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：