The first thing you need is a contract file. You can download and use this very basic sample file named contract. Or you can use any other file you like. Just be sure to name the file contract so it will work with the commands specified in this lesson.

Once you've got the contract file, place it into a JAR file. In your command window type the following:

jar cvf Contract.jar contract

This command creates a JAR file named Contract.jar and places the contract file inside it.