Java Executor never starts

Question

I'm currently having an issue where I'm setting up an ExecutorService, but the call to newFixedthreadPool never completes. I have a logger statement immediately after it that never executes.

Is there something about it that would be causing it to never complete? This has never happened before with the same code, so I'm very confused.

ExecutorService ex = Executors.newFixedThreadPool(this.numStreams); 
logger.trace("Thread pool set up.");                                
for (int i = 1; i <= this.numStreams; i++)                          
{                                                                   
    logger.trace("Starting a new thread for stream {}", i);         
    Future f = ex.submit(new TestThread(c, c.getStreamIterator(i), this.config));
    logger.trace("New thread has been started.");                   
}