使用Java处理网络异常：Socket关闭问题实例

原创 Bertha 。 2024-11-07 04:42 7阅读 0赞

在Java中处理网络异常，特别是Socket关闭问题，通常涉及到捕获和处理`IOException`。下面是一个简单的示例，展示如何在Java中创建一个客户端和服务器，以及如何处理Socket关闭时可能抛出的异常。

###服务器端代码示例```javaimport java.io.*;
import java.net.*;

public class Server {
 public static void main(String[] args) {
 try (ServerSocket serverSocket = new ServerSocket(1234)) {
 System.out.println("Server is running and waiting for client connection...");

//等待客户端连接Socket clientSocket = serverSocket.accept();
 System.out.println("Client connected.");

// 获取输入输出流 BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
 PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);

//读取客户端发送的消息String inputLine;
 while ((inputLine = in.readLine()) != null) {
 System.out.println("Client says: " + inputLine);
out.println("Echo: " + inputLine);
 }

} catch (IOException e) {
 System.out.println("Exception caught when trying to listen on port or listening for a connection");
 System.out.println(e.getMessage());
 }
 }
}
```###客户端代码示例```javaimport java.io.*;
import java.net.*;

public class Client {
 public static void main(String[] args) {
 try (Socket socket = new Socket("localhost",1234)) {
 System.out.println("Connected to server.");

// 获取输入输出流 PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
 BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
 BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));

String userInput;
 while ((userInput = stdIn.readLine()) != null) {
out.println(userInput);
 System.out.println("Server response: " + in.readLine());
 }

} catch (UnknownHostException e) {
 System.err.println("Don't know about host " + "localhost");
 System.exit(1);
} catch (IOException e) {
 System.out.println("Couldn't get I/O for the connection to " + "localhost");
 System.exit(1);
 }
 }
}
```###异常处理在上述代码中，我们使用了`try-with-resources`语句来自动关闭`Socket`、`ServerSocket`、`BufferedReader`和`PrintWriter`。这样做可以确保即使发生异常，这些资源也会被正确关闭。

- `IOException`：当Socket连接出现问题时，比如连接被关闭或者网络中断，会抛出这个异常。
- `UnknownHostException`：如果客户端尝试连接到一个未知的主机，会抛出这个异常。

在实际应用中，你可能需要根据具体的业务逻辑来决定如何处理这些异常。例如，你可能需要重试连接，记录日志，或者通知用户连接失败。