记录一下使用两个线程交替打印1-100的操作:

/**
 * @description: 使用两个线程交替打印1-100
 * @author: Jay
 * @create: 2024-05-27 21:29
 **/
public class print_1_to_100 {
    static volatile int flag = 1; //此处需要加关键字volatile保证变量之间的可见性，否则程序将会阻塞在while循环中动不了（有点类似死锁）。
    public static void main(String[] args) {
        new Thread(new thread1()).start();
        new Thread(new thread2()).start();
    }
}

class thread1 implements Runnable{
    @Override
    public void run() {
        int i = 1;
        while (i<=99){
            if(print_1_to_100.flag == 1){
                System.out.println("线程1: " + i );
                i += 2;
                print_1_to_100.flag = 2;
            }
        }
    }
}
class thread2 implements Runnable{
    @Override
    public void run() {
        int i = 2;
        while (i<=100){
            if(print_1_to_100.flag == 2){
                System.out.println("线程2: " + i );
                i += 2;
                print_1_to_100.flag = 1;
            }
        }
    }
}

运行结果：