Subset dataset using Java HDF Object Package


I’m trying to write code that retrieves single values from a 4-D dataset using the Java HDF Object Package. My code is working well right up until I request the dimensions of the dataset to prepare to do the read. The calls to getDims(), getSelectedDims(), getStartDims(), and getStride() are all returning null. When I look at the file in HDFView, everything looks great.

Any ideas?


Java HDF Object Package from the HDFView 3.0.0 beta release on Windows 10, though I will be running this eventually on RHEL 7).


Hi Scott,

Please try the HDF-Java wrapper for HDF5 rather than the HDF-Java Object package. You should be
able to use the HDF-Java wrapper to subset a 4D dataset.

The HDF-Java Object package is limited in what it can do and targets common use-cases.

The HDF-Java wrapper for HDF5 is the native interface for Java HDF5 (JHI5), which “wraps around”
the HDF5 library. As of HDF5-1.10, HDF-Java is included with the HDF5-1.10 source code. See this
page for details:



Hi Barbara,

I’ve managed to get 1.10.2 built using CMake (whew) and then installed with the MSI. Now I’m getting a failure when I run.

Thread [main] (Suspended (exception ClassNotFoundException))
Launcher$AppClassLoader(ClassLoader).loadClass(String, boolean) line: not available
Launcher$AppClassLoader.loadClass(String, boolean) line: not available
Launcher$AppClassLoader(ClassLoader).loadClass(String) line: not available
H5.() line: 230
HDF5Constants.() line: 29
VolumetricReaderDriver.main(String[]) line: 12

In Eclipse:
I reference “C:\Program Files\HDF_Group\HDF5\1.10.2\lib\jarhdf5-1.10.2.jar.”
I have VM argument -Djava.library.path=“C:\Program Files\HDF_Group\HDF5\1.10.2\lib”
I set environment variable PATH=“C:\Program Files\HDF_Group\HDF5\1.10.2\lib”

The code:

import hdf.hdf5lib.H5;
import hdf.hdf5lib.HDF5Constants;
import hdf.hdf5lib.exceptions.HDF5LibraryException;

public class VolumetricReaderDriver {

public static void main(String[] args) {
	String volumetricFilePath = "C:\\Users\\scott\\Documents\\TEMP\\WxThreats\\SavedForTesting\\WindDirectionGPML\\WindDirectionGPML.h5";

	long h5File = -1;
	try {
		h5File = H5.H5Fopen(volumetricFilePath, HDF5Constants.H5F_ACC_RDONLY, HDF5Constants.H5P_DEFAULT);
	} catch (HDF5LibraryException | NullPointerException e) {
		// TODO Auto-generated catch block
	try {
	} catch (HDF5LibraryException e) {
		// TODO Auto-generated catch block


Any ideas what I’m missing?



Hi Scott,
I’m not exactly sure what the issue is. Can you check the file path and name to make sure it can find the file?


It seems I was missing an SLF4J library (found this a little while ago).