[java] Run jar file in command prompt

If you dont have an entry point defined in your manifest invoking java -jar foo.jar will not work.

Use this command if you dont have a manifest or to run a different main class than the one specified in the manifest:

java -cp foo.jar full.package.name.ClassName

See also instructions on how to create a manifest with an entry point: https://docs.oracle.com/javase/tutorial/deployment/jar/appman.html