Java Socket编程常见错误：连接断开示例

原创蔚落 2024-10-07 20:06 67阅读 0赞

在JavaSocket编程中，连接断开是常见的问题。下面是一个简单的示例：

1. 创建Socket服务器端代码（Server.java）：

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

public class Server {
    public static void main(String[] args) {
        try (ServerSocket serverSocket = new ServerSocket(8080)); 
        do {
            Socket clientSocket = serverSocket.accept();
            
            System.out.println("Connection accepted from " + clientSocket.getRemoteSocketAddress()));
            
            // 创建一个线程来处理客户端
            Thread clientThread = new Thread(() -> handleClient(clientSocket)));
            clientThread.start();
        } while (true);
    }

private static void handleClient(Socket socket) {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()))); 
        { 
            String inputLine;
            System.out.println("Client is sending data...");

while ((inputLine = br.readLine()) != null) {
                System.out.println("Received: " + inputLine);
                
                // 这里可以根据需求进行数据处理
                processData(inputLine);
            }
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("Error handling client data: " + e.getMessage());
        }
    }

private static void processData(String inputLine) {
        // 这里是示例，你可以根据实际需求进行处理
        System.out.println("Processing data: " + inputLine.toUpperCase());

// 如果需要回复客户端，可以在这里生成响应数据
        String response = "Processed data: " + inputLine;
        sendResponse(response, socket);
    }

private static void sendResponse(String response, Socket socket) {
        try (PrintWriter writer = new PrintWriter(socket.getOutputStream(), true)); 
        {
            writer.println("Server's response: " + response);
            
            System.out.println("Sent response to client: " + response);
        }
        catch (IOException e) {
            e.printStackTrace();
            System.out.println("Error sending response to client: " + e.getMessage());
        }
    }
}
```

2. 创建Socket客户端代码（Client.java）：

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

public class Client {
    public static void main(String[] args) throws IOException {
        String serverAddress = "localhost"; // 服务器地址，这里默认为本地
        int serverPort = 8080; // 服务器端口，这里设置为示例的端口

Socket socket = new Socket(serverAddress, serverPort));
        
        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())));

System.out.println("Connecting to server at " + serverAddress + ":" + serverPort);

String inputLine;
        while ((inputLine = in.readLine()) != null) {
            System.out.println("Received from server: " + inputLine));
            
            // 这里可以将输入的行进行处理
            // 例如，发送数据给服务器
            processInput(inputLine);
        }

socket.close();
    }

private static void processInput(String inputLine) {
        // 示例：将收到的数据作为用户名发送给服务器
        String username = inputLine; // 这里可以根据实际需求生成用户名

// 创建一个字符串，用于构建发送到服务器的请求数据
        StringBuilder requestBuilder = new StringBuilder("Login: " + username + "\n");

// 发送请求数据到服务器
        sendRequest(requestBuilder.toString(), serverAddress, serverPort));
    }

private static void sendRequest(String requestData, String serverAddress, int serverPort) throws IOException {
        Socket socket = new Socket(serverAddress, serverPort));

BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())));

System.out.println("Sending request to server: " + requestData);

writer.write(requestData);
        writer.newLine(); // 添加新行，以确保请求数据被正确处理
        writer.flush();

socket.close();
    }
}
```

3. 运行客户端和服务器代码。

当你在客户端运行`Client.java`脚本时，它将连接到指定的服务器地址和端口，并与服务器进行交互。同时，在服务器端运行`Server.java`脚本，它将作为服务器监听客户端连接并提供服务。