线程state状态

//模拟网络延时：放大代码的发生性
public class TestSleep implements Runnable {
    //票数
    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) {

        TestThread4 ticket = new TestThread4();

        new Thread(ticket, "小明").start();
        new Thread(ticket, "老师").start();
        new Thread(ticket, "黄牛").start();
    }
}

//模拟倒计时，，，
public class TestSleep2 {

    public static void main(String[] args) {

        //打印当前系统时间
        Date startTime = 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(startTime));
                startTime = new Date(System.currentTimeMillis()); //更新当前时间
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    //模拟倒计时
    public static void tenDown() throws InterruptedException {
        int num = 10;

        while (true) {
            Thread.sleep(1000);
            System.out.println(num--);
            if (num <= 0) {
                break;
            }
        }
    }
}

//测试stop
//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不推荐使用的方法
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("run...Thread" + i++);
        }

    }

    //2.设置一个公开的方法停止线程，转换标志位
    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) {
                //调用stop方法切换标志位，让线程停止
                testStop.stop();
                System.out.println("线程该停止了");
            }
        }
    }
}

//观察测试线程状态
public class TestState {


    public static void main(String[] args) throws InterruptedException {
        Thread thread = new Thread(() -> {
            for (int i = 0; i < 5; i++) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            System.out.println("/////");
        });

        //观察状态
        Thread.State state = thread.getState();
        System.out.println(state);  //NEW

        //观察启动后
        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
            Thread.sleep(100);
            state = thread.getState();  //更新线程状态
            System.out.println(state); //输出状态
        }
    }
}

//测试join方法
//想象为插队
public class TestJoin implements Runnable {
    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("线程vip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 < 1000; i++) {
            if (i == 200) {
                thread.join(); //插队
            }
            System.out.println("main" + i );
        }
    }
}

//测试礼让线程
//礼让不一定成功，看CPU心情
public class TestYield {
    public static void main(String[] args) {
        MyYield myYield = new MyYield();

        new Thread(myYield, "a").start();
        new Thread(myYield, "b").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");
    }
}

//测试线程的优先级
public class TestPriority extends Thread {
    public static void main(String[] args) {

        //主线程默认优先级
        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);

        //先设置优先级，再启动
        t1.start();

        t2.setPriority(1);
        t2.start();

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

        t4.setPriority(Thread.MAX_PRIORITY);  //MAX_PRIORITY = 10
        t4.start();
    }

}

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

//测试守护线程
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表示是用户线程，正常的线程都是用户线程...

        thread.start(); //上帝守护线程启动

        new Thread(you).start(); //你 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 < 36500; i++) {
            System.out.println("你一生都开心的或者");
        }
        System.out.println("========goodbye! world! ==========");
    }
}

线程同步

//不安全的买票
//线程不安全，有负数
public class UnsafeBuyTicket {

    public static void main(String[] args) {
        BuyTicket station = new BuyTicket();

        new Thread(station, "苦逼的我").start();
        new Thread(station, "牛逼的你们").start();
        new Thread(station, "可恶的黄牛党").start();

    }
}

class BuyTicket implements Runnable {

    //票
    private int ticketNums = 10;
    boolean flag = true; //外部停止方式

    @Override
    public void run() {
        //买票

        while (flag) {
            try {
                buy();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }

    //synchronized 同步方法，锁的是this
    private synchronized void buy() throws InterruptedException {
        //判断是否有票
        if (ticketNums <= 0) {
            return;
        }

        //模拟延时
        Thread.sleep(100);

        //买票
        System.out.println(Thread.currentThread().getName() + "拿到" + ticketNums--);
    }
}

//不安全的取钱
//两个人去银行取钱，账户
public class UnsafeBank {
    public static void main(String[] args) {

        //账户
        Account account = new Account(100, "结婚基金");

        Drawing you = new Drawing(account, 50, "你");
        Drawing girlFriend = new Drawing(account, 100, "girlFriend");

        you.start();
        girlFriend.start();

    }
}

//账户
class Account {
    int money; //余额
    String name; //卡名

    public Account(int money, String name) {
        this.money = money;
        this.name = name;
    }
}

//银行：模拟取款
class Drawing extends Thread {
    Account account; //账户

    //取了多少钱
    int drawingMoney;

    //现在手上有多少钱
    int nowMoney;

    public Drawing(Account account, int drawingMoney, String name) {
        super(name);
        this.account = account;
        this.drawingMoney = drawingMoney;
    }

    //取钱
    //synchronized 默认锁的是this
    @Override
    public void run() {

        //锁的对象是变化的量，需要增删改的对象
        synchronized (account) {
            //判断有没有钱
            if (account.money - drawingMoney < 0) {
                System.out.println(Thread.currentThread().getName() + "钱不够，取不了");
                return;
            }

            //sleep放大问题的发生性
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            //卡内余额
            account.money = account.money - drawingMoney;
            //你手里的钱
            nowMoney = nowMoney + drawingMoney;

            System.out.println(account.name + "余额为:" + account.money);
            //Thread.currentThread().getName() = this.getName()
            System.out.println(this.getName() + "手里的钱" + nowMoney);
        }
    }
}

//线程不安全的集合
public class UnsafeList {

    public static void main(String[] args) {
        List<String> list = new ArrayList<String>();
        for (int i = 0; i < 10000; i++) {
            new Thread( ()-> {
                synchronized (list) {
                    list.add(Thread.currentThread().getName());
                }
            } ).start();
        }
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(list.size());
    }
}

//测试JUC安全类型的集合
public class TestJUC {
    public static void main(String[] args) {
        CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<String>();
        for (int i = 0; i < 10000; i++) {
            new Thread( ()->{
                list.add(Thread.currentThread().getName());
            } ).start();
        }

        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println(list.size());
    }
}

//死锁：多个线程互相抱有对方需要的资源，然后形成僵持
public class DeadLock {

    public static void main(String[] args) {
        Makeup g1 = new Makeup(0, "灰姑娘");
        Makeup g2 = new Makeup(1, "白雪公主");

        g1.start();
        g2.start();
    }

}

//口红
class Lipstick {
}

//镜子
class Mirror {

}

class Makeup extends Thread {

    //需要的资源只有一份，用static来保证只有一份
    static Lipstick lipstick = new Lipstick();
    static Mirror mirror = new Mirror();

    int choice; //选择
    String girlName; //使用化妆品的人

    public Makeup(int choice, String girlName) {
        this.choice = choice;
        this.girlName = girlName;
    }

    @Override
    public void run() {
        try {
            makeup();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    //化妆，互相持有对方的锁，就是需要拿到对方的资源
    private void makeup() throws InterruptedException {
        if (choice ==0) {
            synchronized (lipstick) {
                System.out.println(this.girlName + "获得口红的锁");
                Thread.sleep(1000);
                synchronized (mirror) {
                    System.out.println(this.girlName + "获得镜子的锁");
                }
            }
        } else {
            synchronized (mirror) {
                System.out.println(this.girlName + "获得镜子的锁");
                Thread.sleep(2000);
                synchronized (lipstick) {
                    System.out.println(this.girlName + "获得口红的锁");
                }
            }
        }
    }
}