Java ExecutorCompletionService How know which task is returned

Question

ExecutorService serv = Executors.newFixedThreadPool(5);
CompletionService<Integer> servive = new ExecutorCompletionService<>(serv);

for (int i = 0; i < 5; i++) {
  servive.submit(new MyTask(i));
}

for (int i = 0; i < 5; i++) {
  Future<Integer> f = null;
  try {
    f = servive.take();
  } catch (InterruptedException e) {
    e.printStackTrace();
  }
  //f.get()
}

I want to know which task or callable was completed in the first result( f.get() )
How do I do that, or what other functions?

Answer 1

好吧，它完全取决于JVM和任务，如何由JVM处理。