基于TCP实现聊天

TCP客户端代码

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

public class TcpClientDemo01 {

    public static void main(String[] args) {
        Socket socket = null;
        OutputStream os = null;
        InputStream is = null;
        BufferedReader reader = null;

        try {
            // 1. 要知道服务器的地址、端口号
            InetAddress serverIP = InetAddress.getByName("127.0.0.1");
            int port = 9999;

            // 2. 创建一个Socket连接
            socket = new Socket(serverIP, port);

            // 3. 创建输出流，用于发送消息给服务器
            os = socket.getOutputStream();
            PrintWriter pw = new PrintWriter(os, true);

            // 4. 创建输入流，用于接收服务器的消息
            is = socket.getInputStream();
            BufferedReader br = new BufferedReader(new InputStreamReader(is));

            // 5. 客户端输入消息
            reader = new BufferedReader(new InputStreamReader(System.in));
            String clientMessage;
            String serverResponse;

            while (true) {
                // 读取客户端输入的消息
                System.out.print("客户端: ");
                clientMessage = reader.readLine();

                // 发送消息到服务器
                pw.println(clientMessage);

                // 接收服务器返回的消息
                serverResponse = br.readLine();
                System.out.println("服务器: " + serverResponse);

                // 判断是否退出
                if ("bye".equalsIgnoreCase(clientMessage)) {
                    break;
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            try {
                if (reader != null) reader.close();
                if (is != null) is.close();
                if (os != null) os.close();
                if (socket != null) socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

TCP服务器代码

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

public class TcpServerDemo01 {

    public static void main(String[] args) {
        ServerSocket serverSocket = null;
        Socket socket = null;
        InputStream is = null;
        OutputStream os = null;
        BufferedReader br = null;

        try {
            // 1. 创建一个服务器端的Socket，绑定端口9999
            serverSocket = new ServerSocket(9999);

            // 2. 等待客户端连接
            System.out.println("服务器等待连接...");
            socket = serverSocket.accept();
            System.out.println("客户端已连接！");

            // 3. 获取客户端发送的消息
            is = socket.getInputStream();
            br = new BufferedReader(new InputStreamReader(is));

            // 4. 创建输出流，发送消息给客户端
            os = socket.getOutputStream();
            PrintWriter pw = new PrintWriter(os, true);

            String clientMessage;
            String serverMessage;

            while (true) {
                // 读取客户端发送的消息
                clientMessage = br.readLine();
                System.out.println("客户端: " + clientMessage);

                // 判断是否退出
                if ("bye".equalsIgnoreCase(clientMessage)) {
                    pw.println("再见！");
                    break;
                }

                // 服务器回复消息
                BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
                System.out.print("服务器: ");
                serverMessage = reader.readLine();

                // 发送回复给客户端
                pw.println(serverMessage);
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            try {
                if (br != null) br.close();
                if (is != null) is.close();
                if (os != null) os.close();
                if (socket != null) socket.close();
                if (serverSocket != null) serverSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}