I cannot for the life of me attach the java source code to eclipse so I can see the inner workings of the language. Not even something as simple as the String Class.
Old question, be here's what I ended up using Java Source Attatcher plugin: http://marketplace.eclipse.org/content/java-source-attacher#.U85j4rF-N7s
It can provide source for different opensource projects. One weird thing thou, if you have libraries under libs folder, you cannot attach from there, but you need to attach source clicking on jar displayed under "Libraries from external".