Overview

Checkstyle is a development tool to help programmers write Java code that adheres to a coding standard. It automates the process of checking Java code to spare humans of this boring (but important) task. This makes it ideal for projects that want to enforce a coding standard.

Checkstyle is highly configurable and can be made to support almost any coding standard. An example configuration file is supplied supporting the Sun Code Conventions. As well, other sample configuration files are supplied for other well known conventions.

A good example of a report that can be produced using Checkstyle and Maven can be seen here.

Features

Checkstyle can check many aspects of your source code. Historically it's main functionality has been to check code layout issues, but since the internal architecture was changed in version 3, more and more checks for other purposes have been added. Now Checkstyle provides checks that find class design problems, duplicate code, or bug patterns like double checked locking.

For a detailed list of available checks please refer to the Standard Checks page.

Download

The latest release of Checkstyle can be downloaded from the SourceForge download page.

If you want to live on the bleeding edge, you can checkout the current development code from Mercurial and compile yourself. Note, you will need to have the Mercurial EOL Extension enabled to ensure there are no issues with the line endings (this extension will make the files match the local operating system).

Related Tools

Checkstyle is most useful if you integrate it in your build process or your development environment. The distribution includes:

Additionally plug-ins are written by third-parties. Some of them are still based on the Checkstyle 2.4 release, although there have been many improvements since then. The known plug-ins are:

If you have written a plugin for other IDEs, please let us know, so we can provide a link here.