Question

I am trying to execute a multithreaded program, using the Executors of Java. On execution the java thread terminates abnormally. I caught the exception , through try-catch, however, the exception has no message in it (null).

The failure is random, however I “suspect” that the failure is happening after I have made function calls in that thread. I tried to increase the thread stack size to 1024/2048 , but the result remains same.

Can someone please point out to the debugging approach to be adopted here. Since, I do not have the info about the exception I am not able to proceed with it.

I am working in Windows 64-bit environment, with java 1.6

Answer 1

While using the Executors class to create the thread pool use the method that accepts ThreadFactory; example ExecutorService newFixedThreadPool(int nThreads, ThreadFactory threadFactory).
In your implementation of the ThreadFactory, assign an UncaughtExceptionHandler; example below

public final Thread newThread(final Runnable r) {
    Thread newThread = threadFactory.newThread(r); // you can use default thread factory
    newThread.setName("threadName");
    newThread.setDaemon(Boolean.TRUE);
    newThread.setUncaughtExceptionHandler(new UncaughtExceptionHandler() {
        @Override
        public void uncaughtException(final Thread t, final Throwable e) {
            // log
        }
    });
    return newThread;
}