巧妙方法1 利用数组的余数的特性

public class Myprint3 { private int i = 0;

public static void main(String[] args) {    Myprint3 myprint3 = new Myprint3();    new Thread(new Runnable() {        @Override        public void run() {            while (true) {               synchronized (myprint3){                   if(myprint3.i%3==0){                       System.out.println(Thread.currentThread().getName()+"A");                       myprint3.myPirnt();                   }               }            }        }    }).start();    new Thread(new Runnable() {        @Override        public void run() {            while (true) {                synchronized (myprint3){                    if(myprint3.i%3==1){                        System.out.println(Thread.currentThread().getName()+"B");                        myprint3.myPirnt();                    }                }            }        }    }).start();    new Thread(new Runnable() {        @Override        public void run() {            while (true) {                synchronized (myprint3){                    if(myprint3.i%3==2){                        System.out.println(Thread.currentThread().getName()+"C");                        myprint3.myPirnt();                    }                }            }        }    }).start();}public void myPirnt() {    i++;}复制代码

}

常规方法 使用三个信号量，开控制

public int i; public boolean a = true; public boolean b = false; public boolean c = false;

public static void main(String[] args) {    Myprint myprint = new Myprint();    new Thread(new Runnable() {        @Override        public void run() {            while (true) {                synchronized (myprint) {                    while (myprint.a) {                        myprint.getAdd();                        myprint.a=false;                        myprint.b=true;                        myprint.c=false;                    }                }            }        }    }).start();    new Thread(new Runnable() {        @Override        public void run() {            while (true) {                synchronized (myprint) {                    while (myprint.b) {                        myprint.getAdd();                        myprint.a=false;                        myprint.b=false;                        myprint.c=true;                    }                }            }        }    }).start();    new Thread(new Runnable() {        @Override        public void run() {            while (true) {                synchronized (myprint) {                    while (myprint.c) {                        myprint.getAdd();                        myprint.a=true;                        myprint.b=false;                        myprint.c=false;                    }                }            }        }    }).start();}public void getAdd() {    for (int j = 0; j < 5; j++) {        i++;        System.out.println(Thread.currentThread().getName()+i);    }}复制代码