测试 多线程 实现 callable 带返回值

 package threadTest;

 import java.util.ArrayList;
 import java.util.Date;
 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;

 /**
  *
  * 类  描  述： 测试 多线程 实现 callable 带返回值
  * 作        者： 赵         鹏
  */
 public class FutureTest {

     @SuppressWarnings("rawtypes")
     public static void main(String[] args) throws InterruptedException, ExecutionException {

         Date date1 = new Date();

         //线程池大小
         int taskSize = 5;

         //1创建一个线程池
         ExecutorService pool = Executors.newFixedThreadPool(taskSize);

         //2创建多个砝码绘制的List

         ArrayList<Future> list = new ArrayList<Future>();

         for (int i = 0; i < taskSize; i++) {

             Callable mCallable = new MCallable(i + "");
             //执行任务并获取任务对象
             @SuppressWarnings("unchecked")
             Future future = pool.submit(mCallable);

             //System.out.println("【>>>>>】" + future.get().toString());
             //将任务对象存入list中
             list.add(future);
         }

         //关闭线程组
         pool.shutdown();

         for (Future future : list) {

             // 从Future对象上获取任务的返回值，并输出到控制台
             System.out.println(">>>" + future.get().toString());
         }

         Date date2 = new Date();

         System.out.println("[程序执行完成的花费时间为]" + (date2.getTime()-date1.getTime()) + "毫秒");

     }

 }

 class MCallable implements Callable<Object> {

     private String taskNum;

     MCallable(String taskNum) {
         super();
         this.taskNum = taskNum;
     }

     @Override
     public Object call() throws Exception {
         System.out.println(">>> " + taskNum + " 任务开始运行");

         Date dateTemp1 = new Date();

         Thread.sleep(1000);

         Date dateTemp2 = new Date();

         long time = dateTemp2.getTime() - dateTemp1.getTime();

         System.out.println(">>>" +taskNum+ "任务【结束】运行");

         return "任务" +taskNum+ "执行完毕  ， 运行时间为【" + time +"】毫秒";
     }

 }