Java多线程应用-condition的使用

来源：互联网发布：js 调用随机数编辑：程序博客网时间：2024/06/07 15:43

这是以前看过的张孝祥的多线程应用的视频，可以去网上搜这个视频，讲得很详细，值得一看。

下面是视频中讲到的一个condition的使用，用来控制多个线程阻塞和执行顺序，这个比await()、和notify()来控制线程的阻塞和执行好用的多，

它没有明确指定唤醒那条线程。

下面是一个实例：同起三条线程，分别执行private AAA a = new AAA(); 对象的三个方法，让三个方法按指定的顺序打印输入，先是ooo方法循环3次，接着nnn方法循环5次，接着mmm方法循环7次，这样依次执行循环10次

/** * @ClassName: ConditionTest * @author YangXuan * @date Aug 5, 2013 1:18:56 PM */public class ConditionTest {private AAA a = new AAA();// 多条线程操作的同一对象public static void main(String[] args) {ConditionTest c = new ConditionTest();c.aaa();}public void aaa() {new Thread(new Runnable() {public void run() {for (int i = 1; i <= 10; i++) {a.mmm(i);}}}, "I am Thread-3").start();new Thread(new Runnable() {public void run() {for (int i = 1; i <= 10; i++) {a.nnn(i);}}}, "I am Thread-2").start();new Thread(new Runnable() {public void run() {for (int i = 1; i <= 10; i++) {a.ooo(i);}}}, "I am Thread-1").start();}class AAA {private Lock lock = new ReentrantLock();private Condition condition1 = lock.newCondition();private Condition condition2 = lock.newCondition();private Condition condition3 = lock.newCondition();private int flag = 1;public void mmm(int count) {lock.lock();while (3 != flag) {try {condition3.await();} catch (InterruptedException e) {e.printStackTrace();}}System.out.println(Thread.currentThread().getName() + " --" + count+ "-- ");for (int i = 1; i <= 7; i++) {System.out.println(Thread.currentThread().getName()+ "  mmm loop of " + i);}System.out.println(); // 这里让线程3输出完后换一下行，好看一点condition1.signal();flag = 1;lock.unlock();}public void nnn(int count) {lock.lock();while (2 != flag) {try {condition2.await();} catch (InterruptedException e) {e.printStackTrace();}}System.out.println(Thread.currentThread().getName() + " --" + count+ "-- ");for (int i = 1; i <= 5; i++) {System.out.println(Thread.currentThread().getName()+ "  nnn loop of " + i);}flag = 3;condition3.signal();lock.unlock();}public void ooo(int count) {lock.lock();while (1 != flag) {try {condition1.await();} catch (InterruptedException e) {e.printStackTrace();}}System.out.println(Thread.currentThread().getName() + " --" + count+ "-- ");for (int i = 1; i <= 3; i++) {System.out.println(Thread.currentThread().getName()+ "  ooo loop of " + i);}flag = 2;condition2.signal();lock.unlock();}}}

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