Java控制3个线程顺序执行2次

1、Demo

package com.fedomn.demo;

import java.util.concurrent.Semaphore;

public class semDemo{
public static void main(String[] args) {

final Semaphore semA = new Semaphore(1);
final Semaphore semB = new Semaphore(1);
final Semaphore semC = new Semaphore(1);

Thread T1 = new Thread(new Runnable() {
public void run() {
for(int i=0;i<2;i++){
try {
semA.acquire();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("A thread !");
semB.release();
}
}
});
Thread T2 = new Thread(new Runnable() {
public void run() {
for(int i=0;i<2;i++){
try {
semB.acquire();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("B thread !");
semC.release();
}
}
});
Thread T3 = new Thread(new Runnable() {
public void run() {
for(int i=0;i<2;i++){
try {
semC.acquire();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("C thread !");
semA.release();
}
}
});

try {
semB.acquire();
semC.acquire();
} catch (InterruptedException e) {
e.printStackTrace();
}
T1.start();
T2.start();
T3.start();
}
}

2、输出结果

A thread !
B thread !
C thread !
A thread !
B thread !
C thread !