To use the contents of the JInput.jar file for Eclipse users do the following.
1. Make an folder to put the JInput.jar in maybe call it "External Jars" here you can store any jars that you download and can easily find them in the same place for future use.
2. In Eclipse, locate the project folder and click the drop down arrow of the project in which you are going to be using this jars resources.
3. Right Click JRE System Library> Build Path> Configure Build Path
4. Click Add External Jars
5. Locate the folder you have your JInput.jar in and select the jar and click open.
6. Click OK on the Java Build Path window.
Now that you have your jar in your build path the next step is to import it at the top of any class file that will be using the methods from within the jar.
And thats it, hope it helped