How to fix the maven check style error
CheckStyle is a module of maven that check the style of the code for things like tabs instead of spaces. Netty is using this to prevent basic formatting mistakes.
If you are planning to contribute to Netty, you should NOT remove the plugin as it probably means your patch will never applied.
If you are just using to play with, you are free to remove that plugin as its only purpose is to verify the installation, and not to change things from the installation.
If you choose to keep it, you should look in the output log to see what the mistakes are it detected, to quickly fix the mistakes, see this answer by Matthew Farwell.
- Right click on the java file in Package Explorer or whatever, and select 'Apply Checkstyle Corrections'.
- Click on the error in the problems view, and select 'Quick fix'. This corrects the problem.
Skip the check style execution using
-Dcheckstyle.skip
Ex
mvn [YOUR_COMMAND] -Dcheckstyle.skip