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Diffstat (limited to 'java/examples/datasets/H5Ex_D_External.java')
| -rw-r--r-- | java/examples/datasets/H5Ex_D_External.java | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/java/examples/datasets/H5Ex_D_External.java b/java/examples/datasets/H5Ex_D_External.java new file mode 100644 index 0000000..5fdc696 --- /dev/null +++ b/java/examples/datasets/H5Ex_D_External.java @@ -0,0 +1,238 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * Copyright by The HDF Group. * + * Copyright by the Board of Trustees of the University of Illinois. * + * All rights reserved. * + * * + * This file is part of HDF5. The full HDF5 copyright notice, including * + * terms governing use, modification, and redistribution, is contained in * + * the files COPYING and Copyright.html. COPYING can be found at the root * + * of the source code distribution tree; Copyright.html can be found at the * + * root level of an installed copy of the electronic HDF5 document set and * + * is linked from the top-level documents page. It can also be found at * + * http://hdfgroup.org/HDF5/doc/Copyright.html. If you do not have * + * access to either file, you may request a copy from help@hdfgroup.org. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/************************************************************ + This example shows how to read and write data to an + external dataset. The program first writes integers to an + external dataset with dataspace dimensions of DIM_XxDIM_Y, + then closes the file. Next, it reopens the file, reads + back the data, and outputs the name of the external data + file and the data to the screen. + ************************************************************/ +package examples.datasets; + +import hdf.hdf5lib.H5; +import hdf.hdf5lib.HDF5Constants; + +public class H5Ex_D_External { + private static String FILENAME = "H5Ex_D_External.h5"; + private static String EXTERNALNAME = "H5Ex_D_External.data"; + private static String DATASETNAME = "DS1"; + private static final int DIM_X = 4; + private static final int DIM_Y = 7; + private static final int RANK = 2; + private static final int NAME_BUF_SIZE = 32; + + private static void writeExternal() { + long file_id = -1; + long dcpl_id = -1; + long filespace_id = -1; + long dataset_id = -1; + long[] dims = { DIM_X, DIM_Y }; + int[][] dset_data = new int[DIM_X][DIM_Y]; + + // Initialize the dataset. + for (int indx = 0; indx < DIM_X; indx++) + for (int jndx = 0; jndx < DIM_Y; jndx++) + dset_data[indx][jndx] = indx * jndx - jndx; + + // Create a new file using default properties. + try { + file_id = H5.H5Fcreate(FILENAME, HDF5Constants.H5F_ACC_TRUNC, HDF5Constants.H5P_DEFAULT, + HDF5Constants.H5P_DEFAULT); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Create dataspace. Setting maximum size to NULL sets the maximum + // size to be the current size. + try { + filespace_id = H5.H5Screate_simple(RANK, dims, null); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Create the dataset creation property list. + try { + dcpl_id = H5.H5Pcreate(HDF5Constants.H5P_DATASET_CREATE); + } + catch (Exception e) { + e.printStackTrace(); + } + + // set the external file. + try { + if (dcpl_id >= 0) + H5.H5Pset_external(dcpl_id, EXTERNALNAME, 0, HDF5Constants.H5F_UNLIMITED); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Create the HDF5Constants.dataset. + try { + if ((file_id >= 0) && (filespace_id >= 0) && (dcpl_id >= 0)) + dataset_id = H5.H5Dcreate(file_id, DATASETNAME, HDF5Constants.H5T_STD_I32LE, filespace_id, + HDF5Constants.H5P_DEFAULT, dcpl_id, HDF5Constants.H5P_DEFAULT); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Write the dataset. + try { + H5.H5Dwrite(dataset_id, HDF5Constants.H5T_NATIVE_INT, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL, + HDF5Constants.H5P_DEFAULT, dset_data); + } + catch (Exception e) { + e.printStackTrace(); + } + + // End access to the dataset and release resources used by it. + try { + if (dataset_id >= 0) + H5.H5Dclose(dataset_id); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Terminate access to the data space. + try { + if (filespace_id >= 0) + H5.H5Sclose(filespace_id); + } + catch (Exception e) { + e.printStackTrace(); + } + + try { + if (dcpl_id >= 0) + H5.H5Pclose(dcpl_id); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Close the file. + try { + if (file_id >= 0) + H5.H5Fclose(file_id); + } + catch (Exception e) { + e.printStackTrace(); + } + + } + + private static void readExternal() { + long file_id = -1; + long dcpl_id = -1; + long dataset_id = -1; + int[][] dset_data = new int[DIM_X][DIM_Y]; + String[] Xname = new String[1]; + + // Open file using the default properties. + try { + file_id = H5.H5Fopen(FILENAME, HDF5Constants.H5F_ACC_RDWR, HDF5Constants.H5P_DEFAULT); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Open dataset using the default properties. + try { + if (file_id >= 0) + dataset_id = H5.H5Dopen(file_id, DATASETNAME, HDF5Constants.H5P_DEFAULT); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Retrieve the dataset creation property list. + try { + if (dataset_id >= 0) + dcpl_id = H5.H5Dget_create_plist(dataset_id); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Retrieve and print the name of the external file. + long[] Xsize = new long[NAME_BUF_SIZE]; + try { + if (dcpl_id >= 0) + H5.H5Pget_external(dcpl_id, 0, Xsize.length, Xname, Xsize); + } + catch (Exception e) { + e.printStackTrace(); + } + System.out.println(DATASETNAME + " is stored in file: " + Xname[0]); + + // Read the data using the default properties. + try { + if (dataset_id >= 0) + H5.H5Dread(dataset_id, HDF5Constants.H5T_NATIVE_INT, HDF5Constants.H5S_ALL, HDF5Constants.H5S_ALL, + HDF5Constants.H5P_DEFAULT, dset_data); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Output the data to the screen. + System.out.println(DATASETNAME + ":"); + for (int indx = 0; indx < DIM_X; indx++) { + System.out.print(" [ "); + for (int jndx = 0; jndx < DIM_Y; jndx++) + System.out.print(dset_data[indx][jndx] + " "); + System.out.println("]"); + } + System.out.println(); + + // Close the dataset. + try { + if (dataset_id >= 0) + H5.H5Dclose(dataset_id); + } + catch (Exception e) { + e.printStackTrace(); + } + + try { + if (dcpl_id >= 0) + H5.H5Pclose(dcpl_id); + } + catch (Exception e) { + e.printStackTrace(); + } + + // Close the file. + try { + if (file_id >= 0) + H5.H5Fclose(file_id); + } + catch (Exception e) { + e.printStackTrace(); + } + } + + public static void main(String[] args) { + H5Ex_D_External.writeExternal(); + H5Ex_D_External.readExternal(); + } + +} |