Question

Sometimes, in Eclipse , i press a combination of keys which take me to the editor page that shows contents of my .class file (bytecode). I never seem to be able to remember what that key combination is.

Can someone please let me know?

Or in other words, how can one see own bytecode?

Answer 1

Eclipse’s default class file viewer shows the source (see VonC’s answer) if it has been associated with the binaries, otherwise it gives a javap-like view of the class (with an option to attach source). I’m guessing it’s the latter that you are looking for.

I’ve never found a way to cleanly force Eclipse to show that output rather than the linked source. What you probably want is an Eclipse plug-in that provides Javap like functionality (or an interface to javap). Look for plugins stating they “disassemble” (as opposed to “decompile,” like jad).

Barring a plug-in, you could probably configure an external tool to perform javap but it might not play nicely with other eclipse features.

Edit: Let me be clear about the above: If you hit F3, Eclipse does the following (generally, the actual procedure might be slightly different):

1. Resolves the target (if you are selecting a Java file, it will be the Java file itself; if you are selecting or your cursor is over a class name it will be the class declaration, similar for a method declaration, etc).
2. Searches the build path (same project first) for a Java file containing the target. If found, opens up an writable editor displaying that Java source file.

3. For class/method declarations, it continues searching references on your build path for a class file that contains the declaration. If it is found, then

   a) If the class file has had source attached to it, open up a read-only editor of the linked Java file.

   b) If the class file does not have source attached to it, then open up a read-only panel showing the disassembled (javap-like) bytecode of the compiled class file.

My guess would be that you’re thinking there’s a dedicated key sequence to 3.b), but I don’t think there is. But again, I would love to be proven wrong here.