Hibernate ORM is a component/library providing Object/Relational Mapping (ORM) support to applications and other components/libraries. It is also provides an implementation of the JPA specification, which is the standardized Java specification for ORM. See Hibernate.org for additional information.

Resources

The build requires a Java 8 JDK as JAVA_HOME.

You will need git to obtain the source.

Hibernate uses Gradle as its build tool. See the Gradle Primer section below if you are new to Gradle.

Contributors should read the Contributing Guide.

See the guides for setting up IntelliJ or Eclipse as your development environment.

Check out the Getting Started section in CONTRIBUTING.md for getting started working on Hibernate source.

CI Builds

Hibernate makes use of Jenkins for its CI needs. The project is built continuous on each push to the upstream repository. Overall there are a few different jobs, all of which can be seen at http://ci.hibernate.org/view/ORM/

Gradle primer

This section describes some of the basics developers and contributors new to Gradle might need to know to get productive quickly. The Gradle documentation is very well done; 2 in particular that are indispensable:

• Gradle User Guide is a typical user guide in that it follows a topical approach to describing all of the capabilities of Gradle.
• Gradle DSL Guide is quite unique and excellent in quickly getting up to speed on certain aspects of Gradle.

Using the Gradle Wrapper

For contributors who do not otherwise use Gradle and do not want to install it, Gradle offers a very cool features called the wrapper. It lets you run Gradle builds without a previously installed Gradle distro in a zero-conf manner. Hibernate configures the Gradle wrapper for you. If you would rather use the wrapper and not install Gradle (or to make sure you use the version of Gradle intended for older builds) you would just use the command gradlew (or gradlew.bat) rather than gradle (or gradle.bat) in the following discussions.
Note that gradlew is only available in the project's root dir, so depending on your pwd you may need to adjust the path to gradlew as well.

Examples use the gradle syntax, but just swap gradlew (properly relative) for gradle if you wish to use the wrapper.

_Note that another reason to use gradlew is that it uses the exact version of Gradle that the build is defined to work with.

Executing Tasks

Gradle uses the concept of build tasks (equivalent to Ant targets or Maven phases/goals). You can get a list of available tasks via

gradle tasks

To execute a task across all modules, simply perform that task from the root directory. Gradle will visit each sub-project and execute that task if the sub-project defines it. To execute a task in a specific module you can either:

1. cd into that module directory and execute the task
2. name the "task path". For example, in order to run the tests for the hibernate-core module from the root directory you could say gradle hibernate-core:test

Common Java related tasks

• build - Assembles (jars) and tests this project
• buildDependents - Assembles and tests this project and all projects that depend on it. So think of running this in hibernate-core, Gradle would assemble and test hibernate-core as well as hibernate-envers (because envers depends on core)
• classes - Compiles the main classes
• testClasses - Compiles the test classes
• compile (Hibernate addition) - Performs all compilation tasks including staging resources from both main and test
• jar - Generates a jar archive with all the compiled classes
• test - Runs the tests
• publish - Think Maven deploy
• publishToMavenLocal - Installs the project jar to your local maven cache (aka ~/.m2/repository). Note that Gradle never uses this, but it can be useful for testing your build with other local Maven-based builds.
• eclipse - Generates an Eclipse project
• idea - Generates an IntelliJ/IDEA project (although the preferred approach is to use IntelliJ's Gradle import).
• clean - Cleans the build directory

Testing and databases

Testing against a specific database can be achieved in 2 different ways:

Using the "Matrix Testing Plugin" for Gradle.

Coming soon...

Using "profiles"

The Hibernate build defines a number of database testing "profiles" in databases.gradle. These profiles can be activated by name using the db build property which can be passed either as a JVM system prop (-D) or as a Gradle project property (-P). Examples below use the Gradle project property approach.

gradle clean build -Pdb=pgsql

To run a test from your IDE, you need to ensure the property expansions happen. Use the following command:

gradle clean compile -Pdb=pgsql

NOTE : If you are running tests against a JDBC driver that is not available via Maven central (generally due to license nonsense - Oracle, DB2, etc) be sure to add these drivers to your local Maven repo cache (~/.m2/repository) or (better) add it to a personal Maven repo server