Java 并发 : How can I tell which Future belongs to which Callable during processing?

Question

我有一个 Callable 集合和一个 ExecutorService。当我调用 All 时，我得到了一个 Future 对象的列表。在 Future 完成之前，我如何知道哪个 Future 对象映射到哪个 Callable？我可以事后说，因为

代码:

 ExecutorService es = .....;

 Collection<Callables> uniqueCallables = .....;  // each Callable is unique!

 List<Future> futures = es.invokeAll(uniqueCallables);

 // TODO--find unique Future A which is the future for Callable A!

Answer 1

基于 Java reference , invokeAll(uniqueCallables)保留 List<Future> 中的顺序作为 uniqueCallables.iterator() 产生的订单:

Returns: A list of Futures representing the tasks, in the same sequential order as produced by the iterator for the given task list, each of which has completed.