多线程第三种方式 Calls 实现

package Dao;import java.util.ArrayList;import java.util.Date;import java.util.List;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;public class callTest {public static void main(String[] args) {System.out.println("程序开始运行-----");Date date1 = new Date();int taskSize = 5;// 创建一个线程池ExecutorService pool = Executors.newFixedThreadPool(taskSize);List<Future> list = new ArrayList<Future>();for (int i = 0; i < taskSize; i++) {Callable c = new Calls(i + "  ");// 执行任务并获取Future对象Future f = pool.submit(c);list.add(f);}// 关闭线程池pool.shutdown();// 获取所有并发任务的运行结果for (Future f : list) {// 从Future对象上获取任务的返回值，并输出到控制台try {System.out.println(">>>" + f.get().toString());} catch (InterruptedException e) {e.printStackTrace();} catch (ExecutionException e) {e.printStackTrace();}}Date date2 = new Date();System.out.println("-----程序运行结束---运行时间="+ (date2.getTime() - date1.getTime()));}}
package Dao;import java.util.Date;import java.util.concurrent.Callable;public class Calls implements Callable<Object>{private String taskNum;   Calls(String taskNum) {this.taskNum = taskNum;}@Overridepublic Object call() throws Exception {System.out.println(">>>"+taskNum+"任务启动");Date dateTmp1=new Date();Thread.sleep(1000);Date dateTmp2=new Date();long time=dateTmp2.getTime()-dateTmp1.getTime();System.out.println(">>>"+taskNum+"任务终止");return taskNum+"任务返回结果，当前任务时间"+time+"毫秒";}}
//测试