hdf5lib_H5_H5DwriteVL(JNIEnv *env, jclass clss, jlong dataset_id, jlong
     UNUSED(clss);
 
     if (NULL == buf)
-        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5DwriteVL: write buffer is NULL");
+        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5DwriteVLStrings: write buffer is NULL");
 
     if ((isStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING)) < 0)
         H5_LIBRARY_ERROR(ENVONLY);
@@ -1427,7 +1807,7 @@ done:
         H5Tclose(nested_tid);
 
     return (jint)status;
-} /* end Java_hdf_hdf5lib_H5_H5Dwrite_1VL */
+} /* end Java_hdf_hdf5lib_H5_H5Dwrite_1VLStrings */
 
 /*
  * Helper method to convert an array of Java strings into a buffer of C-strings.
@@ -1440,7 +1820,7 @@ H5DwriteVL_str(JNIEnv *env, hid_t dataset_id, hid_t mem_type_id, hid_t mem_space
     const char *utf8 = NULL;
     jstring     obj;
     jsize       size;
-    jsize       i;
+    jint        i;
     char **     writeBuf = NULL;
     herr_t      status   = FAIL;
 
@@ -1512,7 +1892,7 @@ H5DwriteVL_asstr(JNIEnv *env, hid_t did, hid_t tid, hid_t mem_sid, hid_t file_si
                  jobjectArray buf)
 {
     const char *utf8            = NULL;
-    jstring     obj             = NULL;
+    jstring     jstr            = NULL;
     hbool_t     close_mem_space = FALSE;
     size_t      typeSize;
     size_t      i;
@@ -1549,7 +1929,7 @@ H5DwriteVL_asstr(JNIEnv *env, hid_t did, hid_t tid, hid_t mem_sid, hid_t file_si
         H5_OUT_OF_MEMORY_ERROR(ENVONLY, "H5AwriteVL_asstr: failed to allocate write buffer");
 
     for (i = 0; i < (size_t)n; ++i) {
-        if (NULL == (obj = (jstring)ENVPTR->GetObjectArrayElement(ENVONLY, (jobjectArray)buf, (jsize)i))) {
+        if (NULL == (jstr = (jstring)ENVPTR->GetObjectArrayElement(ENVONLY, (jobjectArray)buf, (jsize)i))) {
             CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
 
             /*
@@ -1560,11 +1940,11 @@ H5DwriteVL_asstr(JNIEnv *env, hid_t did, hid_t tid, hid_t mem_sid, hid_t file_si
         }
 
         /*
-         * length = ENVPTR->GetStringUTFLength(ENVONLY, obj);
+         * length = ENVPTR->GetStringUTFLength(ENVONLY, jstr);
          * CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
          */
 
-        PIN_JAVA_STRING(ENVONLY, obj, utf8, NULL, "H5DwriteVL_asstr: failed to pin string buffer");
+        PIN_JAVA_STRING(ENVONLY, jstr, utf8, NULL, "H5DwriteVL_asstr: failed to pin string buffer");
 
         /*
          * TODO: If the string isn't a copy, we should probably make
@@ -1574,10 +1954,10 @@ H5DwriteVL_asstr(JNIEnv *env, hid_t did, hid_t tid, hid_t mem_sid, hid_t file_si
         if (!h5str_convert(ENVONLY, (char **)&utf8, did, tid, &(((char *)writeBuf)[i * typeSize]), 0))
             CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
 
-        UNPIN_JAVA_STRING(ENVONLY, obj, utf8);
+        UNPIN_JAVA_STRING(ENVONLY, jstr, utf8);
         utf8 = NULL;
 
-        ENVPTR->DeleteLocalRef(ENVONLY, obj);
+        ENVPTR->DeleteLocalRef(ENVONLY, jstr);
     } /* end for (i = 0; i < size; ++i) */
 
     if ((status = H5Dwrite(did, tid, mem_sid, file_sid, xfer_plist_id, writeBuf)) < 0)
@@ -1585,7 +1965,7 @@ H5DwriteVL_asstr(JNIEnv *env, hid_t did, hid_t tid, hid_t mem_sid, hid_t file_si
 
 done:
     if (utf8)
-        UNPIN_JAVA_STRING(ENVONLY, obj, utf8);
+        UNPIN_JAVA_STRING(ENVONLY, jstr, utf8);
     if (writeBuf) {
         H5Treclaim(tid, mem_space, xfer_plist_id, writeBuf);
         HDfree(writeBuf);
@@ -1598,39 +1978,6 @@ done:
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5Dwrite_VLStrings
- * Signature: (JJJJJ[Ljava/lang/String;)I
- */
-JNIEXPORT jint JNICALL
-Java_hdf_hdf5lib_H5_H5Dwrite_1VLStrings(JNIEnv *env, jclass clss, jlong dataset_id, jlong mem_type_id,
-                                        jlong mem_space_id, jlong file_space_id, jlong xfer_plist_id,
-                                        jobjectArray buf)
-{
-    htri_t isVlenStr = 0;
-    herr_t status    = FAIL;
-
-    UNUSED(clss);
-
-    if (NULL == buf)
-        H5_NULL_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_VLStrings: write buffer is NULL");
-
-    if ((isVlenStr = H5Tis_variable_str((hid_t)mem_type_id)) < 0)
-        H5_LIBRARY_ERROR(ENVONLY);
-
-    if (isVlenStr) {
-        if ((status = H5DwriteVL_str(env, (hid_t)dataset_id, (hid_t)mem_type_id, (hid_t)mem_space_id,
-                                     (hid_t)file_space_id, (hid_t)xfer_plist_id, buf)) < 0)
-            H5_LIBRARY_ERROR(ENVONLY);
-    } /* end if */
-    else
-        H5_BAD_ARGUMENT_ERROR(ENVONLY, "H5Dwrite_VLStrings: datatype is not variable length String");
-
-done:
-    return (jint)status;
-} /* end Java_hdf_hdf5lib_H5_H5Dwrite_1VLStrings */
-
-/*
- * Class:     hdf_hdf5lib_H5
  * Method:    H5Dread_reg_ref
  * Signature: (JJJJJ[Ljava/lang/String;)I
  */
diff --git a/java/src/jni/h5dImp.h b/java/src/jni/h5dImp.h
index e339dad..f79cc2c 100644
--- a/java/src/jni/h5dImp.h
+++ b/java/src/jni/h5dImp.h
@@ -177,7 +177,7 @@ JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5Dwrite_1double(JNIEnv *, jclass, jl
 /*
  * Class:     hdf_hdf5lib_H5
  * Method:    H5DreadVL
- * Signature: (JJJJJ[Ljava/lang/String;)I
+ * Signature: (JJJJJ[Ljava/util/ArrayList;)I
  */
 JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5DreadVL(JNIEnv *, jclass, jlong, jlong, jlong, jlong, jlong,
                                                      jobjectArray);
@@ -185,7 +185,7 @@ JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5DreadVL(JNIEnv *, jclass, jlong, jl
 /*
  * Class:     hdf_hdf5lib_H5
  * Method:    H5DwriteVL
- * Signature: (JJJJJ[Ljava/lang/String;)I
+ * Signature: (JJJJJ[Ljava/util/ArrayList;)I
  */
 JNIEXPORT jint JNICALL Java_hdf_hdf5lib_H5_H5DwriteVL(JNIEnv *, jclass, jlong, jlong, jlong, jlong, jlong,
                                                       jobjectArray);
diff --git a/java/src/jni/h5util.c b/java/src/jni/h5util.c
index 2de5d87..966bee5 100644
--- a/java/src/jni/h5util.c
+++ b/java/src/jni/h5util.c
@@ -52,6 +52,7 @@ void *      edata;
 /* Local Prototypes */
 /********************/
 
+int h5str_old_region_dataset(JNIEnv *env, h5str_t *out_str, hid_t container, void *ref_buf, int expand_data);
 int h5str_region_dataset(JNIEnv *env, h5str_t *out_str, H5R_ref_t *ref_vp, int expand_data);
 
 static int    h5str_dump_region_blocks(JNIEnv *env, h5str_t *str, hid_t region, hid_t region_obj,
@@ -63,7 +64,6 @@ static int    h5str_is_zero(const void *_mem, size_t size);
 static hid_t  h5str_get_native_type(hid_t type);
 static hid_t  h5str_get_little_endian_type(hid_t type);
 static hid_t  h5str_get_big_endian_type(hid_t type);
-static htri_t h5str_detect_vlen(hid_t tid);
 static htri_t h5str_detect_vlen_str(hid_t tid);
 static int    h5str_dump_simple_data(JNIEnv *env, FILE *stream, hid_t container, hid_t type, void *_mem,
                                      hsize_t nelmts);
@@ -642,6 +642,33 @@ done:
 } /* end h5str_convert */
 
 /*-------------------------------------------------------------------------
+ * Function:    h5str_sprint_old_reference
+ *
+ * Purpose: Object reference -- show the name of the 1.10 referenced object.
+ *
+ * Return:  SUCCEED or FAIL
+ *-------------------------------------------------------------------------
+ */
+int
+h5str_sprint_old_reference(JNIEnv *env, h5str_t *out_str, hid_t region_obj, void *ref_buf)
+{
+    hid_t region = H5I_INVALID_HID;
+    char  ref_name[1024];
+
+    int ret_value = FAIL;
+
+    if ((H5Rget_name(region_obj, H5R_DATASET_REGION, ref_buf, (char *)ref_name, 1024)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+    if (!h5str_append(out_str, ref_name))
+        H5_ASSERTION_ERROR(ENVONLY, "Unable to append string.");
+
+    ret_value = SUCCEED;
+done:
+
+    return ret_value;
+} /* h5str_sprint_reference */
+
+/*-------------------------------------------------------------------------
  * Function:    h5str_sprint_reference
  *
  * Purpose: Object reference -- show the name of the referenced object.
@@ -705,6 +732,48 @@ done:
 } /* h5str_sprint_reference */
 
 int
+h5str_old_region_dataset(JNIEnv *env, h5str_t *out_str, hid_t container, void *ref_buf, int expand_data)
+{
+    H5S_sel_type region_type = H5S_SEL_ERROR;
+    hid_t        region_obj  = H5I_INVALID_HID;
+    hid_t        region_sid  = H5I_INVALID_HID;
+
+    int ret_value = FAIL;
+
+    if ((region_obj = H5Rdereference2(container, H5P_DEFAULT, H5R_DATASET_REGION, ref_buf)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+
+    if ((region_sid = H5Rget_region(container, H5R_DATASET_REGION, ref_buf)) < 0)
+        H5_LIBRARY_ERROR(ENVONLY);
+
+    if (expand_data == 0)
+        if (h5str_sprint_old_reference(ENVONLY, out_str, region_obj, ref_buf) < 0)
+            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+    if ((region_type = H5Sget_select_type(region_sid)) > H5S_SEL_ERROR) {
+        if (H5S_SEL_POINTS == region_type) {
+            if (h5str_dump_region_points(ENVONLY, out_str, region_sid, region_obj, expand_data) < 0)
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+        }
+        else if (H5S_SEL_HYPERSLABS == region_type) {
+            if (h5str_dump_region_blocks(ENVONLY, out_str, region_sid, region_obj, expand_data) < 0)
+                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+        }
+    }
+
+    ret_value = SUCCEED;
+done:
+    if (region_sid >= 0)
+        if (H5Sclose(region_sid) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+    if (region_obj >= 0)
+        if (H5Dclose(region_obj) < 0)
+            H5_LIBRARY_ERROR(ENVONLY);
+
+    return ret_value;
+}
+
+int
 h5str_region_dataset(JNIEnv *env, h5str_t *out_str, H5R_ref_t *ref_vp, int expand_data)
 {
     hid_t        new_obj_id  = H5I_INVALID_HID;
@@ -1106,125 +1175,209 @@ h5str_sprintf(JNIEnv *env, h5str_t *out_str, hid_t container, hid_t tid, void *i
         }
 
         case H5T_REFERENCE: {
-            /* H5T_STD_REF */
-            hid_t      new_obj_id = H5I_INVALID_HID;
-            H5O_type_t obj_type   = -1; /* Object type */
-            H5R_type_t ref_type;        /* Reference type */
-
-            H5R_ref_t *ref_vp = (H5R_ref_t *)cptr;
-
-            ref_type = H5Rget_type(ref_vp);
-            if (!h5str_is_zero(ref_vp, H5Tget_size(H5T_STD_REF))) {
-                switch (ref_type) {
-                    case H5R_OBJECT1:
-                        if (H5Rget_obj_type3(ref_vp, H5P_DEFAULT, &obj_type) >= 0) {
-                            switch (obj_type) {
-                                case H5O_TYPE_DATASET:
-                                    if (h5str_region_dataset(ENVONLY, out_str, ref_vp, expand_data) < 0)
-                                        CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
-                                    break;
-
-                                case H5O_TYPE_GROUP:
-                                case H5O_TYPE_NAMED_DATATYPE:
-                                case H5O_TYPE_MAP:
-                                case H5O_TYPE_UNKNOWN:
-                                case H5O_TYPE_NTYPES:
-                                default: {
-                                    /* Object references -- show the type and OID of the referenced object. */
-                                    H5O_info2_t oi;
-                                    char *      obj_tok_str = NULL;
-                                    if ((new_obj_id = H5Ropen_object(ref_vp, H5P_DEFAULT, H5P_DEFAULT)) >=
-                                        0) {
-                                        H5Oget_info3(new_obj_id, &oi, H5O_INFO_BASIC);
-                                        H5Otoken_to_str(new_obj_id, &oi.token, &obj_tok_str);
-                                        if (H5Dclose(new_obj_id) < 0)
-                                            H5_LIBRARY_ERROR(ENVONLY);
-                                    }
-                                    else
-                                        H5_LIBRARY_ERROR(ENVONLY);
-
-                                    size_t this_len = 14;
-                                    if (NULL == (this_str = (char *)HDmalloc(this_len)))
-                                        H5_OUT_OF_MEMORY_ERROR(
-                                            ENVONLY, "h5str_sprintf: failed to allocate string buffer");
-                                    if (HDsnprintf(this_str, this_len, "%u-", (unsigned)oi.type) < 0)
-                                        H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: HDsnprintf failure");
-                                    if (!h5str_append(out_str, this_str))
-                                        H5_ASSERTION_ERROR(ENVONLY, "Unable to append string.");
-                                    HDfree(this_str);
-                                    this_str = NULL;
-
-                                    /* Print OID */
-                                    {
-                                        char *token_str;
-
-                                        H5Otoken_to_str(tid, &oi.token, &token_str);
-
-                                        size_t that_len = 64 + strlen(token_str) + 1;
-                                        if (NULL == (this_str = HDmalloc(that_len)))
-                                            H5_OUT_OF_MEMORY_ERROR(
-                                                ENVONLY, "h5str_sprintf: failed to allocate string buffer");
-                                        if (HDsnprintf(this_str, that_len, "%lu:%s", oi.fileno, token_str) <
-                                            0)
-                                            H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: HDsnprintf failure");
-
-                                        H5free_memory(token_str);
-                                    }
-                                } break;
-                            } /* end switch */
-                        }
-                        else
-                            H5_LIBRARY_ERROR(ENVONLY);
-                        break;
-                    case H5R_DATASET_REGION1:
-                        if (h5str_region_dataset(ENVONLY, out_str, ref_vp, expand_data) < 0)
-                            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
-                        break;
-                    case H5R_OBJECT2:
-                        if (H5Rget_obj_type3(ref_vp, H5P_DEFAULT, &obj_type) >= 0) {
-                            switch (obj_type) {
-                                case H5O_TYPE_GROUP:
-                                    break;
-
-                                case H5O_TYPE_DATASET:
-                                    if (h5str_region_dataset(ENVONLY, out_str, ref_vp, expand_data) < 0)
-                                        CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
-                                    break;
-
-                                case H5O_TYPE_NAMED_DATATYPE:
-                                    break;
-
-                                case H5O_TYPE_MAP:
-                                case H5O_TYPE_UNKNOWN:
-                                case H5O_TYPE_NTYPES:
-                                default:
-                                    break;
-                            } /* end switch */
-                        }
-                        else
-                            H5_ASSERTION_ERROR(ENVONLY, "h5str_sprintf: H5R_OBJECT2 failed");
+            if (H5R_DSET_REG_REF_BUF_SIZE == typeSize) {
+                if (h5str_old_region_dataset(ENVONLY, out_str, container, cptr, expand_data) < 0)
+                    CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+            }
+            else if (H5R_OBJ_REF_BUF_SIZE == typeSize) {
+                H5O_info1_t oi;
+                hid_t       obj = H5I_INVALID_HID;
+
+                /*
+                 * Object references -- show the type and OID of the referenced
+                 * object.
+                 */
+
+                if (NULL == (this_str = (char *)HDmalloc(64)))
+                    H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: failed to allocate string buffer");
+
+                if ((obj = H5Rdereference2(container, H5P_DEFAULT, H5R_OBJECT, cptr)) < 0)
+                    H5_LIBRARY_ERROR(ENVONLY);
+
+                if (H5Oget_info2(obj, &oi, H5O_INFO_ALL) < 0)
+                    H5_LIBRARY_ERROR(ENVONLY);
+
+                /* Print object data and close object */
+                switch (oi.type) {
+                    case H5O_TYPE_GROUP:
+                        if (HDsprintf(this_str, "%s %llu", H5_TOOLS_GROUP, oi.addr) < 0)
+                            H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: HDsprintf failure");
                         break;
-                    case H5R_DATASET_REGION2:
-                        if (h5str_region_dataset(ENVONLY, out_str, ref_vp, expand_data) < 0)
-                            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+
+                    case H5O_TYPE_DATASET:
+                        if (HDsprintf(this_str, "%s %llu", H5_TOOLS_DATASET, oi.addr) < 0)
+                            H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: HDsprintf failure");
                         break;
-                    case H5R_ATTR:
-                        if ((new_obj_id = H5Ropen_attr(ref_vp, H5P_DEFAULT, H5P_DEFAULT)) >= 0) {
-                            if (h5str_dump_region_attribute(ENVONLY, out_str, new_obj_id) < 0)
-                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
-                            if (H5Aclose(new_obj_id) < 0)
-                                H5_LIBRARY_ERROR(ENVONLY);
-                        }
+
+                    case H5O_TYPE_NAMED_DATATYPE:
+                        if (HDsprintf(this_str, "%s %llu", H5_TOOLS_DATATYPE, oi.addr) < 0)
+                            H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: HDsprintf failure");
                         break;
-                    case H5R_BADTYPE:
-                    case H5R_MAXTYPE:
+
+                    case H5O_TYPE_UNKNOWN:
+                    case H5O_TYPE_NTYPES:
                     default:
+                        if (HDsprintf(this_str, "%u-%llu", (unsigned)oi.type, oi.addr) < 0)
+                            H5_JNI_FATAL_ERROR(ENVONLY, "h5str_sprintf: HDsprintf failure");
                         break;
                 } /* end switch */
+
+                if (H5Oclose(obj) < 0)
+                    H5_LIBRARY_ERROR(ENVONLY);
+                obj = H5I_INVALID_HID;
             }
+            else {
+                /* H5T_STD_REF */
+                hid_t      new_obj_id = H5I_INVALID_HID;
+                H5O_type_t obj_type   = -1; /* Object type */
+                H5R_type_t ref_type;        /* Reference type */
+
+                H5R_ref_t *ref_vp = (H5R_ref_t *)cptr;
+
+                ref_type = H5Rget_type(ref_vp);
+                if (!h5str_is_zero(ref_vp, H5Tget_size(H5T_STD_REF))) {
+                    switch (ref_type) {
+                        case H5R_OBJECT1:
+                            if (H5Rget_obj_type3(ref_vp, H5P_DEFAULT, &obj_type) >= 0) {
+                                switch (obj_type) {
+                                    case H5O_TYPE_DATASET:
+                                        if (h5str_region_dataset(ENVONLY, out_str, ref_vp, expand_data) < 0)
+                                            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                        break;
+
+                                    case H5O_TYPE_GROUP:
+                                    case H5O_TYPE_NAMED_DATATYPE:
+                                    case H5O_TYPE_MAP:
+                                    case H5O_TYPE_UNKNOWN:
+                                    case H5O_TYPE_NTYPES:
+                                    default: {
+                                        /* Object references -- show the type and
+                                         * OID of the referenced object. */
+                                        H5O_info2_t oi;
+                                        char *      obj_tok_str = NULL;
+                                        if ((new_obj_id = H5Ropen_object(ref_vp, H5P_DEFAULT, H5P_DEFAULT)) >=
+                                            0) {
+                                            H5Oget_info3(new_obj_id, &oi, H5O_INFO_BASIC);
+                                            H5Otoken_to_str(new_obj_id, &oi.token, &obj_tok_str);
+                                            if (H5Dclose(new_obj_id) < 0)
+                                                H5_LIBRARY_ERROR(ENVONLY);
+                                        }
+                                        else
+                                            H5_LIBRARY_ERROR(ENVONLY);
 
-            if (H5Rdestroy(ref_vp) < 0)
-                H5_LIBRARY_ERROR(ENVONLY);
+                                        size_t this_len = 14;
+                                        if (NULL == (this_str = (char *)HDmalloc(this_len)))
+                                            H5_OUT_OF_MEMORY_ERROR(
+                                                ENVONLY, "h5str_sprintf: failed to allocate string buffer");
+                                        switch (oi.type) {
+                                            case H5O_TYPE_GROUP:
+                                                if (HDsnprintf(this_str, this_len, "%s ", H5_TOOLS_GROUP) < 0)
+                                                    H5_JNI_FATAL_ERROR(ENVONLY,
+                                                                       "h5str_sprintf: HDsnprintf failure");
+                                                break;
+
+                                            case H5O_TYPE_DATASET:
+                                                if (HDsnprintf(this_str, this_len, "%s ", H5_TOOLS_DATASET) <
+                                                    0)
+                                                    H5_JNI_FATAL_ERROR(ENVONLY,
+                                                                       "h5str_sprintf: HDsnprintf failure");
+                                                break;
+
+                                            case H5O_TYPE_NAMED_DATATYPE:
+                                                if (HDsnprintf(this_str, this_len, "%s ", H5_TOOLS_DATATYPE) <
+                                                    0)
+                                                    H5_JNI_FATAL_ERROR(ENVONLY,
+                                                                       "h5str_sprintf: HDsnprintf failure");
+                                                break;
+
+                                            case H5O_TYPE_UNKNOWN:
+                                            case H5O_TYPE_NTYPES:
+                                            default:
+                                                if (HDsnprintf(this_str, this_len, "%u-", (unsigned)oi.type) <
+                                                    0)
+                                                    H5_JNI_FATAL_ERROR(ENVONLY,
+                                                                       "h5str_sprintf: HDsnprintf failure");
+                                                break;
+                                        } /* end switch */
+                                        if (!h5str_append(out_str, this_str))
+                                            H5_ASSERTION_ERROR(ENVONLY, "Unable to append string.");
+                                        HDfree(this_str);
+                                        this_str = NULL;
+
+                                        /* Print OID */
+                                        {
+                                            char *token_str;
+
+                                            H5Otoken_to_str(tid, &oi.token, &token_str);
+
+                                            size_t that_len = 64 + strlen(token_str) + 1;
+                                            if (NULL == (this_str = HDmalloc(that_len)))
+                                                H5_OUT_OF_MEMORY_ERROR(
+                                                    ENVONLY,
+                                                    "h5str_sprintf: failed to allocate string buffer");
+                                            if (HDsnprintf(this_str, that_len, "%lu:%s", oi.fileno,
+                                                           token_str) < 0)
+                                                H5_JNI_FATAL_ERROR(ENVONLY,
+                                                                   "h5str_sprintf: HDsnprintf failure");
+
+                                            H5free_memory(token_str);
+                                        }
+                                    } break;
+                                } /* end switch */
+                            }
+                            else
+                                H5_LIBRARY_ERROR(ENVONLY);
+                            break;
+                        case H5R_DATASET_REGION1:
+                            if (h5str_region_dataset(ENVONLY, out_str, ref_vp, expand_data) < 0)
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                            break;
+                        case H5R_OBJECT2:
+                            if (H5Rget_obj_type3(ref_vp, H5P_DEFAULT, &obj_type) >= 0) {
+                                switch (obj_type) {
+                                    case H5O_TYPE_GROUP:
+                                        break;
+
+                                    case H5O_TYPE_DATASET:
+                                        if (h5str_region_dataset(ENVONLY, out_str, ref_vp, expand_data) < 0)
+                                            CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                        break;
+
+                                    case H5O_TYPE_NAMED_DATATYPE:
+                                        break;
+
+                                    case H5O_TYPE_MAP:
+                                    case H5O_TYPE_UNKNOWN:
+                                    case H5O_TYPE_NTYPES:
+                                    default:
+                                        break;
+                                } /* end switch */
+                            }
+                            else
+                                H5_ASSERTION_ERROR(ENVONLY, "h5str_sprintf: H5R_OBJECT2 failed");
+                            break;
+                        case H5R_DATASET_REGION2:
+                            if (h5str_region_dataset(ENVONLY, out_str, ref_vp, expand_data) < 0)
+                                CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                            break;
+                        case H5R_ATTR:
+                            if ((new_obj_id = H5Ropen_attr(ref_vp, H5P_DEFAULT, H5P_DEFAULT)) >= 0) {
+                                if (h5str_dump_region_attribute(ENVONLY, out_str, new_obj_id) < 0)
+                                    CHECK_JNI_EXCEPTION(ENVONLY, JNI_FALSE);
+                                if (H5Aclose(new_obj_id) < 0)
+                                    H5_LIBRARY_ERROR(ENVONLY);
+                            }
+                            break;
+                        case H5R_BADTYPE:
+                        case H5R_MAXTYPE:
+                        default:
+                            break;
+                    } /* end switch */
+                }
+
+                if (H5Rdestroy(ref_vp) < 0)
+                    H5_LIBRARY_ERROR(ENVONLY);
+            }
 
             break;
         }
@@ -1761,7 +1914,7 @@ h5str_is_zero(const void *_mem, size_t size)
  *    Negative value: error occurred
  *-------------------------------------------------------------------------
  */
-static htri_t
+htri_t
 h5str_detect_vlen(hid_t tid)
 {
     htri_t ret = FAIL;
@@ -3118,29 +3271,65 @@ done:
     return ret_value;
 }
 
+/*-------------------------------------------------------------------------
+ * Function: H5Tdetect_variable_str
+ *
+ * Purpose:  Recursive check for variable length string of a datatype.
+ *
+ * Return:   TRUE : type contains any variable length string
+ *           FALSE : type doesn't contain any variable length string
+ *           Negative value: failed
+ *-------------------------------------------------------------------------
+ */
 htri_t
 H5Tdetect_variable_str(hid_t tid)
 {
-    htri_t ret_val = 0;
-
-    if (H5Tget_class(tid) == H5T_COMPOUND) {
-        unsigned i;
-        unsigned nm = (unsigned)H5Tget_nmembers(tid);
-        for (i = 0; i < nm; i++) {
-            htri_t status = 0;
-            hid_t  mtid   = 0;
-            if ((mtid = H5Tget_member_type(tid, i)) < 0)
-                return FAIL; /* exit immediately on error */
-            if ((status = H5Tdetect_variable_str(mtid)) < 0)
-                return status; /* exit immediately on error */
-            ret_val |= status;
+    H5T_class_t tclass = -1;
+    htri_t      ret    = FALSE;
+
+    ret = H5Tis_variable_str(tid);
+    if ((ret == TRUE) || (ret < 0))
+        goto done;
+
+    tclass = H5Tget_class(tid);
+    if (tclass == H5T_ARRAY || tclass == H5T_VLEN) {
+        hid_t btid = H5Tget_super(tid);
+
+        if (btid < 0) {
+            ret = (htri_t)btid;
+            goto done;
+        }
+        ret = H5Tdetect_variable_str(btid);
+        if ((ret == TRUE) || (ret < 0)) {
+            H5Tclose(btid);
+            goto done;
+        }
+    }
+    else if (tclass == H5T_COMPOUND) {
+        unsigned nmembs;
+        int      snmembs = H5Tget_nmembers(tid);
+        unsigned u;
+
+        if (snmembs < 0) {
+            ret = FAIL;
+            goto done;
+        }
+        nmembs = (unsigned)snmembs;
+
+        for (u = 0; u < nmembs; u++) {
+            hid_t mtid = H5Tget_member_type(tid, u);
+
+            ret = H5Tdetect_variable_str(mtid);
+            if ((ret == TRUE) || (ret < 0)) {
+                H5Tclose(mtid);
+                goto done;
+            }
             H5Tclose(mtid);
-        } /* end for */
-    }     /* end if */
-    else
-        ret_val = H5Tis_variable_str(tid);
+        }
+    }
 
-    return ret_val;
+done:
+    return ret;
 } /* end H5Tdetect_variable_str */
 
 static int
diff --git a/java/src/jni/h5util.h b/java/src/jni/h5util.h
index 6c568e1..3146c06 100644
--- a/java/src/jni/h5util.h
+++ b/java/src/jni/h5util.h
@@ -39,8 +39,10 @@ extern void   h5str_new(h5str_t *str, size_t len);
 extern void   h5str_free(h5str_t *str);
 extern void   h5str_resize(h5str_t *str, size_t new_len);
 extern char * h5str_append(h5str_t *str, const char *cstr);
+extern htri_t h5str_detect_vlen(hid_t tid);
 extern size_t h5str_convert(JNIEnv *env, char **in_str, hid_t container, hid_t tid, void *out_buf,
                             size_t out_buf_offset);
+extern int    h5str_sprint_old_reference(JNIEnv *env, h5str_t *out_str, hid_t region_obj, void *ref_buf);
 extern int    h5str_sprint_reference(JNIEnv *env, h5str_t *out_str, void *ref_p);
 extern size_t h5str_sprintf(JNIEnv *env, h5str_t *out_str, hid_t container, hid_t tid, void *in_buf,
                             int expand_data);
diff --git a/java/src/jni/nativeData.c b/java/src/jni/nativeData.c
index 9e63f4f..ac9168b 100644
--- a/java/src/jni/nativeData.c
+++ b/java/src/jni/nativeData.c
@@ -46,8 +46,7 @@ extern "C" {
 
 /* returns int [] */
 JNIEXPORT jintArray JNICALL
-Java_hdf_hdf5lib_HDFNativeData_byteToInt___3B(JNIEnv *env, jclass clss,
-                                              jbyteArray bdata) /* IN: array of bytes */
+Java_hdf_hdf5lib_HDFNativeData_byteToInt___3B(JNIEnv *env, jclass clss, jbyteArray bdata)
 {
     jintArray rarray = NULL;
     jboolean  bb;
diff --git a/java/test/TestH5A.java b/java/test/TestH5A.java
index fed13ce..96ce5b5 100644
--- a/java/test/TestH5A.java
+++ b/java/test/TestH5A.java
@@ -20,6 +20,8 @@ import static org.junit.Assert.fail;
 
 import java.io.File;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 
 import hdf.hdf5lib.H5;
 import hdf.hdf5lib.HDF5Constants;
@@ -637,9 +639,8 @@ public class TestH5A {
             attr_info = H5.H5Aget_info_by_idx(H5did, ".", HDF5Constants.H5_INDEX_CRT_ORDER,
                                               HDF5Constants.H5_ITER_INC, 0, lapl_id);
             assertNotNull(attr_info);
-            assertTrue("Corder ",
-                       attr_info.corder ==
-                           0); // should equal 0 as this is the order of 1st attribute created.
+            assertTrue("Corder ", attr_info.corder ==
+                                      0); // should equal 0 as this is the order of 1st attribute created.
             assertEquals(attr_info.data_size, H5.H5Aget_storage_size(attr_id));
 
             // Verify info for 2nd attribute, in increasing creation order
@@ -653,33 +654,29 @@ public class TestH5A {
             attr_info = H5.H5Aget_info_by_idx(H5did, ".", HDF5Constants.H5_INDEX_CRT_ORDER,
                                               HDF5Constants.H5_ITER_DEC, 0, lapl_id);
             assertNotNull(attr_info);
-            assertTrue("Corder",
-                       attr_info.corder ==
-                           1); // should equal 1 as this is the order of 2nd attribute created.
+            assertTrue("Corder", attr_info.corder ==
+                                     1); // should equal 1 as this is the order of 2nd attribute created.
 
             // verify info for 1st attribute, in decreasing creation order
             attr_info = H5.H5Aget_info_by_idx(H5did, ".", HDF5Constants.H5_INDEX_CRT_ORDER,
                                               HDF5Constants.H5_ITER_DEC, 1, lapl_id);
             assertNotNull(attr_info);
-            assertTrue("Corder",
-                       attr_info.corder ==
-                           0); // should equal 0 as this is the order of 1st attribute created.
+            assertTrue("Corder", attr_info.corder ==
+                                     0); // should equal 0 as this is the order of 1st attribute created.
 
             // verify info for 1st attribute, in increasing name order
             attr_info = H5.H5Aget_info_by_idx(H5did, ".", HDF5Constants.H5_INDEX_NAME,
                                               HDF5Constants.H5_ITER_INC, 1, lapl_id);
             assertNotNull(attr_info);
-            assertTrue("Corder",
-                       attr_info.corder ==
-                           0); // should equal 0 as this is the order of 1st attribute created.
+            assertTrue("Corder", attr_info.corder ==
+                                     0); // should equal 0 as this is the order of 1st attribute created.
 
             // verify info for 2nd attribute, in decreasing name order
             attr_info = H5.H5Aget_info_by_idx(H5did, ".", HDF5Constants.H5_INDEX_NAME,
                                               HDF5Constants.H5_ITER_DEC, 1, lapl_id);
             assertNotNull(attr_info);
-            assertTrue("Corder",
-                       attr_info.corder ==
-                           1); // should equal 1 as this is the order of 2nd attribute created.
+            assertTrue("Corder", attr_info.corder ==
+                                     1); // should equal 1 as this is the order of 2nd attribute created.
         }
         catch (Throwable err) {
             err.printStackTrace();
@@ -1075,7 +1072,7 @@ public class TestH5A {
                                    HDF5Constants.H5P_DEFAULT);
             assertTrue("testH5Awrite_readVL: ", attr_id >= 0);
 
-            H5.H5AwriteVL(attr_id, atype_id, str_data);
+            H5.H5Awrite_VLStrings(attr_id, atype_id, str_data);
 
             H5.H5Fflush(H5fid, HDF5Constants.H5F_SCOPE_LOCAL);
 
@@ -1087,7 +1084,7 @@ public class TestH5A {
                 strs[j] = "";
             }
             try {
-                H5.H5AreadVL(attr_id, atype_id, strs);
+                H5.H5Aread_VLStrings(attr_id, atype_id, strs);
             }
             catch (Exception ex) {
                 ex.printStackTrace();
@@ -1162,12 +1159,12 @@ public class TestH5A {
                 fail("H5.H5Acreate: " + err);
             }
 
-            /* Close the property list, and get the attribute's property list */
+            // Close the property list, and get the attribute's property list
             H5.H5Pclose(plist_id);
             plist_id = H5.H5Aget_create_plist(attribute_id);
             assertTrue(plist_id > 0);
 
-            /* Get the character encoding and ensure that it is the default (ASCII) */
+            // Get the character encoding and ensure that it is the default (ASCII)
             try {
                 char_encoding = H5.H5Pget_char_encoding(plist_id);
             }
@@ -1371,4 +1368,212 @@ public class TestH5A {
                 }
         }
     }
+
+    @Test
+    public void testH5AVLwr()
+    {
+        String attr_int_name = "VLIntdata";
+        String attr_dbl_name = "VLDbldata";
+        long attr_int_id     = HDF5Constants.H5I_INVALID_HID;
+        long attr_dbl_id     = HDF5Constants.H5I_INVALID_HID;
+        long atype_int_id    = HDF5Constants.H5I_INVALID_HID;
+        long atype_dbl_id    = HDF5Constants.H5I_INVALID_HID;
+        long aspace_id       = HDF5Constants.H5I_INVALID_HID;
+        long[] dims          = {4};
+        long lsize           = 1;
+
+        ArrayList[] vl_int_data = new ArrayList[4];
+        ArrayList[] vl_dbl_data = new ArrayList[4];
+        try {
+            // Write Integer data
+            vl_int_data[0]  = new ArrayList<Integer>(Arrays.asList(1));
+            vl_int_data[1]  = new ArrayList<Integer>(Arrays.asList(2, 3));
+            vl_int_data[2]  = new ArrayList<Integer>(Arrays.asList(4, 5, 6));
+            vl_int_data[3]  = new ArrayList<Integer>(Arrays.asList(7, 8, 9, 10));
+            Class dataClass = vl_int_data.getClass();
+            assertTrue("testH5AVLwr.getClass: " + dataClass, dataClass.isArray());
+
+            try {
+                atype_int_id = H5.H5Tvlen_create(HDF5Constants.H5T_STD_U32LE);
+                assertTrue("testH5AVLwr.H5Tvlen_create: ", atype_int_id >= 0);
+            }
+            catch (Exception err) {
+                if (atype_int_id > 0)
+                    try {
+                        H5.H5Tclose(atype_int_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5AVLwr: " + err);
+            }
+
+            try {
+                aspace_id = H5.H5Screate_simple(1, dims, null);
+                assertTrue(aspace_id > 0);
+                attr_int_id = H5.H5Acreate(H5did, attr_int_name, atype_int_id, aspace_id,
+                                           HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+                assertTrue("testH5AVLwr: ", attr_int_id >= 0);
+
+                H5.H5AwriteVL(attr_int_id, atype_int_id, vl_int_data);
+            }
+            catch (Exception err) {
+                if (attr_int_id > 0)
+                    try {
+                        H5.H5Aclose(attr_int_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                if (atype_int_id > 0)
+                    try {
+                        H5.H5Tclose(atype_int_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5AVLwr: " + err);
+            }
+            finally {
+                if (aspace_id > 0)
+                    try {
+                        H5.H5Sclose(aspace_id);
+                    }
+                    catch (Exception ex) {
+                    }
+            }
+
+            // Write Double data
+            vl_dbl_data[0] = new ArrayList<Double>(Arrays.asList(1.1));
+            vl_dbl_data[1] = new ArrayList<Double>(Arrays.asList(2.2, 3.3));
+            vl_dbl_data[2] = new ArrayList<Double>(Arrays.asList(4.4, 5.5, 6.6));
+            vl_dbl_data[3] = new ArrayList<Double>(Arrays.asList(7.7, 8.8, 9.9, 10.0));
+            dataClass      = vl_dbl_data.getClass();
+            assertTrue("testH5AVLwr.getClass: " + dataClass, dataClass.isArray());
+
+            try {
+                atype_dbl_id = H5.H5Tvlen_create(HDF5Constants.H5T_NATIVE_DOUBLE);
+                assertTrue("testH5AVLwr.H5Tvlen_create: ", atype_dbl_id >= 0);
+            }
+            catch (Exception err) {
+                if (atype_dbl_id > 0)
+                    try {
+                        H5.H5Tclose(atype_dbl_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5AVLwr: " + err);
+            }
+
+            try {
+                aspace_id = H5.H5Screate_simple(1, dims, null);
+                assertTrue(aspace_id > 0);
+                attr_dbl_id = H5.H5Acreate(H5did, attr_dbl_name, atype_dbl_id, aspace_id,
+                                           HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+                assertTrue("testH5AVLwr: ", attr_dbl_id >= 0);
+
+                H5.H5AwriteVL(attr_dbl_id, atype_dbl_id, vl_dbl_data);
+            }
+            catch (Exception err) {
+                if (attr_dbl_id > 0)
+                    try {
+                        H5.H5Aclose(attr_dbl_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                if (atype_dbl_id > 0)
+                    try {
+                        H5.H5Tclose(atype_dbl_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5AVLwr: " + err);
+            }
+            finally {
+                if (aspace_id > 0)
+                    try {
+                        H5.H5Sclose(aspace_id);
+                    }
+                    catch (Exception ex) {
+                    }
+            }
+
+            H5.H5Fflush(H5fid, HDF5Constants.H5F_SCOPE_LOCAL);
+
+            for (int j = 0; j < dims.length; j++) {
+                lsize *= dims[j];
+            }
+
+            // Read Integer data
+            ArrayList[] vl_readbuf = new ArrayList[4];
+            for (int j = 0; j < lsize; j++)
+                vl_readbuf[j] = new ArrayList<Integer>();
+
+            try {
+                H5.H5AreadVL(attr_int_id, atype_int_id, vl_readbuf);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace();
+            }
+            assertTrue("testH5AVLwr:" + vl_readbuf[0].get(0),
+                       vl_int_data[0].get(0).equals(vl_readbuf[0].get(0)));
+            assertTrue("testH5AVLwr:" + vl_readbuf[1].get(0),
+                       vl_int_data[1].get(0).equals(vl_readbuf[1].get(0)));
+            assertTrue("testH5AVLwr:" + vl_readbuf[2].get(0),
+                       vl_int_data[2].get(0).equals(vl_readbuf[2].get(0)));
+            assertTrue("testH5AVLwr:" + vl_readbuf[3].get(0),
+                       vl_int_data[3].get(0).equals(vl_readbuf[3].get(0)));
+
+            // Read Double data
+            vl_readbuf = new ArrayList[4];
+            for (int j = 0; j < lsize; j++)
+                vl_readbuf[j] = new ArrayList<Double>();
+
+            try {
+                H5.H5AreadVL(attr_dbl_id, atype_dbl_id, vl_readbuf);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace();
+            }
+            assertTrue("testH5AVLwr:" + vl_readbuf[0].get(0),
+                       vl_dbl_data[0].get(0).equals(vl_readbuf[0].get(0)));
+            assertTrue("testH5AVLwr:" + vl_readbuf[1].get(0),
+                       vl_dbl_data[1].get(0).equals(vl_readbuf[1].get(0)));
+            assertTrue("testH5AVLwr:" + vl_readbuf[2].get(0),
+                       vl_dbl_data[2].get(0).equals(vl_readbuf[2].get(0)));
+            assertTrue("testH5AVLwr:" + vl_readbuf[3].get(0),
+                       vl_dbl_data[3].get(0).equals(vl_readbuf[3].get(0)));
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("H5.testH5AVLwr: " + err);
+        }
+        finally {
+            if (attr_dbl_id > 0)
+                try {
+                    H5.H5Aclose(attr_dbl_id);
+                }
+                catch (Exception ex) {
+                }
+            if (attr_int_id > 0)
+                try {
+                    H5.H5Aclose(attr_int_id);
+                }
+                catch (Exception ex) {
+                }
+            if (atype_dbl_id > 0)
+                try {
+                    H5.H5Tclose(atype_dbl_id);
+                }
+                catch (Exception ex) {
+                }
+            if (atype_int_id > 0)
+                try {
+                    H5.H5Tclose(atype_int_id);
+                }
+                catch (Exception ex) {
+                }
+        }
+    }
 }
diff --git a/java/test/TestH5D.java b/java/test/TestH5D.java
index 4bab1a9..f7e5702 100644
--- a/java/test/TestH5D.java
+++ b/java/test/TestH5D.java
@@ -17,6 +17,9 @@ import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 
 import hdf.hdf5lib.H5;
 import hdf.hdf5lib.HDF5Constants;
@@ -961,8 +964,8 @@ public class TestH5D {
         assertTrue("H5Dvlen_get_buf_size " + vl_size + " == " + str_data_bytes, vl_size == str_data_bytes);
     }
 
-    @Test(expected = IllegalArgumentException.class)
-    public void testH5Dvlen_read_invalid_buffer() throws Throwable
+    @Test
+    public void testH5Dvlen_read_default_buffer() throws Throwable
     {
         String[] str_data = {"Parting", "is such", "sweet", "sorrow.", "Testing",  "one", "two",   "three.",
                              "Dog,",    "man's",   "best",  "friend.", "Diamonds", "are", "a",     "girls!",
@@ -1013,4 +1016,218 @@ public class TestH5D {
             assertTrue("testH5Dvlen_write_read " + str_wdata[v] + " == " + str_rdata[v],
                        str_wdata[v] == str_wdata[v]);
     }
+
+    @Test
+    public void testH5DVLwr()
+    {
+        String dset_int_name = "VLIntdata";
+        String dset_dbl_name = "VLDbldata";
+        long dset_int_id     = HDF5Constants.H5I_INVALID_HID;
+        long dset_dbl_id     = HDF5Constants.H5I_INVALID_HID;
+        long dtype_int_id    = HDF5Constants.H5I_INVALID_HID;
+        long dtype_dbl_id    = HDF5Constants.H5I_INVALID_HID;
+        long dspace_id       = HDF5Constants.H5I_INVALID_HID;
+        long[] dims          = {4};
+        long lsize           = 1;
+
+        ArrayList[] vl_int_data = new ArrayList[4];
+        ArrayList[] vl_dbl_data = new ArrayList[4];
+        try {
+            // Write Integer data
+            vl_int_data[0]  = new ArrayList<Integer>(Arrays.asList(1));
+            vl_int_data[1]  = new ArrayList<Integer>(Arrays.asList(2, 3));
+            vl_int_data[2]  = new ArrayList<Integer>(Arrays.asList(4, 5, 6));
+            vl_int_data[3]  = new ArrayList<Integer>(Arrays.asList(7, 8, 9, 10));
+            Class dataClass = vl_int_data.getClass();
+            assertTrue("testH5DVLwr.getClass: " + dataClass, dataClass.isArray());
+
+            try {
+                dtype_int_id = H5.H5Tvlen_create(HDF5Constants.H5T_STD_U32LE);
+                assertTrue("testH5DVLwr.H5Tvlen_create: ", dtype_int_id >= 0);
+            }
+            catch (Exception err) {
+                if (dtype_int_id > 0)
+                    try {
+                        H5.H5Tclose(dtype_int_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5DVLwr: " + err);
+            }
+
+            try {
+                dspace_id = H5.H5Screate_simple(1, dims, null);
+                assertTrue(dspace_id > 0);
+                dset_int_id =
+                    H5.H5Dcreate(H5fid, dset_int_name, dtype_int_id, dspace_id, HDF5Constants.H5P_DEFAULT,
+                                 HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+                assertTrue("testH5DVLwr: ", dset_int_id >= 0);
+
+                H5.H5DwriteVL(dset_int_id, dtype_int_id, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
+                              HDF5Constants.H5P_DEFAULT, vl_int_data);
+            }
+            catch (Exception err) {
+                if (dset_int_id > 0)
+                    try {
+                        H5.H5Dclose(dset_int_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                if (dtype_int_id > 0)
+                    try {
+                        H5.H5Tclose(dtype_int_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5DVLwr: " + err);
+            }
+            finally {
+                if (dspace_id > 0)
+                    try {
+                        H5.H5Sclose(dspace_id);
+                    }
+                    catch (Exception ex) {
+                    }
+            }
+
+            // Write Double data
+            vl_dbl_data[0] = new ArrayList<Double>(Arrays.asList(1.1));
+            vl_dbl_data[1] = new ArrayList<Double>(Arrays.asList(2.2, 3.3));
+            vl_dbl_data[2] = new ArrayList<Double>(Arrays.asList(4.4, 5.5, 6.6));
+            vl_dbl_data[3] = new ArrayList<Double>(Arrays.asList(7.7, 8.8, 9.9, 10.0));
+            dataClass      = vl_dbl_data.getClass();
+            assertTrue("testH5DVLwr.getClass: " + dataClass, dataClass.isArray());
+
+            try {
+                dtype_dbl_id = H5.H5Tvlen_create(HDF5Constants.H5T_NATIVE_DOUBLE);
+                assertTrue("testH5DVLwr.H5Tvlen_create: ", dtype_dbl_id >= 0);
+            }
+            catch (Exception err) {
+                if (dtype_dbl_id > 0)
+                    try {
+                        H5.H5Tclose(dtype_dbl_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5DVLwr: " + err);
+            }
+
+            try {
+                dspace_id = H5.H5Screate_simple(1, dims, null);
+                assertTrue(dspace_id > 0);
+                dset_dbl_id =
+                    H5.H5Dcreate(H5fid, dset_dbl_name, dtype_dbl_id, dspace_id, HDF5Constants.H5P_DEFAULT,
+                                 HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+                assertTrue("testH5DVLwr: ", dset_dbl_id >= 0);
+
+                H5.H5DwriteVL(dset_dbl_id, dtype_dbl_id, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
+                              HDF5Constants.H5P_DEFAULT, vl_dbl_data);
+            }
+            catch (Exception err) {
+                if (dset_dbl_id > 0)
+                    try {
+                        H5.H5Dclose(dset_dbl_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                if (dtype_dbl_id > 0)
+                    try {
+                        H5.H5Tclose(dtype_dbl_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5DVLwr: " + err);
+            }
+            finally {
+                if (dspace_id > 0)
+                    try {
+                        H5.H5Sclose(dspace_id);
+                    }
+                    catch (Exception ex) {
+                    }
+            }
+
+            H5.H5Fflush(H5fid, HDF5Constants.H5F_SCOPE_LOCAL);
+
+            for (int j = 0; j < dims.length; j++) {
+                lsize *= dims[j];
+            }
+
+            // Read Integer data
+            ArrayList[] vl_readbuf = new ArrayList[4];
+            for (int j = 0; j < lsize; j++)
+                vl_readbuf[j] = new ArrayList<Integer>();
+
+            try {
+                H5.H5DreadVL(dset_int_id, dtype_int_id, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
+                             HDF5Constants.H5P_DEFAULT, vl_readbuf);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace();
+            }
+            assertTrue("testH5DVLwr:" + vl_readbuf[0].get(0),
+                       vl_int_data[0].get(0).equals(vl_readbuf[0].get(0)));
+            assertTrue("testH5DVLwr:" + vl_readbuf[1].get(0),
+                       vl_int_data[1].get(0).equals(vl_readbuf[1].get(0)));
+            assertTrue("testH5DVLwr:" + vl_readbuf[2].get(0),
+                       vl_int_data[2].get(0).equals(vl_readbuf[2].get(0)));
+            assertTrue("testH5DVLwr:" + vl_readbuf[3].get(0),
+                       vl_int_data[3].get(0).equals(vl_readbuf[3].get(0)));
+
+            // Read Double data
+            vl_readbuf = new ArrayList[4];
+            for (int j = 0; j < lsize; j++)
+                vl_readbuf[j] = new ArrayList<Double>();
+
+            try {
+                H5.H5DreadVL(dset_dbl_id, dtype_dbl_id, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
+                             HDF5Constants.H5P_DEFAULT, vl_readbuf);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace();
+            }
+            assertTrue("testH5DVLwr:" + vl_readbuf[0].get(0),
+                       vl_dbl_data[0].get(0).equals(vl_readbuf[0].get(0)));
+            assertTrue("testH5DVLwr:" + vl_readbuf[1].get(0),
+                       vl_dbl_data[1].get(0).equals(vl_readbuf[1].get(0)));
+            assertTrue("testH5DVLwr:" + vl_readbuf[2].get(0),
+                       vl_dbl_data[2].get(0).equals(vl_readbuf[2].get(0)));
+            assertTrue("testH5DVLwr:" + vl_readbuf[3].get(0),
+                       vl_dbl_data[3].get(0).equals(vl_readbuf[3].get(0)));
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("H5.testH5DVLwr: " + err);
+        }
+        finally {
+            if (dset_dbl_id > 0)
+                try {
+                    H5.H5Dclose(dset_dbl_id);
+                }
+                catch (Exception ex) {
+                }
+            if (dset_int_id > 0)
+                try {
+                    H5.H5Dclose(dset_int_id);
+                }
+                catch (Exception ex) {
+                }
+            if (dtype_dbl_id > 0)
+                try {
+                    H5.H5Tclose(dtype_dbl_id);
+                }
+                catch (Exception ex) {
+                }
+            if (dtype_int_id > 0)
+                try {
+                    H5.H5Tclose(dtype_int_id);
+                }
+                catch (Exception ex) {
+                }
+        }
+    }
 }
diff --git a/java/test/TestH5R.java b/java/test/TestH5R.java
index 4e610bc..dd8634b 100644
--- a/java/test/TestH5R.java
+++ b/java/test/TestH5R.java
@@ -19,6 +19,9 @@ import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 
 import hdf.hdf5lib.H5;
 import hdf.hdf5lib.HDF5Constants;
@@ -528,4 +531,470 @@ public class TestH5R {
         byte[] ref = null;
         H5.H5Rget_attr_name(ref);
     }
+
+    @Test
+    public void testH5RVLattr_ref()
+    {
+        String attr_obj_name = "VLObjRefdata";
+        String attr_reg_name = "VLRegRefdata";
+        long attr_obj_id     = HDF5Constants.H5I_INVALID_HID;
+        long attr_reg_id     = HDF5Constants.H5I_INVALID_HID;
+        long atype_obj_id    = HDF5Constants.H5I_INVALID_HID;
+        long atype_reg_id    = HDF5Constants.H5I_INVALID_HID;
+        long aspace_id       = HDF5Constants.H5I_INVALID_HID;
+        long[] dims          = {4};
+        long lsize           = 1;
+        byte[] ref1          = null;
+        byte[] ref2          = null;
+        byte[] ref3          = null;
+        byte[] ref4          = null;
+
+        try {
+            // Create reference on dataset
+            ref1 = H5.H5Rcreate(H5fid, "/dset", HDF5Constants.H5R_DATASET_REGION, H5dsid);
+            assertNotNull(ref1);
+            ref2 = H5.H5Rcreate(H5gid, "dset2", HDF5Constants.H5R_DATASET_REGION, H5dsid);
+            assertNotNull(ref2);
+            ref3 = H5.H5Rcreate(H5gid, "/dset", HDF5Constants.H5R_OBJECT, -1);
+            assertNotNull(ref3);
+
+            // Create reference on group
+            ref4 = H5.H5Rcreate(H5gid, "/Group1", HDF5Constants.H5R_OBJECT, -1);
+            assertNotNull(ref3);
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("testH5RVLattr_ref: " + err);
+        }
+
+        ArrayList[] vl_obj_data = new ArrayList[4];
+        ArrayList[] vl_reg_data = new ArrayList[4];
+        try {
+            // Write Object Reference data
+            vl_obj_data[0]  = new ArrayList<byte[]>(Arrays.asList(ref3));
+            vl_obj_data[1]  = new ArrayList<byte[]>(Arrays.asList(ref3, ref4));
+            vl_obj_data[2]  = new ArrayList<byte[]>(Arrays.asList(ref3, ref3, ref3));
+            vl_obj_data[3]  = new ArrayList<byte[]>(Arrays.asList(ref4, ref4, ref4, ref4));
+            Class dataClass = vl_obj_data.getClass();
+            assertTrue("testH5RVLattr_ref.getClass: " + dataClass, dataClass.isArray());
+
+            try {
+                atype_obj_id = H5.H5Tvlen_create(HDF5Constants.H5T_STD_REF_OBJ);
+                assertTrue("testH5RVLattr_ref.H5Tvlen_create: ", atype_obj_id >= 0);
+            }
+            catch (Exception err) {
+                if (atype_obj_id > 0)
+                    try {
+                        H5.H5Tclose(atype_obj_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5RVLattr_ref: " + err);
+            }
+
+            try {
+                aspace_id = H5.H5Screate_simple(1, dims, null);
+                assertTrue(aspace_id > 0);
+                attr_obj_id = H5.H5Acreate(H5did, attr_obj_name, atype_obj_id, aspace_id,
+                                           HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+                assertTrue("testH5RVLattr_ref: ", attr_obj_id >= 0);
+
+                H5.H5AwriteVL(attr_obj_id, atype_obj_id, vl_obj_data);
+            }
+            catch (Exception err) {
+                if (attr_obj_id > 0)
+                    try {
+                        H5.H5Aclose(attr_obj_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                if (atype_obj_id > 0)
+                    try {
+                        H5.H5Tclose(atype_obj_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5RVLattr_ref: " + err);
+            }
+            finally {
+                if (aspace_id > 0)
+                    try {
+                        H5.H5Sclose(aspace_id);
+                    }
+                    catch (Exception ex) {
+                    }
+            }
+
+            // Write Region Reference data
+            vl_reg_data[0] = new ArrayList<byte[]>(Arrays.asList(ref1));
+            vl_reg_data[1] = new ArrayList<byte[]>(Arrays.asList(ref1, ref2));
+            vl_reg_data[2] = new ArrayList<byte[]>(Arrays.asList(ref1, ref1, ref1));
+            vl_reg_data[3] = new ArrayList<byte[]>(Arrays.asList(ref2, ref2, ref2, ref2));
+            dataClass      = vl_reg_data.getClass();
+            assertTrue("testH5RVLattr_ref.getClass: " + dataClass, dataClass.isArray());
+
+            try {
+                atype_reg_id = H5.H5Tvlen_create(HDF5Constants.H5T_STD_REF_DSETREG);
+                assertTrue("testH5RVLattr_ref.H5Tvlen_create: ", atype_reg_id >= 0);
+            }
+            catch (Exception err) {
+                if (atype_reg_id > 0)
+                    try {
+                        H5.H5Tclose(atype_reg_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5RVLattr_ref: " + err);
+            }
+
+            try {
+                aspace_id = H5.H5Screate_simple(1, dims, null);
+                assertTrue(aspace_id > 0);
+                attr_reg_id = H5.H5Acreate(H5did, attr_reg_name, atype_reg_id, aspace_id,
+                                           HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+                assertTrue("testH5RVLattr_ref: ", attr_reg_id >= 0);
+
+                H5.H5AwriteVL(attr_reg_id, atype_reg_id, vl_reg_data);
+            }
+            catch (Exception err) {
+                if (attr_reg_id > 0)
+                    try {
+                        H5.H5Aclose(attr_reg_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                if (atype_reg_id > 0)
+                    try {
+                        H5.H5Tclose(atype_reg_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5RVLattr_ref: " + err);
+            }
+            finally {
+                if (aspace_id > 0)
+                    try {
+                        H5.H5Sclose(aspace_id);
+                    }
+                    catch (Exception ex) {
+                    }
+            }
+
+            H5.H5Fflush(H5fid, HDF5Constants.H5F_SCOPE_LOCAL);
+
+            for (int j = 0; j < dims.length; j++) {
+                lsize *= dims[j];
+            }
+
+            // Read Object Reference data
+            ArrayList[] vl_readbuf = new ArrayList[4];
+            for (int j = 0; j < lsize; j++)
+                vl_readbuf[j] = new ArrayList<byte[]>();
+
+            try {
+                H5.H5AreadVL(attr_obj_id, atype_obj_id, vl_readbuf);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace();
+            }
+            assertTrue("testH5RVLattr_ref:" + ((byte[])vl_readbuf[0].get(0))[0],
+                       ((byte[])vl_obj_data[0].get(0))[0] == ((byte[])vl_readbuf[0].get(0))[0]);
+            assertTrue("testH5RVLattr_ref:" + ((byte[])vl_readbuf[1].get(0))[0],
+                       ((byte[])vl_obj_data[1].get(0))[0] == ((byte[])vl_readbuf[1].get(0))[0]);
+            assertTrue("testH5RVLattr_ref:" + ((byte[])vl_readbuf[2].get(0))[0],
+                       ((byte[])vl_obj_data[2].get(0))[0] == ((byte[])vl_readbuf[2].get(0))[0]);
+            assertTrue("testH5RVLattr_ref:" + ((byte[])vl_readbuf[3].get(0))[0],
+                       ((byte[])vl_obj_data[3].get(0))[0] == ((byte[])vl_readbuf[3].get(0))[0]);
+
+            // Read Region Reference data
+            vl_readbuf = new ArrayList[4];
+            for (int j = 0; j < lsize; j++)
+                vl_readbuf[j] = new ArrayList<byte[]>();
+
+            try {
+                H5.H5AreadVL(attr_reg_id, atype_reg_id, vl_readbuf);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace();
+            }
+            assertTrue("testH5RVLattr_ref:" + ((byte[])vl_readbuf[0].get(0))[0],
+                       ((byte[])vl_reg_data[0].get(0))[0] == ((byte[])vl_readbuf[0].get(0))[0]);
+            assertTrue("testH5RVLattr_ref:" + ((byte[])vl_readbuf[1].get(0))[0],
+                       ((byte[])vl_reg_data[1].get(0))[0] == ((byte[])vl_readbuf[1].get(0))[0]);
+            assertTrue("testH5RVLattr_ref:" + ((byte[])vl_readbuf[2].get(0))[0],
+                       ((byte[])vl_reg_data[2].get(0))[0] == ((byte[])vl_readbuf[2].get(0))[0]);
+            assertTrue("testH5RVLattr_ref:" + ((byte[])vl_readbuf[3].get(0))[0],
+                       ((byte[])vl_reg_data[3].get(0))[0] == ((byte[])vl_readbuf[3].get(0))[0]);
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("H5.testH5RVLattr_ref: " + err);
+        }
+        finally {
+            if (attr_reg_id > 0)
+                try {
+                    H5.H5Aclose(attr_reg_id);
+                }
+                catch (Exception ex) {
+                }
+            if (attr_obj_id > 0)
+                try {
+                    H5.H5Aclose(attr_obj_id);
+                }
+                catch (Exception ex) {
+                }
+            if (atype_reg_id > 0)
+                try {
+                    H5.H5Tclose(atype_reg_id);
+                }
+                catch (Exception ex) {
+                }
+            if (atype_obj_id > 0)
+                try {
+                    H5.H5Tclose(atype_obj_id);
+                }
+                catch (Exception ex) {
+                }
+        }
+    }
+
+    @Test
+    public void testH5RVLdset_ref()
+    {
+        String dset_obj_name = "VLObjRefdata";
+        String dset_reg_name = "VLRegRefdata";
+        long dset_obj_id     = HDF5Constants.H5I_INVALID_HID;
+        long dset_reg_id     = HDF5Constants.H5I_INVALID_HID;
+        long dtype_obj_id    = HDF5Constants.H5I_INVALID_HID;
+        long dtype_reg_id    = HDF5Constants.H5I_INVALID_HID;
+        long dspace_id       = HDF5Constants.H5I_INVALID_HID;
+        long[] dims          = {4};
+        long lsize           = 1;
+        byte[] ref1          = null;
+        byte[] ref2          = null;
+        byte[] ref3          = null;
+        byte[] ref4          = null;
+
+        try {
+            // Create reference on dataset
+            ref1 = H5.H5Rcreate(H5fid, "/dset", HDF5Constants.H5R_DATASET_REGION, H5dsid);
+            assertNotNull(ref1);
+            ref2 = H5.H5Rcreate(H5gid, "dset2", HDF5Constants.H5R_DATASET_REGION, H5dsid);
+            assertNotNull(ref2);
+            ref3 = H5.H5Rcreate(H5gid, "/dset", HDF5Constants.H5R_OBJECT, -1);
+            assertNotNull(ref3);
+
+            // Create reference on group
+            ref4 = H5.H5Rcreate(H5gid, "/Group1", HDF5Constants.H5R_OBJECT, -1);
+            assertNotNull(ref3);
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("testH5RVLattr_ref: " + err);
+        }
+
+        ArrayList[] vl_obj_data = new ArrayList[4];
+        ArrayList[] vl_reg_data = new ArrayList[4];
+        try {
+            // Write Object Reference data
+            vl_obj_data[0]  = new ArrayList<byte[]>(Arrays.asList(ref3));
+            vl_obj_data[1]  = new ArrayList<byte[]>(Arrays.asList(ref3, ref4));
+            vl_obj_data[2]  = new ArrayList<byte[]>(Arrays.asList(ref3, ref3, ref3));
+            vl_obj_data[3]  = new ArrayList<byte[]>(Arrays.asList(ref4, ref4, ref4, ref4));
+            Class dataClass = vl_obj_data.getClass();
+            assertTrue("testH5RVLdset_ref.getClass: " + dataClass, dataClass.isArray());
+
+            try {
+                dtype_obj_id = H5.H5Tvlen_create(HDF5Constants.H5T_STD_REF_OBJ);
+                assertTrue("testH5RVLdset_ref.H5Tvlen_create: ", dtype_obj_id >= 0);
+            }
+            catch (Exception err) {
+                if (dtype_obj_id > 0)
+                    try {
+                        H5.H5Tclose(dtype_obj_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5RVLdset_ref: " + err);
+            }
+
+            try {
+                dspace_id = H5.H5Screate_simple(1, dims, null);
+                assertTrue(dspace_id > 0);
+                dset_obj_id =
+                    H5.H5Dcreate(H5fid, dset_obj_name, dtype_obj_id, dspace_id, HDF5Constants.H5P_DEFAULT,
+                                 HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+                assertTrue("testH5RVLdset_ref: ", dset_obj_id >= 0);
+
+                H5.H5DwriteVL(dset_obj_id, dtype_obj_id, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
+                              HDF5Constants.H5P_DEFAULT, vl_obj_data);
+            }
+            catch (Exception err) {
+                if (dset_obj_id > 0)
+                    try {
+                        H5.H5Dclose(dset_obj_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                if (dtype_obj_id > 0)
+                    try {
+                        H5.H5Tclose(dtype_obj_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5RVLdset_ref: " + err);
+            }
+            finally {
+                if (dspace_id > 0)
+                    try {
+                        H5.H5Sclose(dspace_id);
+                    }
+                    catch (Exception ex) {
+                    }
+            }
+
+            // Write Region Reference data
+            vl_reg_data[0] = new ArrayList<byte[]>(Arrays.asList(ref1));
+            vl_reg_data[1] = new ArrayList<byte[]>(Arrays.asList(ref1, ref2));
+            vl_reg_data[2] = new ArrayList<byte[]>(Arrays.asList(ref1, ref1, ref1));
+            vl_reg_data[3] = new ArrayList<byte[]>(Arrays.asList(ref2, ref2, ref2, ref2));
+            dataClass      = vl_reg_data.getClass();
+            assertTrue("testH5RVLdset_ref.getClass: " + dataClass, dataClass.isArray());
+
+            try {
+                dtype_reg_id = H5.H5Tvlen_create(HDF5Constants.H5T_STD_REF_DSETREG);
+                assertTrue("testH5RVLdset_ref.H5Tvlen_create: ", dtype_reg_id >= 0);
+            }
+            catch (Exception err) {
+                if (dtype_reg_id > 0)
+                    try {
+                        H5.H5Tclose(dtype_reg_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5RVLdset_ref: " + err);
+            }
+
+            try {
+                dspace_id = H5.H5Screate_simple(1, dims, null);
+                assertTrue(dspace_id > 0);
+                dset_reg_id =
+                    H5.H5Dcreate(H5fid, dset_reg_name, dtype_reg_id, dspace_id, HDF5Constants.H5P_DEFAULT,
+                                 HDF5Constants.H5P_DEFAULT, HDF5Constants.H5P_DEFAULT);
+                assertTrue("testH5RVLdset_ref: ", dset_reg_id >= 0);
+
+                H5.H5DwriteVL(dset_reg_id, dtype_reg_id, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
+                              HDF5Constants.H5P_DEFAULT, vl_reg_data);
+            }
+            catch (Exception err) {
+                if (dset_reg_id > 0)
+                    try {
+                        H5.H5Dclose(dset_reg_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                if (dtype_reg_id > 0)
+                    try {
+                        H5.H5Tclose(dtype_reg_id);
+                    }
+                    catch (Exception ex) {
+                    }
+                err.printStackTrace();
+                fail("H5.testH5RVLdset_ref: " + err);
+            }
+            finally {
+                if (dspace_id > 0)
+                    try {
+                        H5.H5Sclose(dspace_id);
+                    }
+                    catch (Exception ex) {
+                    }
+            }
+
+            H5.H5Fflush(H5fid, HDF5Constants.H5F_SCOPE_LOCAL);
+
+            for (int j = 0; j < dims.length; j++) {
+                lsize *= dims[j];
+            }
+
+            // Read Object Reference data
+            ArrayList[] vl_readbuf = new ArrayList[4];
+            for (int j = 0; j < lsize; j++)
+                vl_readbuf[j] = new ArrayList<byte[]>();
+
+            try {
+                H5.H5DreadVL(dset_obj_id, dtype_obj_id, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
+                             HDF5Constants.H5P_DEFAULT, vl_readbuf);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace();
+            }
+            assertTrue("testH5RVLdset_ref:" + ((byte[])vl_readbuf[0].get(0))[0],
+                       ((byte[])vl_obj_data[0].get(0))[0] == ((byte[])vl_readbuf[0].get(0))[0]);
+            assertTrue("testH5RVLdset_ref:" + ((byte[])vl_readbuf[1].get(0))[0],
+                       ((byte[])vl_obj_data[1].get(0))[0] == ((byte[])vl_readbuf[1].get(0))[0]);
+            assertTrue("testH5RVLdset_ref:" + ((byte[])vl_readbuf[2].get(0))[0],
+                       ((byte[])vl_obj_data[2].get(0))[0] == ((byte[])vl_readbuf[2].get(0))[0]);
+            assertTrue("testH5RVLdset_ref:" + ((byte[])vl_readbuf[3].get(0))[0],
+                       ((byte[])vl_obj_data[3].get(0))[0] == ((byte[])vl_readbuf[3].get(0))[0]);
+
+            // Read Region Reference data
+            vl_readbuf = new ArrayList[4];
+            for (int j = 0; j < lsize; j++)
+                vl_readbuf[j] = new ArrayList<byte[]>();
+
+            try {
+                H5.H5DreadVL(dset_reg_id, dtype_reg_id, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL,
+                             HDF5Constants.H5P_DEFAULT, vl_readbuf);
+            }
+            catch (Exception ex) {
+                ex.printStackTrace();
+            }
+            assertTrue("testH5RVLdset_ref:" + ((byte[])vl_readbuf[0].get(0))[0],
+                       ((byte[])vl_reg_data[0].get(0))[0] == ((byte[])vl_readbuf[0].get(0))[0]);
+            assertTrue("testH5RVLdset_ref:" + ((byte[])vl_readbuf[1].get(0))[0],
+                       ((byte[])vl_reg_data[1].get(0))[0] == ((byte[])vl_readbuf[1].get(0))[0]);
+            assertTrue("testH5RVLdset_ref:" + ((byte[])vl_readbuf[2].get(0))[0],
+                       ((byte[])vl_reg_data[2].get(0))[0] == ((byte[])vl_readbuf[2].get(0))[0]);
+            assertTrue("testH5RVLdset_ref:" + ((byte[])vl_readbuf[3].get(0))[0],
+                       ((byte[])vl_reg_data[3].get(0))[0] == ((byte[])vl_readbuf[3].get(0))[0]);
+        }
+        catch (Throwable err) {
+            err.printStackTrace();
+            fail("H5.testH5RVLdset_ref: " + err);
+        }
+        finally {
+            if (dset_reg_id > 0)
+                try {
+                    H5.H5Dclose(dset_reg_id);
+                }
+                catch (Exception ex) {
+                }
+            if (dset_obj_id > 0)
+                try {
+                    H5.H5Dclose(dset_obj_id);
+                }
+                catch (Exception ex) {
+                }
+            if (dtype_reg_id > 0)
+                try {
+                    H5.H5Tclose(dtype_reg_id);
+                }
+                catch (Exception ex) {
+                }
+            if (dtype_obj_id > 0)
+                try {
+                    H5.H5Tclose(dtype_obj_id);
+                }
+                catch (Exception ex) {
+                }
+        }
+    }
 }
diff --git a/java/test/testfiles/JUnit-TestH5A.txt b/java/test/testfiles/JUnit-TestH5A.txt
index 2026d21..efdd4a2 100644
--- a/java/test/testfiles/JUnit-TestH5A.txt
+++ b/java/test/testfiles/JUnit-TestH5A.txt
@@ -6,6 +6,7 @@ JUnit version 4.11
 .testH5Aiterate
 .testH5Aopen_by_idx
 .testH5Aopen_invalidname
+.testH5AVLwr
 .testH5Aopen
 .testH5Aget_info_by_name
 .testH5Aget_create_plist
@@ -30,5 +31,5 @@ JUnit version 4.11
 
 Time:  XXXX
 
-OK (28 tests)
+OK (29 tests)
 
diff --git a/java/test/testfiles/JUnit-TestH5D.txt b/java/test/testfiles/JUnit-TestH5D.txt
index 987655b..288e6d0 100644
--- a/java/test/testfiles/JUnit-TestH5D.txt
+++ b/java/test/testfiles/JUnit-TestH5D.txt
@@ -4,6 +4,7 @@ JUnit version 4.11
 .testH5Dcreate
 .testH5Dget_offset
 .testH5Dget_type
+.testH5DVLwr
 .testH5Dfill
 .testH5Dopen
 .testH5Dcreate_anon
@@ -11,15 +12,15 @@ JUnit version 4.11
 .testH5Dget_storage_size_empty
 .testH5Diterate
 .testH5Dget_access_plist
-.testH5Dvlen_read_invalid_buffer
 .testH5Dvlen_get_buf_size
 .testH5Dget_space_closed
 .testH5Dget_space_status
 .testH5Dvlen_write_read
 .testH5Dget_space
 .testH5Dget_type_closed
+.testH5Dvlen_read_default_buffer
 
 Time:  XXXX
 
-OK (19 tests)
+OK (20 tests)
 
diff --git a/java/test/testfiles/JUnit-TestH5R.txt b/java/test/testfiles/JUnit-TestH5R.txt
index a96fbb4..2420d62 100644
--- a/java/test/testfiles/JUnit-TestH5R.txt
+++ b/java/test/testfiles/JUnit-TestH5R.txt
@@ -4,6 +4,8 @@ JUnit version 4.11
 .testH5Ropen_region_Nullref
 .testH5Requal_Nullref1
 .testH5Requal_Nullref2
+.testH5RVLdset_ref
+.testH5RVLattr_ref
 .testH5Rget_object
 .testH5Rget_obj_type3_Nullref
 .testH5Ropen_object_Nullref
@@ -24,5 +26,5 @@ JUnit version 4.11
 
 Time:  XXXX
 
-OK (22 tests)
+OK (24 tests)
 
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index 8fe0df8..0901366 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -72,12 +72,48 @@ New Features
 
     Java Library:
     -------------
-    -
+    - Added reference support to H5A and H5D read write vlen JNI functions.
+
+      Added the implementation to handle VL references as an Array of Lists
+      of byte arrays.
+
+      The JNI wrappers translate the Array of Lists to/from the hvl_t vlen
+      structures. The wrappers use the specified datatype arguments for the
+      List type translation, it is expected that the Java type is correct.
+
+      (ADB - 2022/07/11, HDFFV-11318)
+
+    - H5A and H5D read write vlen JNI functions were incorrect.
+
+      Corrected the vlen function implementations for the basic primitive types.
+      The VLStrings functions now correctly use the implementation that had been
+      the VL functions. (VLStrings functions did not have an implementation.)
+      The new VL functions implementation now expect an Array of Lists between
+      Java and the JNI wrapper. 
+
+      The JNI wrappers translate the Array of Lists to/from the hvl_t vlen
+      structures. The wrappers use the specified datatype arguments for the
+      List type translation, it is expected that the Java type is correct.
+
+      (ADB - 2022/07/07, HDFFV-11310)
+
+    - H5A and H5D read write JNI functions had flawed vlen datatype check.
+
+      Adapted tools function for JNI utils file. This reduced multiple calls
+      to a single check and variable. The variable can then be used to call 
+      the H5Treclaim function. Adjusted existing test and added new test.
+
+      (ADB - 2022/06/22)
 
 
     Tools:
     ------
-    -
+    - 1.10 References in containers were not displayed properly by h5dump.
+
+      Ported 1.10 tools display function to provide ability to inspect and
+      display 1.10 reference data. 
+
+      (ADB - 2022/06/22)
 
 
     High-Level APIs:
diff --git a/tools/lib/h5tools_str.c b/tools/lib/h5tools_str.c
index 4e8dcc1..22d6677 100644
--- a/tools/lib/h5tools_str.c
+++ b/tools/lib/h5tools_str.c
@@ -1052,7 +1052,7 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
 
                 H5TOOLS_DEBUG("H5T_ENUM");
                 if (H5Tenum_nameof(type, vp, enum_name, sizeof enum_name) >= 0)
-                    h5tools_str_append(str, h5tools_escape(enum_name, sizeof(enum_name)));
+                    h5tools_str_append(str, "%s", h5tools_escape(enum_name, sizeof(enum_name)));
                 else {
                     size_t i;
                     if (1 == nsize)
@@ -1181,10 +1181,49 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
                     else if (H5Tequal(type, H5T_STD_REF_DSETREG)) {
                         /* if(nsize == H5R_DSET_REG_REF_BUF_SIZE) */
                         H5TOOLS_DEBUG("H5T_REFERENCE:H5T_STD_REF_DSETREG");
+                        h5tools_str_append(str, H5_TOOLS_DATASET);
+                        h5tools_str_sprint_old_reference(str, container, vp);
                     }
                     else if (H5Tequal(type, H5T_STD_REF_OBJ)) {
                         /* if (nsize == H5R_OBJ_REF_BUF_SIZE) */
+                        /*
+                         * Object references -- show the type and OID of the referenced object.
+                         */
+                        H5O_info1_t oi;
+
                         H5TOOLS_DEBUG("H5T_REFERENCE:H5T_STD_REF_OBJ");
+                        obj = H5Rdereference2(container, H5P_DEFAULT, H5R_OBJECT, vp);
+                        H5Oget_info2(obj, &oi, H5O_INFO_BASIC);
+
+                        /* Print object type and close object */
+                        switch (oi.type) {
+                            case H5O_TYPE_GROUP:
+                                h5tools_str_append(str, H5_TOOLS_GROUP);
+                                break;
+
+                            case H5O_TYPE_DATASET:
+                                h5tools_str_append(str, H5_TOOLS_DATASET);
+                                break;
+
+                            case H5O_TYPE_NAMED_DATATYPE:
+                                h5tools_str_append(str, H5_TOOLS_DATATYPE);
+                                break;
+
+                            case H5O_TYPE_UNKNOWN:
+                            case H5O_TYPE_NTYPES:
+                            default:
+                                h5tools_str_append(str, "%u-", (unsigned)oi.type);
+                                break;
+                        } /* end switch */
+                        H5Oclose(obj);
+
+                        /* Print OID */
+                        if (info->obj_hidefileno)
+                            h5tools_str_append(str, info->obj_format, oi.addr);
+                        else
+                            h5tools_str_append(str, info->obj_format, oi.fileno, oi.addr);
+
+                        h5tools_str_sprint_old_reference(str, container, vp);
                     } /* end else if (H5Tequal(type, H5T_STD_REF_OBJ)) */
                 }
                 break;
@@ -1265,6 +1304,7 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
                 nelmts = ((hvl_t *)((void *)cp_vp))->len;
 
                 for (i = 0; i < nelmts; i++) {
+                    H5TOOLS_DEBUG("H5T_VLEN %d of %ld", i, nelmts);
                     if (i)
                         h5tools_str_append(str, "%s", OPT(info->vlen_sep, "," OPTIONAL_LINE_BREAK));
 
@@ -1326,6 +1366,48 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
 }
 
 /*-------------------------------------------------------------------------
+ * Function:    h5tools_str_sprint_old_reference
+ *
+ * Purpose: Object reference -- show the name of the old referenced object.
+ *
+ * Return:  Nothing
+ *-------------------------------------------------------------------------
+ */
+void
+h5tools_str_sprint_old_reference(h5tools_str_t *str, hid_t container, void *vp)
+{
+    hid_t obj    = H5I_INVALID_HID;
+    hid_t region = H5I_INVALID_HID;
+    char  ref_name[1024];
+
+    H5TOOLS_START_DEBUG(" ");
+
+    h5tools_str_append(str, " \"");
+    obj = H5Rdereference2(container, H5P_DEFAULT, H5R_DATASET_REGION, vp);
+    if (obj >= 0) {
+        region = H5Rget_region(container, H5R_DATASET_REGION, vp);
+        if (region >= 0) {
+            H5Rget_name(obj, H5R_DATASET_REGION, vp, (char *)ref_name, 1024);
+            h5tools_str_append(str, "%s", ref_name);
+
+            H5Sclose(region);
+        } /* end if (region >= 0) */
+        H5Dclose(obj);
+    } /* end if (obj >= 0) */
+    else {
+        obj = H5Rdereference2(container, H5P_DEFAULT, H5R_OBJECT, vp);
+        if (obj >= 0) {
+            H5Rget_name(obj, H5R_OBJECT, vp, (char *)ref_name, 1024);
+            h5tools_str_append(str, "%s", ref_name);
+            H5Dclose(obj);
+        }
+    }
+    h5tools_str_append(str, "\"");
+
+    H5TOOLS_ENDDEBUG(" ");
+}
+
+/*-------------------------------------------------------------------------
  * Function:    h5tools_str_sprint_reference
  *
  * Purpose: Object reference -- show the name of the referenced object.
@@ -1402,10 +1484,10 @@ h5tools_str_sprint_reference(h5tools_str_t *str, H5R_ref_t *ref_vp)
 static char *
 h5tools_escape(char *s /*in,out*/, size_t size)
 {
-    register size_t i;
-    const char *    escape;
-    char            octal[8];
-    size_t          n = HDstrlen(s);
+    size_t      i;
+    const char *escape;
+    char        octal[8];
+    size_t      n = HDstrlen(s);
 
     for (i = 0; i < n; i++) {
         switch (s[i]) {
diff --git a/tools/lib/h5tools_str.h b/tools/lib/h5tools_str.h
index eee87c9..15834bb 100644
--- a/tools/lib/h5tools_str.h
+++ b/tools/lib/h5tools_str.h
@@ -41,6 +41,7 @@ H5TOOLS_DLL void  h5tools_str_dump_space_slabs(h5tools_str_t *, hid_t, const h5t
                                                h5tools_context_t *ctx);
 H5TOOLS_DLL void  h5tools_str_dump_space_blocks(h5tools_str_t *, hid_t, const h5tool_format_t *);
 H5TOOLS_DLL void  h5tools_str_dump_space_points(h5tools_str_t *, hid_t, const h5tool_format_t *);
+H5TOOLS_DLL void  h5tools_str_sprint_old_reference(h5tools_str_t *str, hid_t container, void *vp);
 H5TOOLS_DLL void  h5tools_str_sprint_reference(h5tools_str_t *str, H5R_ref_t *vp);
 H5TOOLS_DLL char *h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t container,
                                      hid_t type, void *vp, h5tools_context_t *ctx);