DebugBreak equivalent in Java?

问题:

I'm looking for a way to break into the debugger from Java code, without setting a breakpoint in the IDE.

In Win32 there was DebugBreak(), in C# there's DebugBreak() Equivalent in C#, but I can't find anything in Java.

What I'm trying to do: say I have a wait with a 30s timeout, but in normal conditions that wait should always be <1s. I'd like to use ByteMan or something similar to wait with 1s timeout first, and break into the debugger if that wait timed out.

回答1:

Not a direct answer to your question but in most IDE's you can set conditional breakpoints.

This would require you to set a timestamp variable in your code before the timeout and test its value in your breakpoint, after the timeout. You would trigger your breakpoint conditional if the delta is greater than your threshold.

回答2:

The poster of this question has done exactly what I was looking for: Secure Debugging for Production JVMs

It reproduces the best feature of DebugBreak, that is you can attach the IDE to your program only after the "breakpoint" is hit.

回答3:

I created this class

import com.sun.jna.Library;

public interface Kernel32 extends Library {

    public void OutputDebugStringA(String Text);
    public void DebugBreak();    
}

then used it like this:

Kernel32 lib = (Kernel32) Native.loadLibrary("kernel32", Kernel32.class);
lib.OutputDebugStringA("just before DebugBreak\n");
lib.DebugBreak();

and that's it. It calls native function void WINAPI DebugBreak(void); inside Kernel32.dll

You also need the jar file jna-4.4.0.jar