线程的5大基本状态

线程停止

*
1 建议线程正常停止  利用次数，不建议死循环
2 建议使用标志位    设置一个标志位
3 不要使用stop或者destroy等过时或者JDK不建议使用的方法
 */
public class TestStop implements Runnable {
    // 1设置一个标识位
    private boolean flag = true;
    @Override
    public void run() {
        int i = 0;
        while (flag){
            System.out.println("线程正在运行"+i++);
        }
    }
//    停止方法
    public void stop(){
        this.flag = false;
    }

    public static void main(String[] args) {
        TestStop testStop = new TestStop();
         new Thread(testStop).start();

        for (int i = 0; i < 1000; i++) {
            System.out.println("main"+i);
            if (i == 900){
                testStop.stop();
                System.out.println("线程停止了");
            }
        }
    }
}

线程休眠

public class TestSleep implements Runnable{
    private int ticketNums = 10;
    @Override
    public void run() {
        while (true){
            if (ticketNums<=0){
                break;
            }
            //模拟延时
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread().getName()+"-->拿到了第"+ticketNums-- +"票");
        }

    }

    public static void main(String[] args) {
        TestSleep testSleep = new TestSleep();
        new Thread(testSleep,"小明").start();
        new Thread(testSleep,"老师").start();
        new Thread(testSleep,"黄牛").start();

    }
}

获取系统当前时间

public class TestSleep2 {
    public static void main(String[] args) {
        Date starTime = new Date(System.currentTimeMillis());//获取系统当前时间
        while (true){
            try {
                Thread.sleep(1000);
                System.out.println(new SimpleDateFormat("HH:mm:ss").format(starTime));
                starTime =  new Date(System.currentTimeMillis());//更新时间
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

线程礼让

//礼让不一定成功
public class TestYield {
    public static void main(String[] args) {
        MyYield myYield = new MyYield();
        new Thread(myYield,"A线程").start();
        new Thread(myYield,"B线程").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()+"线程停止执行");
    }
}

线程强制执行 —join

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

    public static void main(String[] args) throws InterruptedException {
        TestJoin testJoin = new TestJoin();
        Thread thread = new Thread(testJoin);
        thread.start();
        //主线程
        for (int i = 0; i < 500; i++) {
            if (i == 10){
                thread.join();
            }
            System.out.println("主线程"+i);
        }
    }
}

线程状态观测

//观测线程的状态
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("/////");
        });
//观测状态
        Thread.State state = thread.getState();
        System.out.println(state);//NEW
//        观测启动后
        thread.start();
        state = thread.getState();
        System.out.println(state);//Run
        while (state != Thread.State.TERMINATED){//只要线程不终止就一直输出这个状态
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            state = thread.getState();//更新线程状态
            System.out.println(state);//输出状态
        }
    }

}

线程的优先级

//测试线程的优先级
public class TestPriority{
//    主线程的优先级
    public static void main(String[] args) {
        System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());
        MyPriority myPriority = new MyPriority();
        Thread t1 = new Thread(myPriority);
        Thread t2 = new Thread(myPriority);
        Thread t3 = new Thread(myPriority);
        Thread t4 = new Thread(myPriority);
        Thread t5 = new Thread(myPriority);
//        先设置优先级,在启动
        t1.start();
        t2.setPriority(1);
        t2.start();

        t3.setPriority(4);
        t3.start();

        t4.setPriority(Thread.MAX_PRIORITY);
        t4.start();
        
        t5.setPriority(3);
        t5.start();
    }
}
class MyPriority implements Runnable{
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());
    }
}

线程守护 daemon

// 测试守护线程
// 上帝守护你
public class TestDaemon {
    public static void main(String[] args) {
        God god = new God();
        You you = new You();
        Thread thread = new Thread(god);
        thread.setDaemon(true);//默认是false表示用户线程，正常的都是用户线程
        thread.start();//守护线程启动
        new Thread(new You()).start();//用户线程启动

    }

}
//上帝
class God implements Runnable{
    @Override
    public void run() {
        while (true){
            System.out.println("上帝保佑着你");
        }
    }
}
//你
class You implements Runnable{
    @Override
    public void run() {
        for (int i = 0; i < 365000; i++) {
            System.out.println("你开心的活着");
        }
        System.out.println("-=====good bye world！");
    }
}