@Component("xxxBean")

public class Test{
  public static void main(String[] args){
    for(int i = 1;i<=5;i++){
      	Thread.sleep(1000);
        System.out.println(i)   
    } 
  }
}

public class Demo1_wait {
    public static void main(String[] args) throws InterruptedException {
	   // 步骤1 : 子线程开启,进入无限等待状态, 没有被唤醒,无法继续运行.
        new Thread(() -> {
            try {

                System.out.println("begin wait ....");
                synchronized ("") {
                    "".wait();
                }
                System.out.println("over");
            } catch (Exception e) {
            }
        }).start();
    }

public class Demo2_notify {
    public static void main(String[] args) throws InterruptedException {
	   // 步骤1 : 子线程开启,进入无限等待状态, 没有被唤醒,无法继续运行.
        new Thread(() -> {
            try {

                System.out.println("begin wait ....");
                synchronized ("") {
                    "".wait();
                }
                System.out.println("over");
            } catch (Exception e) {
            }
        }).start();

        //步骤2:  加入如下代码后, 3秒后,会执行notify方法, 唤醒wait中线程.
        Thread.sleep(3000);
        new Thread(() -> {
            try {
                synchronized ("") {
                    System.out.println("唤醒");
                    "".notify();
                }
            } catch (Exception e) {
            }
        }).start();
    }
}

定义一个集合，包子铺线程完成生产包子，包子添加到集合中；吃货线程完成购买包子，包子从集合中移除。
1. 当包子没有时（包子状态为false），吃货线程等待.
2. 包子铺线程生产包子（即包子状态为true），并通知吃货线程（解除吃货的等待状态）

public class BaoZiPu extends Thread{
    private List<String> list ;
    public BaoZiPu(String name,ArrayList<String> list){
        super(name);
        this.list = list;
    }
    @Override
    public void run() {
        	int i = 0; 
            while(true){
                    //list作为锁对象
                    synchronized (list){
                        if(list.size()>0){
                            //存元素的线程进入到等待状态
                            try {
                                list.wait();
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        }

                        //如果线程没进入到等待状态 说明集合中没有元素
                        //向集合中添加元素
                        list.add("包子"+i++);
                        System.out.println(list);
                        //集合中已经有元素了 唤醒获取元素的线程
                        list.notify();
                    }
                }
            }
    }
}

public class ChiHuo extends Thread {

    private List<String> list ;
    public ChiHuo(String name,ArrayList<String> list){
        super(name);
        this.list = list;
    }

    @Override
    public void run() {
 			//为了能看到效果 写个死循环
                while(true){
                    //由于使用的同一个集合 list作为锁对象
                    synchronized (list){
                        //如果集合中没有元素 获取元素的线程进入到等待状态
                        if(list.size()==0){
                            try {
                                list.wait();
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        }
                        //如果集合中有元素 则获取元素的线程获取元素(删除)
                        list.remove(0);
                        //打印集合 集合中没有元素了
                        System.out.println(list);
                        //集合中已经没有元素 则唤醒添加元素的线程 向集合中添加元素
                        list.notify();
                    }
                }
            }
    }
}

public class Demo {
    public static void main(String[] args) {
        //等待唤醒案例
        List<String> list = new ArrayList<>();
        // 创建线程对象        
         BaoZiPu bzp = new BaoZiPu("包子铺",list);
        ChiHuo ch = new ChiHuo("吃货",list);
        // 开启线程
        bzp.start();
        ch.start();
    }
}

public class VolatileThread extends Thread {

    // 定义成员变量
    private boolean flag = false ;
    public boolean isFlag() { return flag;}

    @Override
    public void run() {

        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        // 将flag的值更改为true
        this.flag = true ;
        System.out.println("flag=" + flag);

    }
}

public class VolatileThreadDemo {// 测试类
    
    public static void main(String[] args) {

        // 创建VolatileThread线程对象
        VolatileThread volatileThread = new VolatileThread() ;
        volatileThread.start();

        // main方法
        while(true) {
            if(volatileThread.isFlag()) {
                System.out.println("执行了======");
            }
        }
    }
}

// main方法
while(true) {
    synchronized (volatileThread) {
        if(volatileThread.isFlag()) {
            System.out.println("执行了======");
        }
    }
}

private volatile boolean flag ;

public class VolatileAtomicThread implements Runnable {

    // 定义一个int类型的遍历
    private int count = 0 ;

    @Override
    public void run() {
        // 对该变量进行++操作，100次
        for(int x = 0 ; x < 100 ; x++) {
            count++ ;					
            System.out.println("count =========>>>> " + count);
        }
    }

}

public class VolatileAtomicThreadDemo {

    public static void main(String[] args) {

        // 创建VolatileAtomicThread对象
        VolatileAtomicThread volatileAtomicThread = new VolatileAtomicThread() ;

        // 开启100个线程对count进行++操作
        for(int x = 0 ; x < 100 ; x++) {
            new Thread(volatileAtomicThread).start();
        }
        
    }

}

// 定义一个int类型的变量
private volatile int count = 0 ;

public class VolatileAtomicThread implements Runnable {

    // 定义一个int类型的变量
    private volatile int count = 0 ;
    private static final Object obj = new Object();

    @Override
    public void run() {

        // 对该变量进行++操作，100次
        for(int x = 0 ; x < 100 ; x++) {
            synchronized (obj) {
                count++ ;
                System.out.println("count =========>>>> " + count);
            }
        }

    }

}

public AtomicInteger()：	   				初始化一个默认值为0的原子型Integer
public AtomicInteger(int initialValue)： 初始化一个指定值的原子型Integer

int get():   			 				 获取值
int getAndIncrement():      			 以原子方式将当前值加1，注意，这里返回的是自增前的值。
int incrementAndGet():     				 以原子方式将当前值加1，注意，这里返回的是自增后的值。
int addAndGet(int data):				 以原子方式将输入的数值与实例中的值（AtomicInteger里的value）相加，并返回结果。
int getAndSet(int value):   			 以原子方式设置为newValue的值，并返回旧值。

public class VolatileAtomicThread implements Runnable {

    // 定义一个int类型的变量
    private AtomicInteger atomicInteger = new AtomicInteger() ;

    @Override
    public void run() {

        // 对该变量进行++操作，100次
        for(int x = 0 ; x < 100 ; x++) {
            int i = atomicInteger.getAndIncrement();
            System.out.println("count =========>>>> " + i);
        }

    }

}

public class Const {
	public static HashMap<String,String> map = new HashMap<>();
}

public void run() {
		for (int i = 0; i < 500000; i++) {
			Const.map.put(this.getName() + (i + 1), this.getName() + i + 1);
		}
    	System.out.println(this.getName() + " 结束！");
	}

public class Demo {
	public static void main(String[] args) throws InterruptedException {
		Thread1A a1 = new Thread1A();
		Thread1A a2 = new Thread1A();
		a1.setName("线程1-");
		a2.setName("线程2-");

		a1.start();
		a2.start();
		//休息10秒，确保两个线程执行完毕
		Thread.sleep(1000 * 5);
		//打印集合大小
		System.out.println("Map大小：" + Const.map.size());
	}
}

public synchronized V put(K key, V value) 
public synchronized V get(Object key)

public CountDownLatch(int count)// 初始化一个指定计数器的CountDownLatch对象

public void await() throws InterruptedException// 让当前线程等待
public void countDown()	// 计数器进行减1

public class ThreadB extends Thread {
    private CountDownLatch down ;
    public ThreadB(CountDownLatch down) {
        this.down = down;
    }
    @Override
    public void run() {
        System.out.println("B");
        down.countDown();
    }
}

public class Demo {
    public static void main(String[] args) {
        CountDownLatch down = new CountDownLatch(1);//创建1个计数器
        new ThreadA(down).start();
        new ThreadB(down).start();
    }
}

public CyclicBarrier(int parties, Runnable barrierAction)// 用于在线程到达屏障时，优先执行barrierAction，方便处理更复杂的业务场景

public int await()// 每个线程调用await方法告诉CyclicBarrier我已经到达了屏障，然后当前线程被阻塞

public class MeetingThread extends Thread {
    @Override
    public void run() {
        System.out.println("好了，人都到了，开始开会......");
    }
}

public class Demo {
	public static void main(String[] args) {
		CyclicBarrier cbRef = new CyclicBarrier(5, new MeetingThread());//等待5个线程执行完毕，再执行MeetingThread
		PersonThread p1 = new PersonThread(cbRef);
		PersonThread p2 = new PersonThread(cbRef);
		PersonThread p3 = new PersonThread(cbRef);
		PersonThread p4 = new PersonThread(cbRef);
		PersonThread p5 = new PersonThread(cbRef);
		p1.start();
		p2.start();
		p3.start();
		p4.start();
		p5.start();
	}
}

public Semaphore(int permits)						permits 表示许可线程的数量
public Semaphore(int permits, boolean fair)			fair 表示公平性，如果这个设为 true 的话，下次执行的线程会是等待最久的线程

public void acquire() throws InterruptedException	表示获取许可
public void release()								release() 表示释放许可

public class Service {
    private Semaphore semaphore = new Semaphore(1);//1表示许可的意思，表示最多允许1个线程执行acquire()和release()之间的内容
    public void testMethod() {
        try {
            semaphore.acquire();
            System.out.println(Thread.currentThread().getName()
                    + " 进入 时间=" + System.currentTimeMillis());
            Thread.sleep(1000);
            System.out.println(Thread.currentThread().getName()
                    + "   结束 时间=" + System.currentTimeMillis());
            semaphore.release();
			//acquire()和release()方法之间的代码为"同步代码"
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

public class ThreadA extends Thread {
	private Service service;
	public ThreadA(Service service) {
		super();
		this.service = service;
	}
	@Override
	public void run() {
		service.testMethod();
	}
}

public class Demo {
	public static void main(String[] args) {
		Service service = new Service();
        //启动5个线程
		for (int i = 1; i <= 5; i++) {
			ThreadA a = new ThreadA(service);
			a.setName("线程 " + i);
			a.start();//5个线程会同时执行Service的testMethod方法，而某个时间段只能有1个线程执行
		}
	}
}

public Exchanger()

public V exchange(V x)

public class ThreadA extends Thread {
	private Exchanger<String> exchanger;
	public ThreadA(Exchanger<String> exchanger) {
		super();
		this.exchanger = exchanger;
	}
	@Override
	public void run() {
		try {
			System.out.println("线程A欲传递值'礼物A'给线程B，并等待线程B的值...");
			System.out.println("在线程A中得到线程B的值=" + exchanger.exchange("礼物A"));

		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

}

public class Demo {
	public static void main(String[] args) {
		Exchanger<String> exchanger = new Exchanger<String>();
		ThreadA a = new ThreadA(exchanger);
		a.start();
	}
}

public class ThreadA extends Thread {
	private Exchanger<String> exchanger;
	public ThreadA(Exchanger<String> exchanger) {
		super();
		this.exchanger = exchanger;
	}
	@Override
	public void run() {
		try {
			System.out.println("线程A欲传递值'礼物A'给线程B，并等待线程B的值...");
			System.out.println("在线程A中得到线程B的值=" + exchanger.exchange("礼物A"));
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

public class ThreadB extends Thread {
	private Exchanger<String> exchanger;
	public ThreadB(Exchanger<String> exchanger) {
		super();
		this.exchanger = exchanger;
	}
	@Override
	public void run() {
		try {
			System.out.println("线程B欲传递值'礼物B'给线程A，并等待线程A的值...");
			System.out.println("在线程B中得到线程A的值=" + exchanger.exchange("礼物B"));

		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

public class Demo {
	public static void main(String[] args) throws InterruptedException {
		Exchanger<String> exchanger = new Exchanger<String>();
		ThreadA a = new ThreadA(exchanger);
		ThreadB b = new ThreadB(exchanger);
		a.start();
		b.start();
	}
}

public class ThreadA extends Thread {
	private Exchanger<String> exchanger;
	public ThreadA(Exchanger<String> exchanger) {
		super();
		this.exchanger = exchanger;
	}
	@Override
	public void run() {
		try {
			System.out.println("线程A欲传递值'礼物A'给线程B，并等待线程B的值，只等5秒...");
			System.out.println("在线程A中得到线程B的值 =" + exchanger.exchange("礼物A",5, TimeUnit.SECONDS));
			System.out.println("线程A结束！");
		} catch (InterruptedException e) {
			e.printStackTrace();
		} catch (TimeoutException e) {
			System.out.println("5秒钟没等到线程B的值，线程A结束！");
		}
	}
}

public class Run {
	public static void main(String[] args) {
		Exchanger<String> exchanger = new Exchanger<String>();
		ThreadA a = new ThreadA(exchanger);
		a.start();
	}
}

public class MyRunnable implements Runnable {
    @Override
    public void run() {
        System.out.println("我要一个教练");
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("教练来了： " + Thread.currentThread().getName());
        System.out.println("教我游泳,交完后，教练回到了游泳池");
    }
}

public class ThreadPoolDemo {
    public static void main(String[] args) {
        // 创建线程池对象
        ExecutorService service = Executors.newFixedThreadPool(2);//包含2个线程对象
        // 创建Runnable实例对象
        MyRunnable r = new MyRunnable();

        //自己创建线程对象的方式
        // Thread t = new Thread(r);
        // t.start(); ---> 调用MyRunnable中的run()

        // 从线程池中获取线程对象,然后调用MyRunnable中的run()
        service.submit(r);
        // 再获取个线程对象，调用MyRunnable中的run()
        service.submit(r);
        service.submit(r);
        // 注意：submit方法调用结束后，程序并不终止，是因为线程池控制了线程的关闭。
        // 将使用完的线程又归还到了线程池中
        // 关闭线程池
        //service.shutdown();
    }
}

public class ThreadPoolDemo2 {
    public static void main(String[] args) throws Exception {
        // 创建线程池对象
      ExecutorService service = Executors.newFixedThreadPool(2);//包含2个线程对象

        // 创建Runnable实例对象
        Callable<Double> c = new Callable<Double>() {
            @Override
            public Double call() throws Exception {
                return Math.random();
            }
        };

        // 从线程池中获取线程对象,然后调用Callable中的call()
        Future<Double> f1 = service.submit(c);
        // Futur 调用get() 获取运算结果
        System.out.println(f1.get());

        Future<Double> f2 = service.submit(c);
        System.out.println(f2.get());

        Future<Double> f3 = service.submit(c);
        System.out.println(f3.get());
    }
}

public class Demo04 {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        ExecutorService pool = Executors.newFixedThreadPool(3);

        SumCallable sc = new SumCallable(100);
        Future<Integer> fu = pool.submit(sc);
        Integer integer = fu.get();
        System.out.println("结果: " + integer);
        
        SumCallable sc2 = new SumCallable(200);
        Future<Integer> fu2 = pool.submit(sc2);
        Integer integer2 = fu2.get();
        System.out.println("结果: " + integer2);

        pool.shutdown();
    }
}

public class SumCallable implements Callable<Integer> {
    private int n;

    public SumCallable(int n) {
        this.n = n;
    }

    @Override
    public Integer call() throws Exception {
        // 求1-n的和?
        int sum = 0;
        for (int i = 1; i <= n; i++) {
            sum += i;
        }
        return sum;
    }
}

public class Demo05 {
    public static void main(String[] args) {
        MyRunnable mr = new MyRunnable();

        new Thread(mr).start();
        new Thread(mr).start();
    }
}

class MyRunnable implements Runnable {
    Object objA = new Object();
    Object objB = new Object();

    /*
    嵌套1 objA
    嵌套1 objB
    嵌套2 objB
    嵌套1 objA
     */
    @Override
    public void run() {
        synchronized (objA) {
            System.out.println("嵌套1 objA");
            synchronized (objB) {// t2, objA, 拿不到B锁,等待
                System.out.println("嵌套1 objB");
            }
        }

        synchronized (objB) {
            System.out.println("嵌套2 objB");
            synchronized (objA) {// t1 , objB, 拿不到A锁,等待
                System.out.println("嵌套2 objA");
            }
        }
    }
}