For starters: A JAR file (or Java ARchive) aggregates many files into one and is used by software developers to distribute Java classes and associated metadata through .jar files. Are you looking for a quick way to create executable JAR files? Small utility Java JarWizard makes .jar file creation process real easy.
It has neat wizard based interface to include required files. Just select and include files you want in the final .jar archive file and click next button. In the end, it creates executable .jar file that can be easily run by any user. Download Java JarWizard