问executorThreadPool检查任务何时完成或超时

EN

public static void main(String[] args) {
    ExecutorService executorService = Executors.newFixedThreadPool(10);

    Set<CompletableFuture<Integer>> calculations = new HashSet<>();

    CompletableFuture<Integer> sum = CompletableFuture.completedFuture(0);

    for (int i = 0; i < 100; i++) {
        // submit to thread pool
        CompletableFuture<Integer> calculation =
                CompletableFuture.supplyAsync(CompleteableFutureGather::longCalculation, executorService);
        calculations.add(calculation);
        sum = sum.thenCombine(calculation, Integer::sum); // set up future aggregation
    }
    int total = 0;
    try {
        total = sum.get(5, TimeUnit.SECONDS); // set timeout
    } catch (InterruptedException e) {
        Thread.currentThread().interrupt();
    } catch (ExecutionException e) {
        throw (RuntimeException) e.getCause();
    } catch (TimeoutException e) {
        // preemptively complete calculations with default value, those already completed will be unaffected
        calculations.forEach(integerCompletableFuture -> integerCompletableFuture.complete(0));
        total = sum.getNow(0); // everything is complete so partial aggregation will be returned immediately
    }
    System.out.println(total);
}

private static Integer longCalculation() {
    try {
        Thread.sleep(5000);
    } catch (InterruptedException e) {
        Thread.currentThread().interrupt();
    }
    return 1;
}