Catching an exception from another running Java application

Question

I've run into the issue where I have a program (not written by me, by someone else) I want to run 24/7, but sometimes it crashes. Normally, this wouldn't be an issue because I can simply create a process watcher that checks if it crashed, and then restarts it if necessary.

But, this particular program sometimes throws an exception and outputs it into the graphical interface that's integrated into it. In this instance, the program doesn't crash at all. The interface stays up, but the actual server functionality is unavailable.

Is there any way I can intercept this information from this process?

Answer 1

You want to use the Java Virtual Machine Tools Interface. I can't give you the code to catch your exception, but this is where to look. You'll have to do some detective work to find the class that throws the exception, or at least to find some indicator that it has been thrown.

Edit: You can also try calling the vendor to see if they know of a way. You can also look to see if it is writing the exception to a log file, which you could then watch.

Answer 2

This may or may not work, but if when the application displays it's error and the server stops working does the memory usage drop? If so you could probably just add some logic to your process monitor to call the windows command tasklist to see if the memory usage drops below some threshold. You'll have to check how much memory the program normally uses and how much it uses after the error though.

Since you said the server functionality stops working, another option could be to write a simple program that basically just pings the server how ever often you want to make sure it is still up. If not, kill the process and restart it.