Detect Stack Traces

Hello, I'm making a plugin that alerts developers (really just players with a permission) when a stack trace occurs in console. I'd like to be able to send live messages containing the exception (e.g. "NullPointerException"), the package, and the line number, so the instant a stack trace occurs it alerts staff. I know how to do the messaging and stuff, but how can I detect when an exception occurs? Any help is appreciated!

 

Well, would these errors be coming your plugin? It'd be a bit more complicated if you want to detect errors from other plugins.

 

Wizehh all errors from all plugins. You know, those ones that spam 20 lines in console.

 

Code:java

System.setOut();

I don't know how well that would work though. Since it completely hijacks printing to the console.

EDIT: This is for everything. Not just errors.

 

This is pretty much impossible. You can't know when something threw an exception and then read it and get the things you want to know. If you were able to do so, that would be amazing. But you can't.

 

chasechocolate lets bring in the big guns.

 

Interesting concept; I got a few potential ideas that I'll test tomorrow.

 

Stigosaurus TheBigSuperCraft Wizehh teej107 <: it's very much possible. Here's just a proof of concept that it can be done.

[mod edit: Removed third party build information]

For those who want to know how it's done: Catching outgoing log messages

 

It's possible; a few ideas that come to mind:
Hijack the SimpleCommandMap dispatch method and catching all errors there. (this will only work for command related errors)
Hijack System.err with System.setErr (but I don't think Bukkit prints out the stacktrace with printStackTrace; I think it prints it out to it's own logger)
You could possibly go bytecode level and basically rewrite plugins; but this will be very very tedious and probably not worth the effort.

A very very stupid theory:
Find a way to hack the Throwable class constructors. If you can screw with the constructors, you can pretty much manipulate errors to your will.

 

Cirno Could a console filter work?
Filter the console's output, detect if it is a stacktrace (Patterns?), then grab information based on the stracktrace

 

That's exactly what chasechocolate did

 

Cirno xTigerRebornx yeah you're on the right track. Bukkit.getLogger().addHandler(...)