Debugger in Java

[K Gupta]

Hi ,

I want to make a debugger with remote debugging option in Java.Can somebody give some pointers like which API to use and sample code.And I also need to know the theory behind debugging.

[Paul Sturrock]

Not an advanced question. Please choose an appropriate forum more carefully. Moving...

[Jesper de Jong]

The JVM has an interface called JVMTI (Java Virtual Machine Tool Interface) which is the interface you'll want to use if you're going to write a debugger for Java.

You could have a look at the source code for Eclipse or NetBeans, two open-source IDEs which both have very good debuggers built-in.

[Ulf Dittmer]

There's an excellent standalone debugger called JSwat which you can study. Is there a particular reason you're trying to build one yourself instead of using one of the existing ones? It'll be quite a project.

[K Gupta]

Thanks ...

@Ulf : Yes I know it will be quite a project but I want to make one as I have some specific requirements. Can you guide me toward some theory of debugger i.e how it works etc.

[Ulf Dittmer]

Can you tell us a bit about those special requirements? I am betting that it will be easier to start with something like JSwat and incorporating those than to roll your own from scratch. If those features could be of general interest, the lead developer of JSwat might even help you get them implemented, and incorporate them in the official version.

[Tim Holloway]

Since the Java VM has its own builtin debugger, every development system I know of uses that. Which is reasonable, because about the only other way you'll be able to see inside the system and set breakpoints, etc. is to create (and debug!) your own JVM.

There's no API I'm aware of - the developer tools simply send text debugging commands to the JVM debugger and present what they pull out of the debugger's text responses. Which should mean that telnet is the simplest remote debugger of them all.

BTW, the Unix "ddd" debugger also supports Java in addition to compiled languages. It's a plugin, I think, but I believe it came already enabled in the version of ddd that came with my Fedora Linux distro.

[Ilja Preuss]

Originally posted by Tim Holloway:
There's no API I'm aware of

So what would you call the JVMTI ???