How to Set Up Java JDK in GitHub Actions with setup-java

name: 'Usage of setup-java GitHub Action'
on:
push:
    branches:
        - main
jobs:
deploy:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v4
    - uses: actions/setup-java@v4
      with:
        java-version: '21'

setup-java

Set up your GitHub Actions workflow with a specific version of Java

What is setup-java?​

The setup-java GitHub Action is a versatile tool for automating Java and Scala project setups in our CI/CD workflows. Here’s how you can use this action to enhance your Java development and deployment processes.

Key Features of setup-java​

• Java Version Management: Automatically downloads and sets up specified versions of Java, supporting various distributions.
• Local Java Setup: Allows extracting and caching a custom version of Java from a local file.
• Build Tools Configuration: Configures environments for publishing with Apache Maven and Gradle.
• Security Configuration: Supports setting up GPG private keys for secure transactions.
• Error Handling: Registers problem matchers to easily identify errors in workflow logs.
• Dependency Management: Enhances performance by caching dependencies managed by Apache Maven, Gradle, and sbt.
• Maven Toolchains: Supports Maven Toolchains declarations for managing multiple JDK versions.

How to Cache Dependencies with Maven and Gradle in GitHub Actions​

Cache dependencies to speed up build times in Maven and Gradle:

- name: Cache Maven packages
  uses: actions/cache@v3
  with:
    path: ~/.m2
    key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
    restore-keys: |
      ${{ runner.os }}-maven-

- name: Cache Gradle packages
  uses: actions/cache@v3
  with:
    path: |
      ~/.gradle/caches
      ~/.gradle/wrapper
    key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}

How to Configure Publishing with Maven in GitHub Actions​

Configure the runner for publishing artifacts using Maven or Gradle:

- name: Setup Maven Central Repository
  run: mvn deploy

- name: Setup Gradle Publish
  run: gradle publish

How to Configure GPG Private Key in GitHub Actions​

Set up a GPG private key for signing artifacts securely:

- name: Import GPG Key
  uses: actions/setup-java@v5
  with:
    gpg-private-key: ${{ secrets.GPG_PRIVATE_KEY }}
    gpg-passphrase: ${{ secrets.GPG_PASSPHRASE }}

How to Register Problem Matchers for Java in GitHub Actions​

Automatically detect and log errors during builds:

- name: Setup problem matchers for Java
  uses: actions/setup-java@v5
  with:
    problem-matchers: 'java'