java socket之传输实体类对象

2023-01-25 22:05:26

一、TCP编程

TCP协议是面向连接的、可靠地、有序的，以字节流的方式发送数据。java实现TCP通信依靠2个类：客户端的Socket类和服务器端的ServerSocket类。

基于TCP通信的Socket模型如下：

Socket通信的实现步骤如下：

1. 创建服务器端Socket：ServerSocket和客户端Socket：Socket；

2. 打开连接到Socket的InputStream/OutputStream;

3. 按照协议对Socket进行读写操作；

4. 关闭InputStream和OutputStream和Socket。

下面是一个例子：实现功能是，客户端向服务端发送一个User类实体对象，服务端每接收到一个请求便开启一个处理线程将用户信息打印出来，并向客户端发送“欢迎登录”。

1）工程结构

2）服务端和客户端信息交流类：User

为了能实现传输。客户端和服务端的User类的包结构要一样，该类必须要序列化

User类

package com.model;

import java.io.Serializable;

public class User implements Serializable {

    private int id;

    private String name;

    private String password;

    public User(int id, String name, String password) {

    super();

    this.id = id;

    this.name = name;

    this.password = password;

    }

    @Override

    public String toString() {

    return "User [id=" + id + ", name=" + name + ", password=" + password+ "]";

    }

}

3）服务端

simpleServer类，主要是用于接受请求并开起处理线程

package simpleSocketServer;

import java.io.IOException;

import java.net.InetAddress;

import java.net.ServerSocket;

import java.net.Socket;

public class simpleServer {

    public static void main(String[] args){

        try {

            ServerSocket serverSocket = new ServerSocket(9999);

            int count = 0;// 记录客户端的数量

            System.out.println("服务器启动，等待客户端的连接。。。");

            Socket socket = null;

            while(true){

                socket=serverSocket.accept();

                ++count;

                Thread serverHandleThread=new Thread(new ServerHandleThread(socket));

                serverHandleThread.setPriority(4);

                serverHandleThread.start();

                System.out.println("上线的客户端有" + count + "个！");

                InetAddress inetAddress = socket.getInetAddress();

                System.out.println("当前客户端的IP地址是："+inetAddress.getHostAddress());

            }

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

}

ServerHandleThread，服务器对socket进行处理的线程

package simpleSocketServer;

import java.io.IOException;

import java.io.InputStream;

import java.io.ObjectInputStream;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.net.Socket;

import com.model.User;

public class ServerHandleThread implements Runnable{

    Socket socket=null;

    public ServerHandleThread(Socket socket) {

        super();

        this.socket = socket;

    }

    @Override

    public void run() {

        // TODO Auto-generated method stub

        OutputStream os = null;

        PrintWriter pw = null;

        try {

            InputStream is = socket.getInputStream();

            ObjectInputStream ois=new ObjectInputStream(is);

            //readObject()方法必须保证服务端和客户端的User包名一致，要不然会出现找不到类的错误

            System.out.println("客户端发送的对象：" + (User) ois.readObject());

            socket.shutdownInput();// 禁用套接字的输入流

            os=socket.getOutputStream();

            pw=new PrintWriter(os);

            pw.println("欢迎登录！");

            pw.flush();

            socket.shutdownOutput();

        } catch (IOException | ClassNotFoundException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }finally{

            try{

                if(pw!=null){

                    pw.close();

                }

                if(os!=null){

                    os.close();

                }

                if(socket!=null){

                    socket.close();

                }

            }catch (IOException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

            }

        }

    }

}

4）客户端

package simpleSocketClient;

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;

import java.net.UnknownHostException;

import java.nio.file.attribute.UserPrincipalNotFoundException;

import javax.sound.midi.MidiDevice.Info;

import com.model.User;

/**

 * 基于TCP协议的Socket通信，实现用户登录-客户端

 */

public class Client {

    public static void main(String[] args) {

        // 1.创建客户端的Socket，指定服务器的IP和端口

        try {

            Socket socket = new Socket("127.0.0.1", 9999);

            // 2.获取该Socket的输出流，用来向服务器发送信息

            OutputStream os = socket.getOutputStream();

            ObjectOutputStream oos = new ObjectOutputStream(os);

            oos.writeObject(new User(1, "root", "123456"));

            socket.shutdownOutput();

            String infoString=null;

            // 3.获取输入流，取得服务器的信息

            InputStream is = socket.getInputStream();

            BufferedReader br=new BufferedReader(new InputStreamReader(is));

            String info=null;

            while((info=br.readLine())!=null){

                System.out.println("服务器端的信息：" + info);

            }

            socket.shutdownInput();

            oos.close();

            os.close();

            is.close();

            br.close();

            socket.close();

        } catch (UnknownHostException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

}

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