Eclipse: How debug without source jar?

I am using Eclipse 3.4. I want to be able to put a breakpoint in a line of code that's in a jar开发者_运维问答 for which I dont have the source code and no source code is available. How can I do this?

Even without the source you can view the outlines for classes and from the outline view, set breakpoints on methods.

If you must see some representation of the source, these are both pretty good: http://jadclipse.sourceforge.net/wiki/index.php/Main_Page and http://java.decompiler.free.fr/

Try this: Bytecode Outline Plugin for Eclipse