Plugin checkstyle

The Checkstyle plugin provides the functionality of Checkstyle to Loom. See the Checkstyle website for a comprehensive documentation of how to write custom configurations.

Loom uses Checkstyle version 8.2.


This plugin configures two products: checkstyleMainReport and checkstyleTestReport to provide reports for sources in src/main/java/ and src/test/java/ respectively.

These products are registered for the check goal (which is part of the build goal).

Minimum example

   - checkstyle

By default, the checkstyle plugin reads its configuration from config/checkstyle/checkstyle.xml. This directory/file has to be located in the project directory (or in each of your module directories for multi module projects). This default can be changed via the setting configLocation.

More advanced example

   - checkstyle
   checkstyle.configLocation: ../config/checkstyle/checkstyle.xml

In this example, a custom location ../config/checkstyle/checkstyle.xml will be used. This is handy if you want to have one checkstyle configurations for multiple modules.

Checkstyle itself comes with two built-in checks: /google_checks.xml and /sun_checks.xml (note the leading / for built-in check configurations). Both are part of the official Checkstyle package and are maintained by the Checkstyle Team.


Path to a file containing the Checkstyle configuration. By default, config/checkstyle/checkstyle.xml is used. The path is relative to the Loom module directory, so each module requires its own configuration. If you want a checkstyle configuration per project, you can set ../config/checkstyle/checkstyle.xml for example.


  • This plugin handles the cache configuration of Checkstyle automatically. Do not include a cacheFile property within your checkstyle.xml – otherwise Loom’s CLI options to disable caching (--no-cache or -n) wouldn’t work as expected.