How to run .jar file with specific classpath

simply but not easy as I google many sites 'til I found this ...

$ java -cp [jarfilename].jar [MainClass]

MainClass is class that contain 'public static void main(String args[])' which entry point for this jar file

Many Thanks to http://samindaw.wordpress.com/2008/11/04/specifying-the-main-class-to-run-in-a-jar-file-from-command-line/