Java 基于BIO实现 Client与Server通信

基于BIO实现 Client与Server通信

1、简述BIO模型中服务端与客户端的响应过程

根据上图可清晰看出，Client与Server的响应流程如下：

1、Server 服务器端 serverSocket先要和端口进行绑定

ServerSocket serverSocket = new ServerSocket(6767);  

2、绑定完成后，通过accept方法，阻塞式等待客户端的连接，这个方法是阻塞式调用，直到有客户端连接才往下执行；

 Socket accept = serverSocket.accept();

3、客户端创建Socket对象，绑定服务器的ip地址与端口号，与服务器进行连接

 //建立socket连接  host=127.0.0.1   port=6767
socket = new Socket(host, port);

4、服务器接收到客户端的连接请求，accept方法获取到客户端的socket信息，连接成功
服务器与客户端创建各自的io流，实现全双工通信

2、案例实现

客户端：

package com.xiaojie.net;

import java.io.*;
import java.net.Socket;

/**
 * @author Mrli
 * @date 2020/9/25 19:36
 */
public class Client {
    public static void main(String[] args) {
        final String host = "127.0.0.1";
        final int port = 6767;
        final String QUIT = "quit";

        Socket socket = null;
        BufferedReader reader = null;
        BufferedWriter writer = null;

        try {
            //建立socket连接
            socket = new Socket(host, port);

            //获取输入字符流
            reader = new BufferedReader(new InputStreamReader(
                    socket.getInputStream()
            ));

            //获取输出字符流
            writer = new BufferedWriter(new OutputStreamWriter(
                    socket.getOutputStream()
            ));

            //获取输入字符流
            BufferedReader scan = new BufferedReader(new InputStreamReader(System.in));

            while (true) {
                String msg = scan.readLine();

                //向服务器发送消息
                writer.write(msg + "\n");
                writer.flush();
			   
                //接收消息
                String line = reader.readLine();
                System.out.println("server：" + line);

                if (msg.equals(QUIT)) {
                    break;
                }
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(writer != null) {
                try {
                    writer.close();
                    System.out.println("Client close!");
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }
}

服务端：

package com.xiaojie.net;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * @author Mrli
 * @date 2020/9/25 19:37
 */
public class Server {
    public static void main(String[] args) {
        final int port = 6767;
        final String QUIT = "quit";
        ServerSocket serverSocket = null;

        try {
            serverSocket = new ServerSocket(port);
            System.out.println("服务器已启动，监听端口：" + port);

            while(true) {
                Socket accept = serverSocket.accept();
                System.out.println("客户端" + accept.getPort() + ":" + "已经连接");

                //获取输入字符流
                BufferedReader reader = new BufferedReader(new InputStreamReader(
                        accept.getInputStream()
                ));
                //获取输出字符流
                BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(
                        accept.getOutputStream()
                ));

                String msg = null;
                while ((msg = reader.readLine()) != null ) {
                    //接收消息
                    System.out.println("client[" + accept.getPort() + "]:" +msg);
                    
                    //转发到Client,
                    writer.write( msg + "\n");
                    writer.flush();

                    if(msg.equals(QUIT)) {
                        System.out.println("client close!");
                        break;
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(serverSocket != null) {
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

运行结果：

client端：

服务端：

BIO学习到这里，后面IO学习继续更新！