How to make an executable JAR file?

Question

I have a program which consists of two simple Java Swing files.

How do I make an executable JAR file for my program?

Answer 1

Here it is in one line:

jar cvfe myjar.jar package.MainClass *.class

where MainClass is the class with your main method, and package is MainClass's package.

Note you have to compile your .java files to .class files before doing this.

c  create new archive
v  generate verbose output on standard output
f  specify archive file name
e  specify application entry point for stand-alone application bundled into an executable jar file

_{This answer inspired by Powerslave's comment on another answer.}