package com.cn.test2; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.FutureTask; public class FutureTaskSample { static FutureTask<String> future = new FutureTask(new Callable<String>() { public String call() { try { Thread.sleep(3000) ; } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } return "testPageContent and provide that the operation is a time exhausted thing..."; } }); public static void main(String[] args) throws InterruptedException, ExecutionException { // Start a thread to let this thread to do the time exhausting thing new Thread(future).start(); // Main thread can do own required thing first doOwnThing(); // At the needed time, main thread can get the result System.out.println(future.get()); } public static String doOwnThing() { return "Do Own Thing"; } }
实例2
package com.cn.test2; import java.util.Random; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.FutureTask; public class FutureTaskDemo { public static void main(String[] args) { // 初始化一个Callable对象和FutureTask对象 Callable pAccount = new PrivateAccount(); FutureTask futureTask = new FutureTask(pAccount); // 使用futureTask创建一个线程 Thread pAccountThread = new Thread(futureTask); System.out.println("futureTask线程现在开始启动,启动时间为:" + System.nanoTime()); pAccountThread.start(); System.out.println("主线程开始执行其他任务"); // 从其他账户获取总金额 int totalMoney = new Random().nextInt(100000); System.out.println("现在你在其他账户中的总金额为" + totalMoney); System.out.println("等待私有账户总金额统计完毕..."); // 测试后台的计算线程是否完成,如果未完成则等待 while (!futureTask.isDone()) { try { Thread.sleep(500); System.out.println("私有账户计算未完成继续等待..."); } catch (InterruptedException e) { e.printStackTrace(); } } System.out.println("futureTask线程计算完毕,此时时间为" + System.nanoTime()); Integer privateAccountMoney = null; try { privateAccountMoney = (Integer) futureTask.get(); } catch (InterruptedException e) { e.printStackTrace(); } catch (ExecutionException e) { e.printStackTrace(); } System.out.println("您现在的总金额为:" + totalMoney + privateAccountMoney.intValue()); } } @SuppressWarnings("all") class PrivateAccount implements Callable { Integer totalMoney; @Override public Object call() throws Exception { Thread.sleep(5000); totalMoney = new Integer(new Random().nextInt(10000)); System.out.println("您当前有" + totalMoney + "在您的私有账户中"); return totalMoney; } }