Java中修改TCP通信代码实现BufferedReader读取至stopp终止的问题

修改后的客户端代码 #

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

public class Klient {
    public static void main(String[] args) throws UnknownHostException, IOException {
        String sentence;
        String modifiedSentence;
        BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
        Socket clientSocket = new Socket("127.0.0.1", 6789);
        DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
        BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

        while (true) {
            sentence = inFromUser.readLine();
            // 处理输入为空或终止指令
            if (sentence == null || "stopp".equalsIgnoreCase(sentence)) {
                outToServer.writeBytes("stopp\n");
                clientSocket.close();
                break;
            }
            outToServer.writeBytes(sentence + '\n');
            modifiedSentence = inFromServer.readLine();
            System.out.println(modifiedSentence);
        }
    }
}

客户端修改点 #

• 添加终止条件：当输入stopp（不区分大小写）或输入流结束（sentence为null）时，发送终止指令给服务器，关闭Socket并退出循环。
• 确保资源正常释放，避免连接泄漏。

修改后的服务器代码 #

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

public class TCPServer {
    public static void main(String[] args) throws IOException {
        String clientSentence;
        String capitalizedSentence;
        ServerSocket welcomeSocket = new ServerSocket(6789);
        
        Socket connectionSocket = welcomeSocket.accept();
        BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
        DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());

        while (true) {
            clientSentence = inFromClient.readLine();
            // 判断是否收到终止指令或客户端断开
            if (clientSentence == null || "stopp".equalsIgnoreCase(clientSentence)) {
                connectionSocket.close();
                welcomeSocket.close();
                break;
            }
            capitalizedSentence = clientSentence.toUpperCase() + '\n';
            outToClient.writeBytes(capitalizedSentence);
        }
    }
}

服务器修改点 #

• 移除原外层无限循环，改为接受单个客户端连接后进入消息处理循环（若需支持多客户端，可将连接处理逻辑放入线程）。
• 添加终止判断：收到stopp指令或客户端断开时，关闭连接和ServerSocket，终止服务器程序。
• 持续读取客户端发送的消息，直到触发终止条件。

内容的提问来源于stack exchange，提问作者brah79