今天来练习一下synchronized

简单来利用synchronized实现一个字符串的交替打印

主要的实现设置一个全局的变量state，线程执行通过不断累加state，根据state对三取余的结果来判断该线程是否继续执行还是进入等待。并通过synchronized锁住一个共享变量lock来进行上锁。

最后创建三个线程并让其进入就绪态。

代码实现：

public class Test {private static final Object lock = new Object();private static volatile int state = 0;public static void main(String[] args) {Thread A = new Thread(new task("a", 0));Thread B = new Thread(new task("b", 1));Thread C = new Thread(new task("c", 2));A.start();B.start();C.start();}static class task implements Runnable {private String s;private int x;public task(String s, int x) {this.s = s;this.x = x;}@Overridepublic void run() {while(true) {synchronized (lock) {while (state % 3 != x) {try {lock.wait();} catch (InterruptedException e) {e.printStackTrace();}}System.out.println(s);state++;lock.notifyAll();}}}}
}

结果展示：结果会一直交替打印abc