Is it possible to set breakpoints at a specific bytecode instruction?

Question

I'm using jdb to remotely debug a Java application of which I don't have the source code. Furthermore, the application jars are obfuscated.

I can set method breakpoints but, is it possible to set breakpoints at a specific bytecode instruction within a method? The idea I have is to use some disassembler like javap to identify the interesting instructions.

Can jdb or other Java debugger do this?

Answer 1

You need line numbers to breakpoint on (something I assume has been removed). You can artificially add line numbers to the file using instrumentation and you will be able to breakpoint at every instruction if you wish.