My IntelliJ IDEA stopped linking the Java source code after I upgraded my Mac to Java 6.
Well, that's because src.jar is no longer shipped with the standard Java distribution. Instead, you have to the get the developer version from Apple's developer connect website at http://connect.apple.com.
Here is the URL I used - it may not work for you unless you login.
Also, you can find where your Java is installed after you downloaded it from Developer Connection from these release notes. src.jar will be available at this location.
On my Mac, it is /Library/Java/JavaVirtualMachines/1.6.0_22-b04-307.jdk/Contents/Home/src.jar
Have a good one!
