Java网络编程：TCP/IP通信示例

原创爱被打了一巴掌 2024-10-11 14:48 34阅读 0赞

在Java中，我们可以使用java.net包来实现TCP/IP通信。以下是一个简单的TCP客户端和服务器示例：

1. **客户端示例**（ServerSocket用于监听，Socket用于与服务器通信）

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

public class Client {
    public static void main(String[] args) {
        // 创建Socket对象
        try (Socket socket = new Socket("localhost", 1234)) {
            // 获取输出流
            OutputStream outputStream = socket.getOutputStream();
            
            // 发送数据（这里发送一个字符串）
            String message = "Hello, Server!";
            byte[] bytes = message.getBytes("UTF-8");
            outputStream.write(bytes);
            
            // 关闭输出流
            outputStream.close();
            
            // 关闭Socket连接
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
```

2. **服务器示例**（ServerSocket用于监听，Socket用于与客户端通信）

```java
import 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 listening on port 1234...");

// 等待客户端连接
            Socket clientSocket = serverSocket.accept();
            
            System.out.println("Client connected from IP: " + clientSocket.getInetAddress().getHostAddress());

// 创建输出流和输入流
            OutputStream outputStream = clientSocket.getOutputStream();
            InputStream inputStream = clientSocket.getInputStream();

// 与客户端通信（这里接收一个字符串）
            String messageFromClient = readInputStream(inputStream);
            System.out.println("Server received message: " + messageFromClient);

// 发送消息给客户端
            byte[] bytesToClient = "Hello, Client!".getBytes("UTF-8");
            outputStream.write(bytesToClient);
            
            // 关闭输出流和输入流
            outputStream.close();
            inputStream.close();

// 关闭Socket连接
            clientSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

private static String readInputStream(InputStream inputStream) throws IOException {
        StringBuilder sb = new StringBuilder();
        byte[] buffer = new byte[1024];
        while (true) {
            int numRead = inputStream.read(buffer);
            if (numRead == -1) break; // reached end of file
            sb.append(new String(buffer, 0, numRead))));
        }
        return sb.toString();
    }
}
```

这些示例展示了如何在Java中使用TCP/IP通信。客户端发送数据到服务器，服务器接收并回复客户端。