GitHub Action that checks Java code formatting using palantir-java-format native binary.

No Java, Maven, or Gradle required — downloads a native binary from Maven Central.

- uses: actions/checkout@v4

- uses: abashev/palantir-java-format-action@v1
  with:
    version: '2.89.0'

• Pull request — gets the list of changed files from the PR via gh pr diff
• Push — gets files changed between before and after commits in the push
• Other events — falls back to checking all .java files

• If all files are formatted correctly → passes ✅
• If any file has formatting issues → lists unformatted files and fails ❌

When the check fails, fix locally with:

palantir-java-format --palantir --replace <files>

on:
  pull_request:
  push:
    branches: [main]

jobs:
  format:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: abashev/palantir-java-format-action@v1
        with:
          version: '2.89.0'
          mode: ${{ github.event_name == 'push' && 'all' || 'changed' }}

You can also use the same formatter as a local git hook to catch formatting issues before they reach CI.

Copy pre-commit to your project:

cp pre-commit .git/hooks/pre-commit
# or with a custom hooks directory
cp pre-commit .githooks/pre-commit
git config core.hooksPath .githooks

The hook automatically downloads and caches the native binary on first run, then checks only staged .java files on each commit.

• Linux x86_64
• Linux aarch64
• macOS aarch64 (Apple Silicon)