Condition实现多线程顺序打印

Condition实现多线程顺序打印：

　　

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;

public class Run {
    
    volatile public static int nextPrintWho = 1;
    private static ReentrantLock lock = new ReentrantLock();
    final private static Condition conditionA = lock.newCondition();
    final private static Condition conditionB = lock.newCondition();
    final private static Condition conditionC = lock.newCondition();
    
    public static void main(String[] args) {
        
        Thread threadA = new Thread() {
            @Override
            public void run() {
                try {
                    lock.lock();
                    while (nextPrintWho != 1) {
                        conditionA.await();
                    }
                    for (int i = 0; i < 3; i++) {
                        System.out.println("ThreadA " + (i+1));
                    }
                    nextPrintWho = 2;
                    conditionB.signalAll();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }finally {
                    lock.unlock();
                }
            };
        };
        Thread threadB = new Thread() {
            @Override
            public void run() {
                try {
                    lock.lock();
                    while (nextPrintWho != 2) {
                        conditionB.await();
                    }
                    for (int i = 0; i < 3; i++) {
                        System.out.println("ThreadB " + (i+1));
                    }
                    nextPrintWho = 3;
                    conditionC.signalAll();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }finally {
                    lock.unlock();
                }
            };
        };
        Thread threadC = new Thread() {
            @Override
            public void run() {
                try {
                    lock.lock();
                    while (nextPrintWho != 3) {
                        conditionC.await();
                    }
                    for (int i = 0; i < 3; i++) {
                        System.out.println("ThreadC " + (i+1));
                    }
                    nextPrintWho = 1;
                    conditionA.signalAll();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }finally {
                    lock.unlock();
                }
            };
        };
        Thread[] aArray = new Thread[5];
        Thread[] bArray = new Thread[5];
        Thread[] cArray = new Thread[5];
        for (int i = 0; i < 5; i++) {
            aArray[i] = new Thread(threadA);
            bArray[i] = new Thread(threadB);
            cArray[i] = new Thread(threadC);
            aArray[i].start();
            bArray[i].start();
            cArray[i].start();
        }
    }
}

运行结果如下：