多线程交替打印奇数偶数或者多线程交替打印ABC。本例中基于AtomicInteger 实现，也可以使用volatile关键字实现。

写一个demo实现多线程交替打印ABC，同理也可实现交替打印奇数偶数等；供小伙伴们参考

import java.util.concurrent.atomic.AtomicInteger;

public class ThreadDemo {
    volatile static int count = 0;
    static AtomicInteger atomicInteger = new AtomicInteger(0);

    public static void main(String[] s) {
        Thread t1 = new Thread(() -> {
            while (true) {
                if (atomicInteger.get() % 3 == 0) {
                    try {
                        Thread.sleep(1000L);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println("A" + (atomicInteger.getAndIncrement()));//获取当前值并自增1 是原子操作（此处可用volatile 修饰的int 类型字段代替）
                }
            }
        });

        Thread t2 = new Thread(() -> {
            while (true) {
                if (atomicInteger.get() % 3 == 1) {
                    try {
                        Thread.sleep(1000L);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println("BB" + (atomicInteger.getAndIncrement()));
                }
            }
        });

        Thread t3 = new Thread(() -> {
            while (true) {
                if (atomicInteger.get() % 3 == 2) {
                    try {
                        Thread.sleep(1000L);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println("CCC" + (atomicInteger.getAndIncrement()));
                }
            }
        });


        t1.start();
        t2.start();
        t3.start();
    }
}