Java 通过主线程实现子线程的超时控制

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package com.bill99.seashell.fsp.quartz.test;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
* 启动一个任务，然后等待任务的计算结果，如果等待时间超出预设定的超时时间，则中止任务。
*

*/
public class TaskTimeoutDemo {

public static void main(String[] args) {
System.out.println("Start ...");

ExecutorService exec = Executors.newCachedThreadPool();

// testTask(exec, 15); // 任务成功结束后等待计算结果，不需要等到15秒
testTask(exec, 1); // 只等待5秒，任务还没结束，所以将任务中止

exec.shutdown();
System.out.println("End!");
}

public static void testTask(ExecutorService exec, int timeout) {
  MyTask task = new MyTask();
  Future<Boolean> future = exec.submit(task);
  Boolean taskResult = null;
  String failReason = null;
  try {
   // 等待计算结果，最长等待timeout秒，timeout秒后中止任务
   taskResult = future.get(timeout, TimeUnit.SECONDS);
  } catch (InterruptedException e) {
   failReason = "主线程在等待计算结果时被中断！";
  } catch (ExecutionException e) {
   failReason = "主线程等待计算结果，但计算抛出异常！";
  } catch (TimeoutException e) {
   failReason = "主线程等待计算结果超时，因此中断任务线程！";
   exec.shutdownNow();
  }

System.out.println("\ntaskResult : " + taskResult);
System.out.println("failReason : " + failReason);
}
}

class MyTask implements Callable<Boolean> {

@Override
public Boolean call() throws Exception {
  // 总计耗时约10秒
  for (int i = 0; i < 100L; i++) {
   Thread.sleep(100); // 睡眠0.1秒
   System.out.print('-');
  }
  return Boolean.TRUE;
}
}