为什么 ExecutorService 不在流中工作?

Why ExecutorService is not working in a stream?

我正在通过流传递一组任务,这是一个简化的演示:

    ExecutorService executorService = Executors.newCachedThreadPool((r) -> {
        Thread thread = new Thread();
        thread.setDaemon(true); // even I removed this, it's still not working;
        return thread;
    });
    IntStream.range(0, TASK_COUNT).forEach(i -> {
        executorService.submit(() -> {
            out.println(i);
            return null;
        });
    });

所有任务提交后,我尝试等待所有任务完成使用:

    executorService.shutdown();
    executorService.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);

但是输出是none,什么也没有打印出来。

有什么问题吗?任何帮助将不胜感激。

一个奇怪的 find-out 是,当使用默认 DefaultThreadFactory 时,它正在工作。

ExecutorService executorService = Executors.newCachedThreadPool();

F.Y.I 守护线程是我已经检查过的原因。为了调试,我故意设置了它们。

您忘记将 Runnable 传递给 Thread 构造函数:

ExecutorService executorService = Executors.newCachedThreadPool(r -> {
    Thread thread = new Thread(r);
                               ^
    thread.setDaemon(false);
    return thread;
});