java线程：几个实用的线程工具类

 

java线程：几个实用的线程工具类

分类： java_线程2012-07-04 16:29 89人阅读 评论(0) 收藏 举报

CyclicBarrier

import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @author amber2012
 *
 * CyclicBarrier:
 * 表示线程彼此等待，等所有的线程都集合后，才开始做任务
 *
 */
public class CyclicBarrierTest {

    public static void main(String[] args) {
        ExecutorService service = Executors.newCachedThreadPool();
        final  CyclicBarrier cb = new CyclicBarrier(3);
        for(int i=0;i<3;i++){
            Runnable runnable = new Runnable(){
                    public void run(){
                    try {
                        Thread.sleep((long)(Math.random()*10000));
                        System.out.println("线程" + Thread.currentThread().getName() +
                                "即将到达集合地点1，当前已有" + (cb.getNumberWaiting()+1) + "个已经到达，" + (cb.getNumberWaiting()==2?"都到齐了，继续走啊":"正在等候"));
                        cb.await();

                        Thread.sleep((long)(Math.random()*10000));
                        System.out.println("线程" + Thread.currentThread().getName() +
                                "即将到达集合地点2，当前已有" + (cb.getNumberWaiting()+1) + "个已经到达，" + (cb.getNumberWaiting()==2?"都到齐了，继续走啊":"正在等候"));
                        cb.await();
                        Thread.sleep((long)(Math.random()*10000));
                        System.out.println("线程" + Thread.currentThread().getName() +
                                "即将到达集合地点3，当前已有" + (cb.getNumberWaiting() + 1) + "个已经到达，" + (cb.getNumberWaiting()==2?"都到齐了，继续走啊":"正在等候"));
                        cb.await();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            };
            service.execute(runnable);
        }
        service.shutdown();
    }
}

CountDownLatch：

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @author amber2012
 *
 * CountDownLatch：
 * 好比倒计时计数器，调用CountDownLatch对象的CountDown方法就将计数器减1，当计数器到达0时，则所有等待线程
 * 或单个等待线程开始执行。
 */
public class CountdownLatchTest {

    public static void main(String[] args) {

        ExecutorService service = Executors.newCachedThreadPool();
        // 创建两个计数器，cdOrder的初始值为1，cdAnswer初始值为3
        final CountDownLatch cdOrder = new CountDownLatch(1);
        final CountDownLatch cdAnswer = new CountDownLatch(3);

        for(int i=0;i<3;i++){
            Runnable runnable = new Runnable(){
                    public void run(){
                    try {
                        System.out.println("线程" + Thread.currentThread().getName() + "正准备接受命令");
                        cdOrder.await(); // 所有的线程都在此等待，并希望被其他线程调用cdOrder.countDown()激活，在这里由主线程激活

                        System.out.println("线程" + Thread.currentThread().getName() + "已接受命令");
                        Thread.sleep((long)(Math.random()*10000));

                        System.out.println("线程" + Thread.currentThread().getName() + "回应命令处理结果");
                        cdAnswer.countDown();// cdAnswer计数器的初始值为3，，三个线程到达后调用cdAnswer.countDown()到计数为0，激活主线程
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            };
            service.execute(runnable);
        }

        try {
            Thread.sleep((long)(Math.random()*10000));

            System.out.println("线程" + Thread.currentThread().getName() + "即将发布命令");
            cdOrder.countDown();// 主线程将cdOrder计数器减1

            System.out.println("线程" + Thread.currentThread().getName() + "已发送命令，正在等待结果");
            cdAnswer.await();// 主线程正在等待，希望被其他线程激活

            System.out.println("线程" + Thread.currentThread().getName() + "已收到所有响应结果");
        } catch (Exception e) {
            e.printStackTrace();
        }
        service.shutdown();
    }
}

Exchanger：

import java.util.concurrent.Exchanger;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @author amber2012
 *
 * Exchanger:
 * 用于实现两个人之间的数据交换，每个人在完成一定的事务后想与对方交换数据，第一个先拿出数据的人将一直等待第二
 * 个人拿着数据到来时，才能彼此交换数据。
 */
public class ExchangerTest {

    public static void main(String[] args) {
        ExecutorService service = Executors.newCachedThreadPool();
        final Exchanger exchanger = new Exchanger();

        service.execute(new Runnable(){
            public void run() {
                try {
                    String data1 = "zxx";
                    System.out.println("线程" + Thread.currentThread().getName() + "正在把数据" + data1 +"换出去");
                    Thread.sleep(1000L);

                    String data2 = (String)exchanger.exchange(data1);
                    System.out.println("线程" + Thread.currentThread().getName() + "换回的数据为" + data2);
                }catch(Exception e){
                }
            }
        });

        service.execute(new Runnable(){
            public void run() {
                try {
                    String data1 = "lhm";
                    System.out.println("线程" + Thread.currentThread().getName() + "正在把数据" + data1 +"换出去");
                    Thread.sleep(2000L);

                    String data2 = (String)exchanger.exchange(data1);
                    System.out.println("线程" + Thread.currentThread().getName() + "换回的数据为" + data2);
                }catch(Exception e){
                }
            }
        });
    }
}