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.
The option provided by"praveenak" can also be applied to any other jar files with source file provided. For example, for JavaFx, we right click jfxrt.jar, select "Properties" and enter jdk1.8.0_05/javafx-src.zip for "Path" under External location.