concurrency - How do I call some blocking method with a timeout in Java?

Question

Is there a standard nice way to call a blocking method with a timeout in Java? I want to be able to do:

// call something.blockingMethod();
// if it hasn't come back within 2 seconds, forget it

if that makes sense.

Thanks.

Answer 1

You could use an Executor:

ExecutorService executor = Executors.newCachedThreadPool();
Callable<Object> task = new Callable<Object>() {
   public Object call() {
      return something.blockingMethod();
   }
};
Future<Object> future = executor.submit(task);
try {
   Object result = future.get(5, TimeUnit.SECONDS); 
} catch (TimeoutException ex) {
   // handle the timeout
} catch (InterruptedException e) {
   // handle the interrupts
} catch (ExecutionException e) {
   // handle other exceptions
} finally {
   future.cancel(true); // may or may not desire this
}

If the future.get doesn't return in 5 seconds, it throws a TimeoutException. The timeout can be configured in seconds, minutes, milliseconds or any unit available as a constant in TimeUnit.

See the JavaDoc for more detail.