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:

java [any other JVM options you need to give it] -jar foo.jar

You can run a JAR file from the command line like this:

java -jar myJARFile.jar