编辑代码

//文件名:ThreadB.java
class ThreadB implements Runnable { //定义类ThreadB实现Runnable接口
    int count = 1;
    int num;

    public ThreadB(int newNum) {
        num = newNum;
        System.out.println("创建线程" + num);
    }

    public void run() {
        while (true) {
            System.out.println("线程" + num + ":计数" + count);
            count++;
            if (count == 3)
                break;
        }
    }

    public static void main(String[] args) {
        Thread a1 = new Thread(new ThreadB(1)); //创建Thread的对象a1,传入参数new ThreadB(1)
        Thread a2 = new Thread(new ThreadB(2)); //创建Thread的对象a2,传入参数new ThreadB(2)
        Thread a3 = new Thread(new ThreadB(3)); //创建Thread的对象a3,传入参数new ThreadB(3)
        a1.start(); //调用a1的start()方法,启动线程a1
        a2.start(); //调用a2的start()方法,启动线程a2
        a3.start(); //调用a3的start()方法,启动线程a3
        System.out.println("主方法main()运行结束!");
    }
}