Java多线程经典案例

1.三个售票窗口同时出售20张票

public class Demo1
{

    public static void main(String[] args)
    {
        TicketOffice ticketOffice = new TicketOffice(new Object(), 20);
        new Thread(ticketOffice, "窗口1").start();
        new Thread(ticketOffice, "窗口2").start();
        new Thread(ticketOffice, "窗口3").start();
    }
}

class TicketOffice implements Runnable
{
    private Object object;

    private int ticketNum;

    public TicketOffice(java.lang.Object object, int ticketNum)
    {
        this.object = object;
        this.ticketNum = ticketNum;
    }

    @Override
    public void run()
    {
        while (ticketNum > 0)
        {
            synchronized (object)
            {
                if (ticketNum <= 0)
                {
                    System.out.println(Thread.currentThread().getName() + "没有票了");
                }
                else
                {
                    System.out.println(Thread.currentThread().getName() + "卖出了一张票，剩余" + --ticketNum + "张票");
                    try
                    {
                        Thread.sleep(1000L);
                    }
                    catch (InterruptedException e)
                    {
                        e.printStackTrace();
                    }
                }
            }
        }
    }
}

2.创建两个线程，其中一个输出1-52，另外一个输出A-Z。输出格式要求：12A 34B 56C 78D ...

public class Demo2
{
    public static void main(String[] args)
    {
        Object object = new Object();
        new Thread(new Number(object)).start();
        new Thread(new Character(object)).start();
    }
}

class Number implements Runnable
{
    private Object object;

    public Number(Object object)
    {
        this.object = object;
    }

    @Override
    public void run()
    {
        synchronized (object)
        {
            for (int i = 1; i < 53; i++)
            {
                if (i > 1 && i % 2 == 1)
                {
                    System.out.print(" ");
                }
                System.out.print(i);
                if (i % 2 == 0)
                {
                    object.notifyAll();
                    try
                    {
                        object.wait();
                    }
                    catch (InterruptedException e)
                    {
                        e.printStackTrace();
                    }
                }
            }
        }
    }
}

class Character implements Runnable
{
    private Object object;

    public Character(Object object)
    {
        this.object = object;
    }

    @Override
    public void run()
    {
        synchronized (object)
        {
            for (char i = 'A'; i <= 'Z'; i++)
            {
                System.out.print(i);
                object.notifyAll();
                if (i < 'Z')
                {
                    try
                    {
                        object.wait();
                    }
                    catch (InterruptedException e)
                    {
                        e.printStackTrace();
                    }
                }
            }
        }
    }
}

3.

启动3个线程打印递增的数字, 线程1先打印1,2,3,4,5, 然后是线程2打印6,7,8,9,10, 然后是线程3打印11,12,13,14,15. 接着再由线程1打印16,17,18,19,20….以此类推, 直到打印到75. 程序的输出结果应该为:

线程1: 1 
线程1: 2 
线程1: 3 
线程1: 4 
线程1: 5

线程2: 6 
线程2: 7 
线程2: 8 
线程2: 9 
线程2: 10 
…

线程3: 71 
线程3: 72
线程3: 73 
线程3: 74 
线程3: 75

public class Demo3
{

    public static void main(String[] args)
    {
        Object object = new Object();
        new Thread(new PrintRunnable(object,1)).start();
        new Thread(new PrintRunnable(object,2)).start();
        new Thread(new PrintRunnable(object,3)).start();
    }

}

class PrintRunnable implements Runnable
{
    private static volatile int printNum = 0;

    private Object object;

    private int threadId;
    
    public PrintRunnable(Object object, int threadId)
    {
        super();
        this.object = object;
        this.threadId = threadId;
    }

    @Override
    public void run()
    {
        while (printNum < 75)
        {
            synchronized (object)
            {
                if (printNum / 5 % 3 + 1 == threadId)
                {
                    for (int i = 0; i < 5; i++)
                    {
                        System.out.println("线程" + threadId + ":" + (++printNum));
                    }
                    object.notifyAll();
                }
                else
                {
                    try
                    {
                        object.wait();
                    }
                    catch (InterruptedException e)
                    {
                        e.printStackTrace();
                    }
                }
            }
        }
    }
}