java (08.02)

java基础

作者：孙慧敏

1. TCP练习

1.1 客户端向服务端发送一条数据

package com.java_high.Netprogram;
/*
 * TCP
 */
import java.io.OutputStream;
import java.net.Socket;
/*
 * 客户端
 * localhost
 * 127.0.0.1
 * IP地址
 * 
 * 字节流方式
 */
public class Demo01 {
    public static void main(String[] args) {
        try {
            //建立客户端Socket连接，指定服务器的位置为本机以及端口为9999
            Socket socket = new Socket("localhost",9999);
            //打开输入/输出流
            OutputStream os = socket.getOutputStream();
            //发送客户端信息，向输出流写入信息
            String str = "aabb";
            os.write(str.getBytes());
            socket.shutdownOutput();
            os.close();
            socket.close();
        } catch (Exception e1) {
            e1.printStackTrace();
        }
    }
}

package com.java_high.Netprogram;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
/*
 * 服务端
 */
public class Server01 {
    public static void main(String[] args) {
        try {
            //建立ServerSocket服务器  指定端口 开始监听
            ServerSocket serverSocket = new ServerSocket(9999);
            //使用accept获取Socket 
            Socket socket = serverSocket.accept();
            InputStream is = socket.getInputStream();
            byte by[] = new byte[1024];
            is.read(by);
            String str1 = new String(by);
            System.out.println(str1);
            is.close();
            socket.close();
            serverSocket.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

1.2 双向通信（序列化和反序列化）

package com.java_high.Netprogram;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.Socket;
/*
 * TCP
 * 序列化和反序列化
 */
public class Demo02 {
        public static void main(String[] args) {
            //初始化
            Socket socket = null;
            OutputStream out = null;
            InputStream in = null;
            try {
                socket = new Socket("127.0.0.1",7777);
                //打开输出流
                out = socket.getOutputStream();
                //创建用户对象并赋值
                User user = new User();
                user.setName("张三");
                user.setPwd("123abc");
                //序列化
                ObjectOutputStream oos = new ObjectOutputStream(out);
                oos.writeObject(user);
                //打开输入流
                in = socket.getInputStream();
                //接收服务器端响应，从输入流中读取信息
                BufferedReader bf = new BufferedReader(new InputStreamReader(in));
                String str = null;
                while((str=bf.readLine())!=null) {
                    System.out.println("我是客户端，服务器告诉我："+str);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }finally {
                try {
                    socket.close();
                    out.close();
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
}

package com.java_high.Netprogram;
/*
 * 服务端
 */
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class Server02 {
        public static void main(String[] args) {
            //初始化
            ServerSocket serverSocket = null;
            Socket socket = null;
            OutputStream out = null;
            InputStream in = null;
            try {
                //指定端口并监听
                serverSocket = new ServerSocket(7777);
                //使用accept()方法等待客户端发送信息
                socket = serverSocket.accept();
                //打开输入流
                in = socket.getInputStream();   
                //反序列化
                ObjectInputStream ois = new ObjectInputStream(in);
                User user = (User) ois.readObject();
                System.out.println("我是服务器，客户端用户名："+user.getName()+" 客户端密码："+user.getPwd());
                //打开输出流
                out = socket.getOutputStream();
                String str = "您登陆成功了";
                out.write(str.getBytes());  
            } catch (Exception e) {
                e.printStackTrace();
            }finally {
                try {
                    serverSocket.close();
                    socket.close();
                    in.close();
                    out.close();
                } catch (Exception e2) {
                    e2.printStackTrace();
                }
            }
        }
}

package com.java_high.Netprogram;
import java.io.Serializable;
public class User implements Serializable{
        private String name;
        private String pwd;
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public String getPwd() {
            return pwd;
        }
        public void setPwd(String pwd) {
            this.pwd = pwd;
        }
}

###2. UDP练习
```java
package com.java_high.Netprogram;
/*
 * UDP
 * 发送端先P后S
 */
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class Demo03 {
    public static void main(String[] args) {
        String msg = "您好，请问您在吗？";
        byte msginfo[] = new byte[1024];
        msginfo = msg.getBytes();
        try {
            InetAddress ia = InetAddress.getByName("localhost"); 
            //构建数据包
            //(发送消息(字节)，消息长度，InetAddress,端口号)
            DatagramPacket dp = new DatagramPacket(msginfo, msginfo.length, ia, 6666);
            DatagramSocket  ds = new DatagramSocket();
            //通过DatagramSocket下send方法  发送DatagramPacket数据包
            ds.send(dp);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
<div class="md-section-divider"></div>

package com.java_high.Netprogram;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
public class Server03 {
    public static void main(String[] args) {
        DatagramSocket ds = null;
        DatagramPacket dp = null;
        byte by[] = new byte[1024];
        try {
            ds = new DatagramSocket(6666);
            //(消息容器,消息容器长度)
            dp = new DatagramPacket(by, by.length);
            //获取数据包，赋给dp
            ds.receive(dp);
            //将数据包中的数据转换为字符串
            String msginfo = new String(by);
            System.out.println("我是服务器，客户端说："+msginfo);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}