CommandPlugin interfaces provides a very simple
void doCommand( String args ) method. If you create a command Plugin using just the Interface then you will need to parse the arguments yourself.
If you use the
ArgsParsingCommandPlugin abstract class when creating your command plugin you get help when setting up and parsing command arguments. In this case you will uses the Java Simple Argument Parser† by Martian Software and the signature for the command execution method is
void doCommand( JSAPResult result ).
In this case the following references will be of use:
† Please note this page suggests the library isn't maintained. However, it was actually last updated on 11 April 2013