Java网络编程基础：客户端和服务端通信案例

原创谁践踏了优雅 2024-11-30 22:00 44阅读 0赞

在Java中进行网络编程，通常会使用Socket或者NIO等API。下面将通过两个简单的案例来说明客户端和服务端的通信过程。

1. **TCP客户端发送消息到服务端**：

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

public class Client {
    public static void main(String[] args) {
        // 创建客户端连接
        try (Socket socket = new Socket("localhost", 8080); 
             BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream())))) {

System.out.println("Client: Send message...");

String msg = "Hello, Server!"; // Message to send

// Write message to output stream
            in.write(msg.getBytes());
            
            // Wait for server to acknowledge the message
            System.out.println("Client: Waiting for response...");

String response = in.readLine(); // Read server's response

if (response != null) {
                System.out.println("Server Response: " + response);
            } else {
                System.out.println("No response received from server.");
            }
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("Error connecting to server.");
        }
    }
}
```

2. **服务端接收并响应客户端的消息**：

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

public class Server {
    public static void main(String[] args) {
        // 创建服务器端连接
        try (ServerSocket socket = new ServerSocket(8080); 
             Socket clientSocket = socket.accept(); 
             PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true));) {

System.out.println("Server: Waiting for client connection...");

// 接收客户端发送的消息
            String messageFromClient = in.readLine();

if (messageFromClient != null) {
                System.out.println("Server: Received message from client: " + messageFromClient);

// 发送响应消息给客户端
                out.println("Server Response: Hello, Client! Your message has been received.");
            } else {
                System.out.println("Server: No message received from client.");
            }
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("Error accepting client connection.");
        }
    }
}
```

以上两个案例展示了客户端和服务端之间的基本通信过程。在实际项目中，通信协议会更复杂，并且可能会涉及到线程、多任务处理等高级概念。