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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* 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 COPYING file, which can be found at the root of the source code *
* distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases. *
* 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();
}
}
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