在 Java 中关闭 ExecutorService 时显示友好消息？

Question

所以，我在 Java 中有一个关闭执行程序服务的代码，如下 -

public void shutdownExecutor() {
    executor.shutdown();
    try {
        executor.awaitTermination(requestInfo.getUploadThreadCount() * 30,
                TimeUnit.SECONDS);
    } catch (InterruptedException e) {
        logger.error(e);
    }
}

在上面的代码中，如您所见，客户端应用程序（控制台或 Web）变为空白，直到线程数 * 30 秒运行结束。如何在此处显示友好消息？

Answer 1

例如，我已将执行程序阻止 10 秒以进行测试。

ExecutorService executor = Executors.newFixedThreadPool(4);
executor.submit(() -> {
    try {
        Thread.sleep(10_000);
    } catch (Exception e) {
        e.printStackTrace();
    }
});
executor.shutdown();
System.out.println("The executor is shutting down, "+
                   "why not make yourself a cup of tea whilst you wait?");
try {
    executor.awaitTermination(5, TimeUnit.SECONDS);
} catch (InterruptedException e) {
    logger.error(e);
}

Answer 2

如果你的意思是你想在等待时显示一条周期性消息，你可以这样做（例如，每 1 秒显示一条消息，最多 30 秒）：

try {
  long endTime = System.nanoTime() + TimeUnit.SECONDS.toNanos(30);
  while (true) {
    long timeout = Math.min(
        TimeUnit.SECONDS.toNanos(1), endTime - System.nanoTime());
    if (timeout <= 0
        || executor.awaitTermination(timeout, TimeUnit.NANOSECONDS)) {
      break;
    }
    System.err.println("Still waiting for timeout");
  }
} catch (InterruptedException e) {
  logger.error(e);
  Thread.currentThread().interrupt();
}

在 Java 中关闭 ExecutorService 时显示友好消息？

Display friendly message when ExecutorService is shutting down in Java?

java

multithreading

threadpool

executorservice