多线程练习

写两个线程，一个线程打印1-52,另一个线程打印A-Z,打印顺序为12A34B…5152Z

//写两个线程，一个线程打印1-52,另一个线程打印A-Z,打印顺序为12A34B...5152Z

class Print
{
    private Integer num=1;
    private Integer flag=1;
    synchronized public void printNum()
    {
        while(num<27)
        {
            if(flag!=1)
            {
                try {
                    wait();  //等待打印字母
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            //打印数字
            if(num<27) //加判断是因为最后一次num=26,数字线程等待字母线程，当字母打印结束，
                // num=27,会唤醒数字线程，那么数字线程将会以num=27继续执行
            {
                System.out.print(num*2-1);
                System.out.print(num*2);
                flag=2;
                notify();//唤醒打印字母的线程
            }
        }
    }
    synchronized  public void printLetter()
    {
        while(num<27)
        {
            if(flag!=2)
            {
                try {
                    wait(); //此时应该打印数字。等待
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            //打印字母
            System.out.print((char)(num-1+'A'));
            num++;
            flag=1;
            notify();  //唤醒打印字母的线程
        }

    }
}

public class Print1A {
    public static void main(String[] args)
    {
        Print print=new Print();
        Thread numThread=new Thread(new Runnable() {
            @Override
            public void run() {
                print.printNum();
            }
        });
        Thread letterThread=new Thread(new Runnable() {
            @Override
            public void run() {
                print.printLetter();
            }
        });
        numThread.start();
        letterThread.start();
    }
}

12A34B56C78D910E1112F1314G1516H1718I1920J2122K2324L2526M2728N2930O3132P3334Q3536R3738S3940T4142U4344V4546W4748X4950Y5152Z

编写一个程序，启动三个线程，三个线程的名称分别是A,B,C；
// 每个线程将自己的名字在屏幕上打印5遍，打印顺序是
//ABCABCABCABCABC

//编写一个程序，启动三个线程，三个线程的名称分别是A,B,C；
// 每个线程将自己的名字在屏幕上打印5遍，打印顺序是
//ABCABCABCABCABC

class PrintABCI
{
    private Integer flag=1;
    private Integer count=1;  //打印次数

    public synchronized void printA()
    {
        while(flag!=1 )
        {
            try {
                wait();  //等待打印B或C
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.print('A');
        flag=2;
        notifyAll();
    }
    public synchronized void printB()
    {
        while(flag!=2 )
        {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.print('B');
        flag=3;
        notifyAll();
    }

    public synchronized void printC()
    {
        while(flag!=3)
        {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.print('C');
        count++;
        flag=1;
        notifyAll();
    }
}
public class PrintABC {
    public static void main(String[] args) {
        PrintABCI print=new PrintABCI();
        new Thread(new Runnable()
        {
            @Override
            public void run() {
                for(int i=0;i<5;i++)
                print.printA();
            }
        }).start();

        new Thread((new Runnable() {
            @Override
            public void run() {
                for(int i=0;i<5;i++)
                print.printB();
            }
        })).start();

        new Thread(new Runnable() {
            @Override
            public void run() {
                for(int i=0;i<5;i++)
                print.printC();
            }
        }).start();
    }

}