Java之【线程通信】--标志位练习2

布满荆棘的人生 2022-06-16 01:52 155阅读 0赞

**定义一个线程A，输出1 ～ 10之间的整数，定义一个线程B，逆序输出1 ～ 10之间的整数，要求线程A和线程B交替输出**

方法一：非标志位方法

package Homework;
    //1  定义一个线程A，输出1 ～ 10之间的整数，定义一个线程B，逆序输出1 ～ 10之间的整数，要求线程A和线程B交替输出
    public class Test1 {
        
        public static void main(String[] args){
            Object obj=new Object();
            A a=new A(obj);
            B b=new B(obj);
            a.start();
            b.start();
        }
    
    }
    
    class A extends Thread{
        
        Object obj;
    
        public A() {
            super();
        }
    
        public A(Object obj) {
            super();
            this.obj = obj;
        }
    
        //正序打印
        @Override
        public void run() {
            synchronized (obj) {
                for(int i=1;i<11;i++){
                    System.out.print(i+",");
                    obj.notify();
                    try {
                        obj.wait();
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
    
                }
            }
    
        }
    }
    class B extends Thread{
        
        Object obj;
        public B() {
            super();
        }
    
        public B(Object obj) {
            super();
            this.obj = obj;
        }
    
        //逆序打印
        @Override
        public void run() {
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            synchronized (obj) {
                for(int i=10;i>0;i--){
                    System.out.print(i+",");
                    obj.notify();
                    if(i>1){
                        try {
                            obj.wait();
                        } catch (InterruptedException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                }
            }
    
        }
    }

运行结果：  
![这里写图片描述][SouthEast]

**方法二：采用标志位**

package Homework;
    //1  定义一个线程A，输出1 ～ 10之间的整数，定义一个线程B，逆序输出1 ～ 10之间的整数，要求线程A和线程B交替输出
    public class Test2 {
        
        public static void main(String[] args){
            C c=new C();
            A1 a1=new A1(c);
            B1 b1=new B1(c);
            a1.start();
            b1.start();
        }
    }
    class A1 extends Thread{
        
        C c;
    
        public A1(C c) {
            super();
            this.c = c;
        }
    
        public A1() {
            super();
        }
        @Override
        public void run() {
    
            synchronized (c) {
                for(int i=1;i<11;i++){
                    if(c.flag==true){
                        try {
                            c.wait();
                        } catch (InterruptedException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                    c.print(i);
                    c.flag=true;
                    c.notify();
                }
            }
    
        }
    
    }
    class B1 extends Thread{
        
        C c;
    
        public B1(C c) {
            super();
            this.c = c;
        }
    
        public B1() {
            super();
        }
        @Override
        public void run() {
            synchronized (c) {
                for(int i=10;i>0;i--){
                    if(c.flag==false){
                        try {
                            c.wait();
                        } catch (InterruptedException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                    c.print(i);
                    c.flag=false;
                    c.notify();
                }
    
            }
    
        }
    }
    class C {
        
        boolean flag=false;//true A已经打印，B为打印 A等待
    
        public void print(int i){
            System.out.print(i+",");
        }
    }

运行结果  
![这里写图片描述][SouthEast 1]

[SouthEast]: /images/20220616/48a5a991b9274413821543352ebc3565.png
[SouthEast 1]: /images/20220616/e64ed2e3e58f48bb81c85408ea03c9dc.png