线程休眠方法sleep()

• 线程从运行状态到阻塞态
• 线程休眠：让当前的线程暂缓执行，等到了预计时间后再恢复执行
• 线程休眠会交出CPU，但是不会释放锁

class MyThread implements Runnable{
    public void run(){
        for(int i = 0;i < 10;i++){
            try {
                sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("当前线程："+Thread.currentThread().getName()+",i="+i);
        }
    }
}
public class ticket{
    public static void main(String[] args) {
        MyThread mt = new MyThread();
        new Thread(mt).start();
        new Thread(mt).start();
        new Thread(mt).start();

    }
}

线程让步方法yield()

• 线程从运行态到就绪
• 线程让步：暂停执行当前的线程对象，并执行其他线程
• yield()方法会让当前线程交出CPU，同样不会释放锁
• yield()方法无法控制具体交出CPU的时间
• 只能让拥有相同优先级的线程有获取CPU的机会

class MyThread implements Runnable{
    public void run(){
        for(int i = 0;i<10;i++){
            Thread.yield();
            System.out.println("当前线程："+Thread.currentThread().getName()+",i="+i);
        }
    }
}

public class ticket{
    public static void main(String[] args) {
        MyThread mt = new MyThread();
        new Thread(mt).start();
        new Thread(mt).start();
        new Thread(mt).start();
    }
}

join()方法–等待其他线程终止

• 运行到阻塞态
• 等待该线程终止：如果在主线程中调用该方法时就会让主线程休眠，让调用该方法的线程run方法先执行完毕之后再开始执行主线程

class MyThread implements Runnable{
    @Override
    public void run() {
        try {
            System.out.println("主线程睡眠前的时间");
            ticket.printTime();
            Thread.sleep(5000);
            System.out.println(Thread.currentThread().getName());
            System.out.println("睡眠结束的时间");
            ticket.printTime();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}
public class ticket{
    public static void main(String[] args) {
        MyThread mt = new MyThread();
        Thread thread = new Thread(mt,"子线程A");
        thread.start();
        System.out.println(Thread.currentThread().getName());
        try {
            thread.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("代码结束");
    }
    public static void printTime(){
        Date date = new Date();
        DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String time = format.format(date);
        System.out.println(time);
    }
}