Debug everything under the sun

I think nothing should be too complicated. I belive if they explain something well, everything can be easily understood. But here, unfortunately, some explanations are missing. Do it yourself... I'm not saying it's impossible. But a good teacher would be a very great treasure: he/she would spare the next generation from having to rediscover everything... - If anybody ask me something, my attitude is that I like to explain everything well, in detail, in an understandable way, without skipping of steps. Sometimes I miss the same attitude from CodeGym. Here we are forced to suffer. But i think this is not the best way to learn: it's slow and inefficient. And that's why you're starting to feel like you're stupid. But you're not that.

Oliver, I know you made this post a while ago, and have since advanced a few levels. Still, I want to let you know that you matter regardless of any failings that you have at learning a particular skill. As for this specific problem, I've come to realize (very very slowly) that the problem is this -- just because you have set the TestedThread class's UncaughtExceptionHandler to be "handler" which was created above, this DOES NOT mean that any standard Thread classes we create will also have their UncaughtExceptionHandler set to "handler". The way that we solve this is by either setting our DefaultUncaughtExceptionHandler to "handler" thereby making all threads created use the same handler (the one that was created for us) OR we can go to each thread (threadA, threadB) and individually set their UncaughtExceptionHandler. Hope this helps! Dan

Although it's still hard for me to understand all the Oracle documentation, they provide the full picture. One day it will be an easy read I would hope. here is a quick summary of the above inhope it would help someone: you can change the way the un-handled exceptions get handled in Java. the default way in Java is printing out the familiar trace stack. to change the default behavior, create a class of your own that implements the Thread.UncaughtExceptionsHandler. once the class is created, override the uncaughtException method( this will let you handle any un-handled exceptions). now we need to decided weather to handle to un-handled exceptions for just a particular thread's exception, or for all threads( all threads' exceptions would mean all exceptions that are not handled): for just a particular thread: use the setUncaughtExceptionHandler( you own created class from above) ; for all un-handled exceptions: use setDefaultUncaughtExceptionHandler(you own created class from above); Hope that helps. please replay if there is something wrong with what I've said

thread is not an exception

fixed