Eclipse how to link a jar containing javadocs/source with its binary?

Question

I would like to have the javadoc comments contained in a jar file show in eclipse when I hover over a class.

For example, after downloading JODA-2.0, three jars are

Answer 1

The easiest way is :

1. Press control+(The word for which you want to see the Java doc)
2. A page will appear that has a button for attach source.Click This
3. Select External location.
4. Browse The location to Java folder than your jdk .Than select src .zip.
5. press OK.

The Problem is Solved.