Intro

This directory contains instructions for building and using the library as well as the HDF5 history files.

HISTORY files

The HISTORY files contain the history of this branch of HDF5. They fall into three categories.

HISTORY-[VERSION 1]-[VERSION 2].txt

These files are created when we release a new major version and include all the changes that were made to the develop branch while creating a major release.

HISTORY-[VERSION].txt

This file contains the changes that were made to a maintenance branch since it split off from develop. It will also be found in the develop branch when experimental releases have been created.

CHANGELOG.md (formerly RELEASE.txt)

This is the changelog for the current version of the library.

For a MAJOR release (or in develop) this files lists all the changes since the last major version. For a MINOR release (or in a maintenance branch), this file lists all the changes since the last release in the maintenance branch.

Examples:

The file for HDF5 1.14.0 includes all the changes since HDF5 1.12.0
The file for HDF5 1.10.9 includes all the changes since HDF5 1.10.8
The file in develop includes all the changes since the last major release
The file in hdf5_1_14 includes all the changes since the last minor HDF5 1.14 release

Note that we make no effort to bring maintenance branch HISTORY files back to develop. If you want to compare, say, 1.10.4 with 1.12.3, you'd have to get the history files from those releases and compare them by hand.

Creating new releases

MAJOR release

If there were experimental releases, merge the experimental HISTORY file and the current CHANGELOG.md by category to create a separate, unified file that ignores the experimental releases. Don't check this in yet or clobber any existing HISTORY/RELEASE files, but put it someplace handy for use in later steps.
Create the new maintenance branch

In develop:

Create the new HISTORY-\[VERSION 1\]-\[VERSION 2\].txt file
- If there is an experimental HISTORY file, add CHANGELOG.md to the beginning of it and use that
- Otherwise, start with CHANGELOG.md
- Add the introduction boilerplate like in the other HISTORY files (TOC, etc.)
Delete any experimental HISTORY file
Clear out CHANGELOG.md

Note that we're KEEPING any experimental release history information in the HISTORY-\[VERSION 1\]-\[VERSION 2\].txt file, so do NOT use the merged file in the above steps!

In the new maintenance branch:

Create the new HISTORY-\[VERSION\].txt file
- If there is an experimental HISTORY file use the combined file you created earlier
- Otherwise, start with CHANGELOG.md
- Add the introduction boilerplate like in the other HISTORY files (TOC, etc.)
Delete any experimental HISTORY file
Clear out CHANGELOG.md
Create the new release branch

In the new release branch:

If there were experimental releases, use the combined file you created earlier as CHANGELOG.md
Otherwise the CHANGELOG.md will be used as-is

MINOR release

Create the release branch

In the maintenance branch:

Add the contents of CHANGELOG.md to the beginnnig of HISTORY-\[VERSION\].txt
Clear out CHANGELOG.md

EXPERIMENTAL release

Add the contents of CHANGELOG.md to the beginnnig of HISTORY-\[VERSION\].txt
Clear out CHANGELOG.md

INSTALL files

These files include instructions for building and installing HDF5 on various platforms.

USING files

These files document how to build HDF5 applications with an installed HDF5 library.

Java Examples Maven Integration

The HDF5 Java examples are now integrated with Maven deployment to provide complete example applications that work with HDF5 Java library Maven artifacts:

Maven Artifacts

HDF5 provides two Java implementation artifacts:

**org.hdfgroup:hdf5-java-ffm** - FFM (Foreign Function & Memory) implementation
- Default for Java 25+, modern native access via Project Panama
- Platform-specific JARs: linux-x86_64, windows-x86_64, macos-x86_64, macos-aarch64
**org.hdfgroup:hdf5-java-jni** - JNI (Java Native Interface) implementation
- Available for all Java versions (11+)
- Platform-specific JARs: linux-x86_64, windows-x86_64, macos-x86_64, macos-aarch64
**org.hdfgroup:hdf5-java-examples** - Complete collection of 62 Java examples
- Platform-independent JAR with educational examples
- Covers all major HDF5 functionality: datasets, datatypes, groups, tutorials
- Compatible with both FFM and JNI implementations

Both implementations use the same hdf.hdf5lib.* package structure for seamless migration.

FFM Test Suite

Running FFM Tests:

ctest -R "JUnitFFM" -V           # All FFM tests
ctest -R "JUnit-TestH5Affm" -V   # Attribute tests
ctest -R "JUnit-TestH5Pffm" -V   # Property tests
ctest -R "JUnit-TestH5Tffm" -V   # Datatype tests

Test Location: java/jtest/TestH5*ffm.java

Features

Dual Implementation Support: Choose FFM for modern Java or JNI for compatibility
Cross-Platform CI/CD: Automated testing across all supported platforms
Fork-Based Testing: Complete validation framework for testing on repository forks
Dynamic Repository Support: Workflows adapt automatically to any GitHub repository
Maven Integration: Seamless integration with standard Maven dependency management
Documentation: See HDF5Examples/JAVA/README-MAVEN.md for complete usage instructions

GitHub Packages Deployment

Using FFM implementation (Java 25+):

<dependency>
    <groupId>org.hdfgroup</groupId>
    <artifactId>hdf5-java-ffm</artifactId>
    <version>2.0.0-3</version>
    <classifier>linux-x86_64</classifier>
</dependency>

Using JNI implementation (Java 11+):

<dependency>
    <groupId>org.hdfgroup</groupId>
    <artifactId>hdf5-java-jni</artifactId>
    <version>2.0.0-3</version>
    <classifier>linux-x86_64</classifier>
</dependency>

The Java examples demonstrate proper usage of HDF5 Java bindings in real-world scenarios and serve as templates for developing HDF5-based Java applications.