java多线程-使用ReentrantLock实现线程的顺序执行

测试例子：

package serializer.pattern;

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

public class Main {

volatile private 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(){
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;
conditionA.signalAll();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
lock.unlock();
}
}
};

Thread threadB = new Thread(){
public void run(){
try {
lock.lock();
while(nextPrintWho != 2){
conditionA.await();
}

for(int i=0;i<3;i++){
System.out.println("ThreadB:"+(i+1));
}
nextPrintWho = 3;
conditionA.signalAll();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
lock.unlock();
}
}
};

Thread threadC = new Thread(){
public void run(){
try {
lock.lock();
while(nextPrintWho != 3){
conditionA.await();
}

for(int i=0;i<3;i++){
System.out.println("ThreadC:"+(i+1));
}
nextPrintWho = 1;
conditionA.signalAll();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
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();
}

}

}