java - 异步运行方法并能够查看其状态的最简单方法是什么？

Question

我想运行一个持久的操作并能够看到它的以下阶段:

1) 尚未运行

2)运行

3)完成了

4)完成时出现异常

我编写了下面的代码，看起来过于复杂。它使用三个类:Work , ThreadPoolExecutor , FutureTask<?> ，其中Work是手写的。

同时，工作部分重复 FutureTask<?>功能(异常存储，也在 Future 中完成，但在内部关闭)。

问题是:是否有任何几行方法可以从 Java、Groovy、GPars、Apache 等的预定义类中执行相同的操作？

代码:

public class AsyncRunAndTrackState {

   public static class Stub implements Runnable {
      @Override
      public void run() {
         try {
            Thread.sleep(1000);
         } catch (InterruptedException e) {
            e.printStackTrace();
         }
      }
   }

   public static class Work implements Runnable {

      private Exception exception;

      private boolean active;

      public synchronized Exception getException() {
         return exception;
      }

      public synchronized void setException(Exception exception) {
         this.exception = exception;
      }

      public synchronized boolean isActive() {
         return active;
      }

      public synchronized void setActive(boolean active) {
         this.active = active;
      }

      @Override
      public final void run() {

         setActive(true);
         setException(null);

         try {
            runImpl();
         }
         catch (Exception e) {
            setException(e);
         }
         finally {
            setActive(false);
         }

      }

      protected void runImpl() {
         System.out.println("Before");

         try {
            Thread.sleep(10000);
         } catch (InterruptedException e) {
            e.printStackTrace();
         }

         throw new RuntimeException("Some exception occurred");

         //System.out.println("After");
      }
   }

   static ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(1);

   static FutureTask<?> future;

   static Work work;

   public static void main(String[] args) {

      for(int i=0; i<10; ++i) {
         executor.submit(new Stub());
      }

      work = new Work();
      future = (FutureTask<?>) executor.submit(work);

      while(true) {

         System.out.println(String.format("future.done = %s, future.cancelled = %s", future.isDone(), future.isCancelled()));
         System.out.println(String.format("work.active = %s, work.exception = %s", work.isActive(), work.getException()));
         System.out.println();

         try {
            Thread.sleep(500);
         } catch (InterruptedException e) {
            e.printStackTrace();
         }

      }

   }
}

Answer 1

我通常使用数据流队列来通知异步 Activity 的状态更改。