Fix attribute Read

5 files changed, 453 insertions, 243 deletions

diff --git a/java/src/jni/h5aImp.c b/java/src/jni/h5aImp.c
index 26ec4fc..13f5207 100644
--- a/java/src/jni/h5aImp.c
+++ b/java/src/jni/h5aImp.c
@@ -49,6 +49,10 @@ extern jobject visit_callback;
 /* Local Prototypes */
 /********************/
 
+static herr_t H5AwriteVL_asstr (JNIEnv *env, hid_t attr_id, hid_t mem_id, jobjectArray buf);
+static herr_t H5AwriteVL_str (JNIEnv *env, hid_t attr_id, hid_t mem_id, jobjectArray buf);
+static herr_t H5AreadVL_asstr (JNIEnv *env, hid_t attr_id, hid_t mem_id, jobjectArray buf);
+static herr_t H5AreadVL_str (JNIEnv *env, hid_t attr_id, hid_t mem_id, jobjectArray buf);
 static herr_t H5A_iterate_cb(hid_t g_id, const char *name, const H5A_info_t *info, void *op_data);
 
 
@@ -178,7 +182,6 @@ Java_hdf_hdf5lib_H5_H5Aread
         } /* end if */
         else {
             status = H5Aread((hid_t)attr_id, (hid_t)mem_type_id, byteP);
-
             if (status < 0) {
                 ENVPTR->ReleaseByteArrayElements(ENVPAR buf, byteP, JNI_ABORT);
                 h5libraryError(env);
@@ -194,6 +197,323 @@ Java_hdf_hdf5lib_H5_H5Aread
 
 /*
  * Class:     hdf_hdf5lib_H5
+ * Method:    H5AwriteVL
+ * 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)
+{
+    herr_t  status = -1;
+    htri_t  isStr = 0;
+    htri_t  isVlenStr = 0;
+    htri_t  isComplex = 0;
+
+    if (buf == NULL) {
+        h5nullArgument(env, "H5AwriteVL:  buf is NULL");
+    } /* end if */
+    else {
+        isStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING);
+        if (H5Tget_class((hid_t)mem_type_id) == H5T_COMPOUND) {
+            unsigned i;
+            int nm = H5Tget_nmembers(mem_type_id);
+            for(i = 0; i <nm; i++) {
+                hid_t nested_tid = H5Tget_member_type((hid_t)mem_type_id, i);
+                isComplex = H5Tdetect_class((hid_t)nested_tid, H5T_COMPOUND) ||
+                            H5Tdetect_class((hid_t)nested_tid, H5T_VLEN);
+                H5Tclose(nested_tid);
+            }
+        }
+        else if (H5Tget_class((hid_t)mem_type_id) == H5T_VLEN) {
+            isVlenStr = 1; /* strings created by H5Tvlen_create(H5T_C_S1) */
+        }
+        if (isStr == 0 || isComplex>0 || isVlenStr) {
+            status = H5AwriteVL_asstr(env, (hid_t)attr_id, (hid_t)mem_type_id, buf);
+        }
+        else if (isStr > 0) {
+            status = H5AwriteVL_str(env, (hid_t)attr_id, (hid_t)mem_type_id, buf);
+        }
+    } /* end else */
+
+    return (jint)status;
+} /* end Java_hdf_hdf5lib_H5_H5Awrite_1VL */
+
+herr_t
+H5AwriteVL_str
+    (JNIEnv *env, hid_t aid, hid_t tid, jobjectArray buf)
+{
+    herr_t  status = -1;
+    char  **wdata;
+    jsize   size;
+    jint    i;
+
+    size = ENVPTR->GetArrayLength(ENVPAR (jarray) buf);
+
+    wdata = (char**)HDcalloc((size_t)size + 1, sizeof(char*));
+    if (!wdata) {
+        h5JNIFatalError(env, "H5AwriteVL_str:  cannot allocate buffer");
+    } /* end if */
+    else {
+        HDmemset(wdata, 0, (size_t)size * sizeof(char*));
+        for (i = 0; i < size; ++i) {
+            jstring obj = (jstring) ENVPTR->GetObjectArrayElement(ENVPAR (jobjectArray) buf, i);
+            if (obj != 0) {
+                jsize length = ENVPTR->GetStringUTFLength(ENVPAR obj);
+                const char *utf8 = ENVPTR->GetStringUTFChars(ENVPAR obj, 0);
+
+                if (utf8) {
+                    wdata[i] = (char*)HDmalloc((size_t)length + 1);
+                    if (wdata[i]) {
+                        HDmemset(wdata[i], 0, ((size_t)length + 1));
+                        HDstrncpy(wdata[i], utf8, (size_t)length);
+                    } /* end if */
+                } /* end if */
+
+                ENVPTR->ReleaseStringUTFChars(ENVPAR obj, utf8);
+                ENVPTR->DeleteLocalRef(ENVPAR obj);
+            } /* end if */
+        } /* end for (i = 0; i < size; ++i) */
+
+        status = H5Awrite((hid_t)aid, (hid_t)tid, wdata);
+
+        for (i = 0; i < size; i++) {
+            if(wdata[i]) {
+                HDfree(wdata[i]);
+            } /* end if */
+        } /* end for */
+        HDfree(wdata);
+
+        if (status < 0)
+            h5libraryError(env);
+    } /* end else */
+
+    return (jint)status;
+}
+
+herr_t
+H5AwriteVL_asstr
+    (JNIEnv *env, hid_t aid, hid_t tid, jobjectArray buf)
+{
+    char  **strs;
+    jstring jstr;
+    jint    i;
+    jint    n;
+    hid_t   sid;
+    hsize_t dims[H5S_MAX_RANK];
+    herr_t  status = -1;
+
+    n = ENVPTR->GetArrayLength(ENVPAR buf);
+    strs =(hvl_t*)HDcalloc((size_t)n, sizeof(hvl_t));
+
+    if (strs == NULL) {
+        h5JNIFatalError(env, "H5AwriteVL_asstr:  failed to allocate buff for read variable length strings");
+    } /* end if */
+    else {
+        status = H5Awrite(aid, tid, strs);
+
+        if (status < 0) {
+            dims[0] = (hsize_t)n;
+            sid = H5Screate_simple(1, dims, NULL);
+            H5Dvlen_reclaim(tid, sid, H5P_DEFAULT, strs);
+            H5Sclose(sid);
+            HDfree(strs);
+            h5JNIFatalError(env, "H5AwriteVL_str: failed to read variable length strings");
+        } /* end if */
+        else {
+            for (i=0; i < n; i++) {
+                jstr = ENVPTR->NewStringUTF(ENVPAR strs[i]);
+                ENVPTR->SetObjectArrayElement(ENVPAR buf, i, jstr);
+                H5free_memory (strs[i]);
+            } /* end for */
+
+            /*
+            for repeatedly reading a dataset with a large number of strs (e.g., 1,000,000 strings,
+            H5Dvlen_reclaim() may crash on Windows because the Java GC will not be able to collect
+            free space in time. Instead, use "H5free_memory(strs[i])" above to free individual strings
+            after it is done.
+            H5Dvlen_reclaim(tid, mem_sid, xfer_plist_id, strs);
+            */
+
+            HDfree(strs);
+        } /* end else */
+    } /* end else */
+
+    return status;
+} /* end H5AwriteVL_str */
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5AreadVL
+ * Signature: (JJJJJ[Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_H5_H5AreadVL
+    (JNIEnv *env, jclass clss, jlong attr_id, jlong mem_type_id, jobjectArray buf)
+{
+    herr_t  status = -1;
+    htri_t  isStr = 0;
+    htri_t  isVlenStr = 0;
+    htri_t  isComplex = 0;
+
+    if (buf == NULL) {
+        h5nullArgument(env, "H5AreadVL:  buf is NULL");
+    } /* end if */
+    else {
+        isStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING);
+        if (H5Tget_class((hid_t)mem_type_id) == H5T_COMPOUND) {
+            unsigned i;
+            int nm = H5Tget_nmembers(mem_type_id);
+            for(i = 0; i <nm; i++) {
+                hid_t nested_tid = H5Tget_member_type((hid_t)mem_type_id, i);
+                isComplex = H5Tdetect_class((hid_t)nested_tid, H5T_COMPOUND) ||
+                            H5Tdetect_class((hid_t)nested_tid, H5T_VLEN);
+                H5Tclose(nested_tid);
+            }
+        }
+        else if (H5Tget_class((hid_t)mem_type_id) == H5T_VLEN) {
+            isVlenStr = 1; /* strings created by H5Tvlen_create(H5T_C_S1) */
+        }
+        if (isStr == 0 || isComplex>0 || isVlenStr) {
+            status = H5AreadVL_asstr(env, (hid_t)attr_id, (hid_t)mem_type_id, buf);
+        }
+        else if (isStr > 0) {
+            status = H5AreadVL_str(env, (hid_t)attr_id, (hid_t)mem_type_id, buf);
+        }
+    } /* end else */
+
+    return (jint)status;
+} /* end Java_hdf_hdf5lib_H5_H5Aread_1VL */
+
+herr_t
+H5AreadVL_asstr
+    (JNIEnv *env, hid_t aid, hid_t tid, jobjectArray buf)
+{
+    jint    i;
+    jint    n;
+    hid_t   sid;
+    jstring jstr;
+    h5str_t h5str;
+    hvl_t  *rdata;
+    hsize_t dims[H5S_MAX_RANK];
+    size_t  size;
+    size_t  max_len = 0;
+    herr_t  status = -1;
+
+    /* Get size of string array */
+    n = ENVPTR->GetArrayLength(ENVPAR buf);
+    /* we will need to read n number of hvl_t structures */
+    rdata = (hvl_t*)HDcalloc((size_t)n, sizeof(hvl_t));
+    if (rdata == NULL) {
+        h5JNIFatalError(env, "H5AreadVL_asstr:  failed to allocate buff for read");
+    } /* end if */
+    else {
+        status = H5Aread(aid, tid, rdata);
+
+        if (status < 0) {
+            dims[0] = (hsize_t)n;
+            sid = H5Screate_simple(1, dims, NULL);
+            H5Dvlen_reclaim(tid, sid, H5P_DEFAULT, rdata);
+            H5Sclose(sid);
+            HDfree(rdata);
+            h5JNIFatalError(env, "H5AreadVL_asstr: failed to read data");
+        } /* end if */
+        else {
+            /* calculate the largest size of all the hvl_t structures read */
+            max_len = 1;
+            for (i=0; i < n; i++) {
+                if ((rdata + i)->len > max_len)
+                    max_len = (rdata + i)->len;
+            }
+
+            /* create one malloc to hold largest element */
+            size = H5Tget_size(tid) * max_len;
+            HDmemset(&h5str, 0, sizeof(h5str_t));
+            h5str_new(&h5str, 4 * size);
+
+            if (h5str.s == NULL) {
+                dims[0] = (hsize_t)n;
+                sid = H5Screate_simple(1, dims, NULL);
+                H5Dvlen_reclaim(tid, sid, H5P_DEFAULT, rdata);
+                H5Sclose(sid);
+                HDfree(rdata);
+                h5JNIFatalError(env, "H5AreadVL_asstr:  failed to allocate buf");
+            } /* end if */
+            else {
+                H5T_class_t tclass = H5Tget_class(tid);
+                /* convert each element to char string */
+                for (i=0; i < n; i++) {
+                    h5str.s[0] = '\0';
+                    h5str_vlsprintf(&h5str, aid, tid, rdata+i, 0);
+                    jstr = ENVPTR->NewStringUTF(ENVPAR h5str.s);
+                    ENVPTR->SetObjectArrayElement(ENVPAR buf, i, jstr);
+                } /* end for */
+                h5str_free(&h5str);
+
+                dims[0] = (hsize_t)n;
+                sid = H5Screate_simple(1, dims, NULL);
+                H5Dvlen_reclaim(tid, sid, H5P_DEFAULT, rdata);
+                H5Sclose(sid);
+                HDfree(rdata);
+            } /* end else */
+        } /* end else */
+    } /* end else */
+
+    return status;
+}
+
+herr_t
+H5AreadVL_str
+    (JNIEnv *env, hid_t aid, hid_t tid, jobjectArray buf)
+{
+    char  **strs;
+    jstring jstr;
+    jint    i;
+    jint    n;
+    hid_t   sid;
+    hsize_t dims[H5S_MAX_RANK];
+    herr_t  status = -1;
+
+    n = ENVPTR->GetArrayLength(ENVPAR buf);
+    strs =(char**)HDcalloc((size_t)n, sizeof(char*));
+
+    if (strs == NULL) {
+        h5JNIFatalError(env, "H5AreadVL_str:  failed to allocate buff for read variable length strings");
+    } /* end if */
+    else {
+        status = H5Aread(aid, tid, strs);
+
+        if (status < 0) {
+            dims[0] = (hsize_t)n;
+            sid = H5Screate_simple(1, dims, NULL);
+            H5Dvlen_reclaim(tid, sid, H5P_DEFAULT, strs);
+            H5Sclose(sid);
+            HDfree(strs);
+            h5JNIFatalError(env, "H5AreadVL_str: failed to read variable length strings");
+        } /* end if */
+        else {
+            for (i=0; i < n; i++) {
+                jstr = ENVPTR->NewStringUTF(ENVPAR strs[i]);
+                ENVPTR->SetObjectArrayElement(ENVPAR buf, i, jstr);
+                H5free_memory (strs[i]);
+            } /* end for */
+
+            /*
+            for repeatedly reading a dataset with a large number of strs (e.g., 1,000,000 strings,
+            H5Dvlen_reclaim() may crash on Windows because the Java GC will not be able to collect
+            free space in time. Instead, use "H5free_memory(strs[i])" above to free individual strings
+            after it is done.
+            H5Dvlen_reclaim(tid, mem_sid, xfer_plist_id, strs);
+            */
+
+            HDfree(strs);
+        } /* end else */
+    } /* end else */
+
+    return status;
+} /* end H5AreadVL_str */
+
+/*
+ * Class:     hdf_hdf5lib_H5
  * Method:    H5Aget_space
  * Signature: (J)J
  */
diff --git a/java/src/jni/h5aImp.h b/java/src/jni/h5aImp.h
index 62769fd..f3758eb 100644
--- a/java/src/jni/h5aImp.h
+++ b/java/src/jni/h5aImp.h
@@ -69,6 +69,24 @@ Java_hdf_hdf5lib_H5_H5Aread
 
 /*
  * Class:     hdf_hdf5lib_H5
+ * Method:    H5AwriteVL
+ * Signature: (JJ[Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_H5_H5AwriteVL
+  (JNIEnv *, jclass, jlong, jlong, jobjectArray);
+
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5AreadVL
+ * Signature: (JJ[Ljava/lang/String;)I
+ */
+JNIEXPORT jint JNICALL
+Java_hdf_hdf5lib_H5_H5AreadVL
+  (JNIEnv *, jclass, jlong, jlong, jobjectArray);
+
+/*
+ * Class:     hdf_hdf5lib_H5
  * Method:    H5Aget_space
  * Signature: (J)J
  */
diff --git a/java/src/jni/h5dImp.c b/java/src/jni/h5dImp.c
index 184bc88..1d7b823 100644
--- a/java/src/jni/h5dImp.c
+++ b/java/src/jni/h5dImp.c
@@ -993,120 +993,6 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1double
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5DreadVL
- * Signature: (JJJJJ[Ljava/lang/String;)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)
-{
-    herr_t  status = -1;
-    htri_t  isStr = 0;
-    htri_t  isVlenStr = 0;
-    htri_t  isComplex = 0;
-
-    if (buf == NULL) {
-        h5nullArgument(env, "H5DreadVL:  buf is NULL");
-    } /* end if */
-    else {
-        isStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING);
-        if (H5Tget_class((hid_t)mem_type_id) == H5T_COMPOUND) {
-            unsigned i;
-            int nm = H5Tget_nmembers(mem_type_id);
-            for(i = 0; i <nm; i++) {
-                hid_t nested_tid = H5Tget_member_type((hid_t)mem_type_id, i);
-                isComplex = H5Tdetect_class((hid_t)nested_tid, H5T_COMPOUND) ||
-                            H5Tdetect_class((hid_t)nested_tid, H5T_VLEN);
-                H5Tclose(nested_tid);
-            }
-        }
-        else if (H5Tget_class((hid_t)mem_type_id) == H5T_VLEN) {
-            isVlenStr = 1; /* strings created by H5Tvlen_create( H5T_C_S1) */
-        }
-        if (isStr == 0 || isComplex>0 || isVlenStr) {
-            status = H5DreadVL_asstr(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);
-        }
-        else if (isStr > 0) {
-            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);
-        }
-    } /* end else */
-
-    return (jint)status;
-} /* end Java_hdf_hdf5lib_H5_H5Dread_1VL */
-
-herr_t
-H5DreadVL_asstr
-    (JNIEnv *env, hid_t did, hid_t tid, hid_t mem_sid, hid_t file_sid, hid_t xfer_plist_id, jobjectArray buf)
-{
-    jint    i;
-    jint    n;
-    jstring jstr;
-    h5str_t h5str;
-    hvl_t  *rdata;
-    size_t  size;
-    size_t  max_len = 0;
-    herr_t  status = -1;
-
-    /* Get size of string array */
-    n = ENVPTR->GetArrayLength(ENVPAR buf);
-    /* we will need to read n number of hvl_t structures */
-    rdata = (hvl_t*)HDcalloc((size_t)n, sizeof(hvl_t));
-    if (rdata == NULL) {
-        h5JNIFatalError(env, "H5DreadVL_notstr:  failed to allocate buff for read");
-    } /* end if */
-    else {
-        status = H5Dread(did, tid, mem_sid, file_sid, xfer_plist_id, rdata);
-
-        if (status < 0) {
-            H5Dvlen_reclaim(tid, mem_sid, xfer_plist_id, rdata);
-            HDfree(rdata);
-            h5JNIFatalError(env, "H5DreadVL_notstr: failed to read data");
-        } /* end if */
-        else {
-            /* calculate the largest size of all the hvl_t structures read */
-            max_len = 1;
-            for (i=0; i < n; i++) {
-                if ((rdata + i)->len > max_len)
-                    max_len = (rdata + i)->len;
-            }
-
-            /* create one malloc to hold largest element */
-            size = H5Tget_size(tid) * max_len;
-            HDmemset(&h5str, 0, sizeof(h5str_t));
-            h5str_new(&h5str, 4 * size);
-
-            if (h5str.s == NULL) {
-                H5Dvlen_reclaim(tid, mem_sid, xfer_plist_id, rdata);
-                HDfree(rdata);
-                h5JNIFatalError(env, "H5DreadVL_notstr:  failed to allocate buf");
-            } /* end if */
-            else {
-                H5T_class_t tclass = H5Tget_class(tid);
-                /* convert each element to char string */
-                for (i=0; i < n; i++) {
-                    h5str.s[0] = '\0';
-                    h5str_vlsprintf(&h5str, did, tid, rdata+i, 0);
-                    jstr = ENVPTR->NewStringUTF(ENVPAR h5str.s);
-                    ENVPTR->SetObjectArrayElement(ENVPAR buf, i, jstr);
-                } /* end for */
-                h5str_free(&h5str);
-
-                H5Dvlen_reclaim(tid, mem_sid, xfer_plist_id, rdata);
-                HDfree(rdata);
-            } /* end else */
-        } /* end else */
-    } /* end else */
-
-    return status;
-}
-
-/*
- * Class:     hdf_hdf5lib_H5
  * Method:    H5Dread_string
  * Signature: (JJJJJ[Ljava/lang/String;)I
  */
@@ -1242,6 +1128,120 @@ Java_hdf_hdf5lib_H5_H5Dwrite_1string
     return (jint)status;
 } /* end Java_hdf_hdf5lib_H5_H5Dwrite_1string */
 
+/*
+ * Class:     hdf_hdf5lib_H5
+ * Method:    H5DreadVL
+ * Signature: (JJJJJ[Ljava/lang/String;)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)
+{
+    herr_t  status = -1;
+    htri_t  isStr = 0;
+    htri_t  isVlenStr = 0;
+    htri_t  isComplex = 0;
+
+    if (buf == NULL) {
+        h5nullArgument(env, "H5DreadVL:  buf is NULL");
+    } /* end if */
+    else {
+        isStr = H5Tdetect_class((hid_t)mem_type_id, H5T_STRING);
+        if (H5Tget_class((hid_t)mem_type_id) == H5T_COMPOUND) {
+            unsigned i;
+            int nm = H5Tget_nmembers(mem_type_id);
+            for(i = 0; i <nm; i++) {
+                hid_t nested_tid = H5Tget_member_type((hid_t)mem_type_id, i);
+                isComplex = H5Tdetect_class((hid_t)nested_tid, H5T_COMPOUND) ||
+                            H5Tdetect_class((hid_t)nested_tid, H5T_VLEN);
+                H5Tclose(nested_tid);
+            }
+        }
+        else if (H5Tget_class((hid_t)mem_type_id) == H5T_VLEN) {
+            isVlenStr = 1; /* strings created by H5Tvlen_create(H5T_C_S1) */
+        }
+        if (isStr == 0 || isComplex>0 || isVlenStr) {
+            status = H5DreadVL_asstr(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);
+        }
+        else if (isStr > 0) {
+            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);
+        }
+    } /* end else */
+
+    return (jint)status;
+} /* end Java_hdf_hdf5lib_H5_H5Dread_1VL */
+
+herr_t
+H5DreadVL_asstr
+    (JNIEnv *env, hid_t did, hid_t tid, hid_t mem_sid, hid_t file_sid, hid_t xfer_plist_id, jobjectArray buf)
+{
+    jint    i;
+    jint    n;
+    jstring jstr;
+    h5str_t h5str;
+    hvl_t  *rdata;
+    size_t  size;
+    size_t  max_len = 0;
+    herr_t  status = -1;
+
+    /* Get size of string array */
+    n = ENVPTR->GetArrayLength(ENVPAR buf);
+    /* we will need to read n number of hvl_t structures */
+    rdata = (hvl_t*)HDcalloc((size_t)n, sizeof(hvl_t));
+    if (rdata == NULL) {
+        h5JNIFatalError(env, "H5DreadVL_notstr:  failed to allocate buff for read");
+    } /* end if */
+    else {
+        status = H5Dread(did, tid, mem_sid, file_sid, xfer_plist_id, rdata);
+
+        if (status < 0) {
+            H5Dvlen_reclaim(tid, mem_sid, xfer_plist_id, rdata);
+            HDfree(rdata);
+            h5JNIFatalError(env, "H5DreadVL_notstr: failed to read data");
+        } /* end if */
+        else {
+            /* calculate the largest size of all the hvl_t structures read */
+            max_len = 1;
+            for (i=0; i < n; i++) {
+                if ((rdata + i)->len > max_len)
+                    max_len = (rdata + i)->len;
+            }
+
+            /* create one malloc to hold largest element */
+            size = H5Tget_size(tid) * max_len;
+            HDmemset(&h5str, 0, sizeof(h5str_t));
+            h5str_new(&h5str, 4 * size);
+
+            if (h5str.s == NULL) {
+                H5Dvlen_reclaim(tid, mem_sid, xfer_plist_id, rdata);
+                HDfree(rdata);
+                h5JNIFatalError(env, "H5DreadVL_notstr:  failed to allocate buf");
+            } /* end if */
+            else {
+                H5T_class_t tclass = H5Tget_class(tid);
+                /* convert each element to char string */
+                for (i=0; i < n; i++) {
+                    h5str.s[0] = '\0';
+                    h5str_vlsprintf(&h5str, did, tid, rdata+i, 0);
+                    jstr = ENVPTR->NewStringUTF(ENVPAR h5str.s);
+                    ENVPTR->SetObjectArrayElement(ENVPAR buf, i, jstr);
+                } /* end for */
+                h5str_free(&h5str);
+
+                H5Dvlen_reclaim(tid, mem_sid, xfer_plist_id, rdata);
+                HDfree(rdata);
+            } /* end else */
+        } /* end else */
+    } /* end else */
+
+    return status;
+}
+
 /**
  *  Read VLEN data into array of arrays.
  *  Object[] buf contains VL arrays of data points
diff --git a/java/src/jni/h5util.c b/java/src/jni/h5util.c
index 5e2fe00..385bfc7 100644
--- a/java/src/jni/h5util.c
+++ b/java/src/jni/h5util.c
@@ -2002,116 +2002,6 @@ h5tools_dump_simple_data
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5AwriteVL
- * 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)
-{
-    herr_t  status = -1;
-    char  **wdata;
-    jsize   size;
-    jint    i;
-
-    size = ENVPTR->GetArrayLength(ENVPAR (jarray) buf);
-
-    wdata = (char**)HDcalloc((size_t)size + 1, sizeof(char*));
-    if (!wdata) {
-        h5JNIFatalError(env, "H5AwriteVL:  cannot allocate buffer");
-    } /* end if */
-    else {
-        HDmemset(wdata, 0, (size_t)size * sizeof(char*));
-        for (i = 0; i < size; ++i) {
-            jstring obj = (jstring) ENVPTR->GetObjectArrayElement(ENVPAR (jobjectArray) buf, i);
-            if (obj != 0) {
-                jsize length = ENVPTR->GetStringUTFLength(ENVPAR obj);
-                const char *utf8 = ENVPTR->GetStringUTFChars(ENVPAR obj, 0);
-
-                if (utf8) {
-                    wdata[i] = (char*)HDmalloc((size_t)length + 1);
-                    if (wdata[i]) {
-                        HDmemset(wdata[i], 0, ((size_t)length + 1));
-                        HDstrncpy(wdata[i], utf8, (size_t)length);
-                    } /* end if */
-                } /* end if */
-
-                ENVPTR->ReleaseStringUTFChars(ENVPAR obj, utf8);
-                ENVPTR->DeleteLocalRef(ENVPAR obj);
-            } /* end if */
-        } /* end for (i = 0; i < size; ++i) */
-
-        status = H5Awrite((hid_t)attr_id, (hid_t)mem_type_id, wdata);
-
-        for (i = 0; i < size; i++) {
-            if(wdata[i]) {
-                HDfree(wdata[i]);
-            } /* end if */
-        } /* end for */
-        HDfree(wdata);
-
-        if (status < 0)
-            h5libraryError(env);
-    } /* end else */
-
-    return (jint)status;
-} /* end Java_hdf_hdf5lib_H5_H5AwriteVL */
-
-/*
- * Class:     hdf_hdf5lib_H5
- * Method:    H5AreadVL
- * Signature: (JJ[Ljava/lang/String;)I
- */
-JNIEXPORT jint JNICALL
-Java_hdf_hdf5lib_H5_H5AreadVL
-    (JNIEnv *env, jclass clss, jlong attr_id, jlong mem_type_id, jobjectArray buf)
-{
-    herr_t  status = -1;
-    jstring jstr;
-    char  **strs;
-    int     i, n;
-    hid_t   sid;
-    hsize_t dims[H5S_MAX_RANK];
-
-    n = ENVPTR->GetArrayLength(ENVPAR buf);
-
-    strs =(char **)HDmalloc((size_t)n * sizeof(char *));
-    if (strs == NULL) {
-        h5JNIFatalError( env, "H5AreadVL:  failed to allocate buff for read variable length strings");
-    } /* end if */
-    else {
-        status = H5Aread(attr_id, mem_type_id, strs);
-        if (status < 0) {
-            dims[0] = (hsize_t)n;
-            sid = H5Screate_simple(1, dims, NULL);
-            H5Dvlen_reclaim(mem_type_id, sid, H5P_DEFAULT, strs);
-            H5Sclose(sid);
-            HDfree(strs);
-            h5JNIFatalError(env, "H5AreadVL: failed to read variable length strings");
-        } /* end if */
-        else {
-            for (i=0; i<n; i++) {
-                jstr = ENVPTR->NewStringUTF(ENVPAR strs[i]);
-                ENVPTR->SetObjectArrayElement(ENVPAR buf, i, jstr);
-                HDfree (strs[i]);
-            } /* end for */
-
-            /*
-                for repeatedly reading an attribute with a large number of strs (e.g., 1,000,000 strings,
-                H5Dvlen_reclaim() may crash on Windows because the Java GC will not be able to collect
-                free space in time. Instead, use "free(strs[i])" to free individual strings
-                after it is done.
-                H5Dvlen_reclaim(tid, sid, H5P_DEFAULT, strs);
-            */
-
-            HDfree(strs);
-        }  /* end else */
-    }  /* end else */
-    return status;
-} /* end Java_hdf_hdf5lib_H5_H5AreadVL */
-
-/*
- * Class:     hdf_hdf5lib_H5
  * Method:    H5AreadComplex
  * Signature: (JJ[Ljava/lang/String;)I
  */
diff --git a/java/src/jni/h5util.h b/java/src/jni/h5util.h
index 837f900..c6b41d2 100644
--- a/java/src/jni/h5util.h
+++ b/java/src/jni/h5util.h
@@ -48,24 +48,6 @@ extern int     h5str_dump_region_points_data(h5str_t *str, hid_t region, hid_t r
 
 /*
  * Class:     hdf_hdf5lib_H5
- * Method:    H5AwriteVL
- * Signature: (JJ[Ljava/lang/String;)I
- */
-JNIEXPORT jint JNICALL
-Java_hdf_hdf5lib_H5_H5AwriteVL
-  (JNIEnv *, jclass, jlong, jlong, jobjectArray);
-
-/*
- * Class:     hdf_hdf5lib_H5
- * Method:    H5AreadVL
- * Signature: (JJ[Ljava/lang/String;)I
- */
-JNIEXPORT jint JNICALL
-Java_hdf_hdf5lib_H5_H5AreadVL
-  (JNIEnv *, jclass, jlong, jlong, jobjectArray);
-
-/*
- * Class:     hdf_hdf5lib_H5
  * Method:    H5AreadComplex
  * Signature: (JJ[Ljava/lang/String;)I
  */