This guide shows you how to create a workflow that performs continuous integration (CI) for your Java project using the Gradle build system. The workflow you create will allow you to see when commits to a pull request cause build or test failures against your default branch; this approach can help ensure that your code is always healthy. You can extend your CI workflow to cache files and upload artifacts from a workflow run.
GitHub-hosted runners have a tools cache with pre-installed software, which includes Java Development Kits (JDKs) and Gradle. For a list of software and the pre-installed versions for JDK and Gradle, see "About GitHub-hosted runners".
You should be familiar with YAML and the syntax for GitHub Actions. For more information, see:
We recommend that you have a basic understanding of Java and the Gradle framework. For more information, see Getting Started in the Gradle documentation.
Using the Gradle starter workflow
GitHub provides a Gradle starter workflow that will work for most Gradle-based Java projects. For more information, see the Gradle starter workflow.
To get started quickly, you can choose the preconfigured Gradle starter workflow when you create a new workflow. For more information, see the "Quickstart for GitHub Actions."
You can also add this workflow manually by creating a new file in the
.github/workflows directory of your repository.
This workflow performs the following steps:
checkoutstep downloads a copy of your repository on the runner.
setup-javastep configures the Eclipse Temurin (Java) 17 JDK by Eclipse Adoptium.
- The "Validate Gradle wrapper" step validates the checksums of Gradle Wrapper JAR files present in the source tree.
- The "Build with Gradle" step does a build using the
gradle/gradle-build-actionaction provided by the Gradle organization on GitHub. The action takes care of invoking Gradle, collecting results, and caching state between jobs. For more information see
The default starter workflows are excellent starting points when creating your build and test workflow, and you can customize the starter workflow to suit your project’s needs.
Running on a different operating system
The starter workflow configures jobs to run on Linux, using the GitHub-hosted
ubuntu-latest runners. You can change the
runs-on key to run your jobs on a different operating system. For example, you can use the GitHub-hosted Windows runners.
Or, you can run on the GitHub-hosted macOS runners.
You can also run jobs in Docker containers, or you can provide a self-hosted runner that runs on your own infrastructure. For more information, see "Workflow syntax for GitHub Actions."
Specifying the JVM version and architecture
The starter workflow sets up the
PATH to contain OpenJDK 8 for the x64 platform. If you want to use a different version of Java, or target a different architecture (
x86), you can use the
setup-java action to choose a different Java runtime environment.
For example, to use version 11 of the JDK provided by Adoptium for the x64 platform, you can use the
setup-java action and configure the
architecture parameters to
steps: - uses: actions/checkout@v3 - name: Set up JDK 11 for x64 uses: actions/setup-java@v3 with: java-version: '11' distribution: 'adopt' architecture: x64
For more information, see the
Building and testing your code
You can use the same commands that you use locally to build and test your code.
The starter workflow will run the
build task by default. In the default Gradle configuration, this command will download dependencies, build classes, run tests, and package classes into their distributable format, for example, a JAR file.
If you use different commands to build your project, or you want to use a different task, you can specify those. For example, you may want to run the
package task that's configured in your ci.gradle file.
steps: - uses: actions/checkout@v3 - uses: actions/setup-java@v3 with: java-version: '17' distribution: 'temurin' - name: Validate Gradle wrapper uses: gradle/wrapper-validation-action@ccb4328a959376b642e027874838f60f8e596de3 - name: Run the Gradle package task uses: gradle/gradle-build-action@749f47bda3e44aa060e82d7b3ef7e40d953bd629 with: arguments: -b ci.gradle package
Your build dependencies can be cached to speed up your workflow runs. After a successful run, the
gradle/gradle-build-action caches important parts of the Gradle user home directory. In future jobs, the cache will be restored so that build scripts won't need to be recompiled and dependencies won't need to be downloaded from remote package repositories.
Caching is enabled by default when using the
gradle/gradle-build-action action. For more information, see
Packaging workflow data as artifacts
After your build has succeeded and your tests have passed, you may want to upload the resulting Java packages as a build artifact. This will store the built packages as part of the workflow run, and allow you to download them. Artifacts can help you test and debug pull requests in your local environment before they're merged. For more information, see "Storing workflow data as artifacts."
Gradle will usually create output files like JARs, EARs, or WARs in the
build/libs directory. You can upload the contents of that directory using the
steps: - uses: actions/checkout@v3 - uses: actions/setup-java@v3 with: java-version: '17' distribution: 'temurin' - name: Validate Gradle wrapper uses: gradle/wrapper-validation-action@ccb4328a959376b642e027874838f60f8e596de3 - name: Build with Gradle uses: gradle/gradle-build-action@749f47bda3e44aa060e82d7b3ef7e40d953bd629 with: arguments: build - uses: actions/upload-artifact@v3 with: name: Package path: build/libs