Here you can get additional checks and filters useful for your development. For usage and configuration of standard checks and filters please refer to Checkstyle documentation. Currently this extra package contains just one filter that was used by plugin to filter out UI builder generated content. This filter is not related to the plugin directly so anyone can use it.
To use the this extras in you must download the package netbeans-checkstyle-extra-4.1.0.jar and add it to the Checkstyle classpath.
When this filter is configured Checkstyle ignores the blocks of code generated by the UI builder. In order to use it you have to configure FileContentsHolder module inside of the TreeWalker. Example follows.
<module name="Checker">
<module name="cz.sickboy.netbeans.checkstyle.extra.GeneratedUIFilter"/>
<module name="TreeWalker">
<module name="FileContentsHolder"/>
...
</module>
</module>