Weird output during JVM application execution in Eclipse - how to debug?

I've encountered weird Eclipse console output during my application execution. I'm almost 100% sur开发者_如何学Goe that it's my application's fault, but I couldn't find any information on how such output should be interpreted. After printing those characters, Eclipse freezes.

Screenshot here

My bet is problem with thread synchronisation, but how can I be sure what causes such behavior?

Try putting log printout messages before/after relevant code parts to trace where the problem lies. If it is related to threads, it may be difficult or impossible to reproduce in a debugger, since most concurrency bugs depend on subtle timing coincidences between the different threads.