I have tried unchecking and checking that box inside windows-->preference-->compiler option-->Class file generation. Tried restarting the eclipse.But it didnt work. I am using "eclipse-jee-indigo-SR2-win32-x86_64". I have used src zip folder in jdk1.7.0_79.
I just want to write my own program, use map/list etc and debug through methods of these classes and see how it works internally.Please help
The message is complaining about your Java runtime not having debugging information. Attaching source does not fix this problem, it will only enable you to read the source. You didn't compile those classes using Eclipse, so the preference has no relevance. If you want to debug into rt.jar, you need to install and compile/run against a JDK, not a JRE, and even if you have a JDK installed, it sounds like that is not what is being used to run your Java Application. Check your Installed JREs preference page (hint: prefer only having JDKs there) and then your application's Launch Configuration to make sure it's using what you expect.