Socket TCP牛刀小试

叁歲伎倆 2023-06-06 12:30 1阅读 0赞

> 浏览器和服务器如何通过Socket来连接，本文模拟Sock TCP客户端和服务端的连接，用Java代码实现这个简单的功能

## 客户端 ##

import java.io.*;
    import java.net.Inet4Address;
    import java.net.InetSocketAddress;
    import java.net.Socket;
    
    public class Client {
        public static void main(String[] args) throws IOException {
            Socket socket = new Socket();
            // 超时时间
            socket.setSoTimeout(3000);
    
            // 连接本地，端口2000；超时时间3000ms
            socket.connect(new InetSocketAddress(Inet4Address.getLocalHost(), 2000), 3000);
    
            System.out.println("已发起服务器连接，并进入后续流程～");
            System.out.println("客户端信息：" + socket.getLocalAddress() + " P:" + socket.getLocalPort());
            System.out.println("服务器信息：" + socket.getInetAddress() + " P:" + socket.getPort());
    
            try {
                // 发送接收数据
                todo(socket);
            } catch (Exception e) {
                System.out.println("异常关闭");
            }
    
            // 释放资源
            socket.close();
            System.out.println("客户端已退出～");
    
        }
    
        private static void todo(Socket client) throws IOException {
            // 构建键盘输入流
            InputStream in = System.in;
            BufferedReader input = new BufferedReader(new InputStreamReader(in));
    
    
            // 得到Socket输出流，并转换为打印流
            OutputStream outputStream = client.getOutputStream();
            PrintStream socketPrintStream = new PrintStream(outputStream);
    
    
            // 得到Socket输入流，并转换为BufferedReader
            InputStream inputStream = client.getInputStream();
            BufferedReader socketBufferedReader = new BufferedReader(new InputStreamReader(inputStream));
    
            boolean flag = true;
            do {
                // 键盘读取一行
                String str = input.readLine();
                // 发送到服务器
                socketPrintStream.println(str);
    
    
                // 从服务器读取一行
                String echo = socketBufferedReader.readLine();
                if ("bye".equalsIgnoreCase(echo)) {
                    flag = false;
                }else {
                    System.out.println(echo);
                }
            }while (flag);
    
            // 资源释放
            socketPrintStream.close();
            socketBufferedReader.close();
    
        }
    
    
    }

## 服务器 ##

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.PrintStream;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    public class Server {
        public static void main(String[] args) throws IOException {
            ServerSocket server = new ServerSocket(2000);
    
    
            System.out.println("服务器准备就绪～");
            System.out.println("服务器信息：" + server.getInetAddress() + " P:" + server.getLocalPort());
    
    
            // 等待客户端连接
            for (; ; ) {
                // 得到客户端
                Socket client = server.accept();
                // 客户端构建异步线程
                ClientHandler clientHandler = new ClientHandler(client);
                // 启动线程
                clientHandler.start();
            }
    
        }
    
        /**
         * 客户端消息处理
         */
        private static class ClientHandler extends Thread {
            private Socket socket;
            private boolean flag = true;
    
            ClientHandler(Socket socket) {
                this.socket = socket;
            }
    
            @Override
            public void run() {
                super.run();
                System.out.println("新客户端连接：" + socket.getInetAddress() +
                        " P:" + socket.getPort());
    
                try {
                    // 得到打印流，用于数据输出；服务器回送数据使用
                    PrintStream socketOutput = new PrintStream(socket.getOutputStream());
                    // 得到输入流，用于接收数据
                    BufferedReader socketInput = new BufferedReader(new InputStreamReader(
                            socket.getInputStream()));
    
                    do {
                        // 客户端拿到一条数据
                        String str = socketInput.readLine();
                        if ("bye".equalsIgnoreCase(str)) {
                            flag = false;
                            // 回送
                            socketOutput.println("bye");
                        } else {
                            // 打印到屏幕。并回送数据长度
                            System.out.println(str);
                            socketOutput.println("回送：" + str.length());
                        }
    
                    } while (flag);
    
                    socketInput.close();
                    socketOutput.close();
    
                } catch (Exception e) {
                    System.out.println("连接异常断开");
                } finally {
                    // 连接关闭
                    try {
                        socket.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
    
                System.out.println("客户端已退出：" + socket.getInetAddress() +
                        " P:" + socket.getPort());
    
            }
        }
    }

先启动服务器，再启动客户端，看看效果