线程----状态

线程----状态 线程状态

一旦进入死亡状态就不能再一次被启动

public class TestState {
    public static void main(String[] args) {
        Thread thread =  new Thread(()->{
            for (int i = 0; i < 5; i++) {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            System.out.println("-----------");
        });
        //观察状态
        Thread.State state = thread.getState();
        System.out.println(state);//

        //观察启动后
        thread.start();//线程启动
        state = thread.getState();
        System.out.println(state);

        while (state != Thread.State.TERMINATED){
            state = thread.getState();//更新线程状态
            System.out.println(state);//输出状态
        }

    }
}

…

线程方法

setPriority(int newPriority)  //更改线程优先级

线程休眠

static void sleep(long millis)

//sleep(时间)指定当前线程阻塞毫秒数

//sleep存在异常InterruptedException

//sleep时间达到后线程进行就绪状态

//sleep可以模拟网络延时（放大问题的发生性），倒计时

public class TenDown {
    public static void main(String[] args) {
        try {
            tenDown();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }
    public static void tenDown() throws InterruptedException {
        int num=10;
        while(true){
            Thread.sleep(1000);
            System.out.println(num--);
            if(num<=0){
                break;
            }
        }

    }
}

//打印系统时间

//打印系统时间
public class TenDown1 {
    public static void main(String[] args) {
        //打印当前时间
        Date startTime = new Date(System.currentTimeMillis());//获取当前系统时间
        while(true){
            try {
                Thread.sleep(1000);
                System.out.println(new SimpleDateFormat("HH:mm:ss").format(startTime));
                startTime = new Date(System.currentTimeMillis());//更新时间
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }
    }
    public static void tenDown() throws InterruptedException {
        int num=10;
        while(true){
            Thread.sleep(1000);
            System.out.println(num--);
            if(num<=0){
                break;
            }
        }

    }
}

//每个对象都有一个锁，sleep不会释放锁

等待该线程终止

void join()

public class TestJoin implements Runnable{
    @Override
    public void run() {
        for (int i = 0; i < 1000; i++) {
            System.out.println("线程mvp来了"+i);
        }
    }

    public static void main(String[] args) throws InterruptedException {
        //启动我们的线程
        TestJoin testJoin =new TestJoin();
        Thread thread  = new Thread(testJoin);
        thread.start();
        //主线程
        for (int i = 0; i < 500; i++) {
            if(i==200){
                thread.join();//插队
            }
            System.out.println("main"+i);
        }
        
    }
}

停止当前，执行其他

static void yield()

//礼让不一定成功
public class TestYield {
    public static void main(String[] args) {
        MyYield myYield= new MyYield();
        new Thread(myYield,"a卡卡西").start();
        new Thread(myYield,"b小李").start();
    }
}
class MyYield implements Runnable{

    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName()+"线程开始执行");
        Thread.yield();//礼让
        System.out.println(Thread.currentThread().getName()+"线程停止-———=");

    }
}

*使用标志位停止线程

//使用标志位停止线程
public class ThreadStop implements Runnable {
    //设置标志位
    private boolean flag=true;
    //重写run方法
    @Override
    public void run(){
        int i=0;
        while(flag){
        System.out.println("run --Thread ---"+i++);
        }
    }
    public void stop(){
        this.flag = false;
    }


    public static void main(String[] args) {
        ThreadStop threadstop = new ThreadStop();
        new Thread(threadstop).start();
        //
        for (int i = 0; i < 1000; i++) {
            System.out.println("main   "+i);
            if(i==900){
                //调用stop方法
                threadstop.stop();
                System.out.println("线程   停止");
            }
        }

    }
}

- 中断线程

  ```java
  void interrupt()
  ```

  - 查看线程状态

    ```java
    boolean isAlive()
    ```