Jar executable

I created an app and created a .jar file with all the needed files. I can double click on it in the destination folder and it will run. I emailed it to a friend and when he tries to run it he gets a java error that says cannot find main class. How do I make an executable or install the .jar file so it can be executed by clicking on a shortcut or by clicking on the .jar file?

You need to create and executable jar. If you are using eclipse or NetBeans you can select an executable jar when exporting your project. Otherwise read this:Distributing your Application as an Executable JAR file

If you open the jar in an archive manager, try and open the the meta-inf and paste its context in here.

Regards Andy.