Eclipse debugger always blocks on ThreadPoolExecutor without any obvious exception, why?

Unraveling daemon threads mysteries

Daemon threads in backends such as Tomcat, Hibernate, or Spring can throw runtime exceptions. The debugger routine halts in the tracks even if these exceptions aren't fatal to the threads.

Mitigating uncaught exceptions

To avoid unnecessary stops while debugging in Eclipse:

• Go to Preferences -> Java -> Debug
• Uncheck the group of friends nobody invited to the party: "Suspend execution on uncaught exceptions"

Alternatively, edit your Exception Breakpoints properties to exclude ThreadPoolExecutor.

Framework peculiarities

Playing nice with Tomcat

• Update your beast, Tomcat, to version 7.0.54 or higher to fix the critter messing up your debugging process.
• Give it a good old restart. Everybody needs a fresh start once in a while, right?

Harmonizing with Spring and Hibernate

• Tools like JRebel can be a real game-changer, handling hotswapping and easing your debugging life.
• Be aware that hotswapping in Spring Tool Suite (STS) might cause the debugger to halt.

Navigating ThreadPoolExecutor exceptions

Revising your approach

Know that frameworks could be using ThreadPoolExecutor under the hood, leading to unexpected breakpoints. Removing or filtering out breakpoints on the ThreadPoolExecutor can save you from involuntary debugger vacations.

Fine-tuning breakpoints

Setting breakpoints for specific runtime exceptions can streamline your debugging process.

Mastering the Eclipse debugger

Revealing hidden problems

With VisualVM you can monitor, troubleshoot and profile Eclipse, enhancing your debugging tools.

Confronting the invisible enemy

Uncaught exceptions thrown by a daemon thread might seem like a phantom menace. But with the right use of breakpoints in Eclipse, you reveal and confront them.

Pivoting your focus

Suspect higher-level code for uncaught exceptions. The ThreadPoolExecutor might just be an innocent bystander in this mystery.