Java のネットワーク プログラミング関数を使用してネットワーク通信とデータ送信を行う方法

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

public class TCPClient {
    public static void main(String[] args) {
        try {
            // 创建Socket对象，指定服务器的IP地址和端口号
            Socket socket = new Socket("127.0.0.1", 8888);

            // 创建输入流和输出流
            OutputStream out = socket.getOutputStream();
            InputStream in = socket.getInputStream();

            // 发送数据到服务器
            String message = "Hello, Server!";
            out.write(message.getBytes());

            // 接收服务器返回的数据
            byte[] buffer = new byte[1024];
            int length = in.read(buffer);

            // 关闭连接
            socket.close();

            // 输出接收到的数据
            System.out.println("Message from server: " + new String(buffer, 0, length));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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


public class TCPServer {
    public static void main(String[] args) {
        try {
            // 创建ServerSocket对象，监听指定的端口号
            ServerSocket serverSocket = new ServerSocket(8888);

            // 等待客户端的连接
            Socket socket = serverSocket.accept();

            // 创建输入流和输出流
            InputStream in = socket.getInputStream();
            OutputStream out = socket.getOutputStream();

            // 接收客户端发送的数据
            byte[] buffer = new byte[1024];
            int length = in.read(buffer);

            // 处理数据
            String message = new String(buffer, 0, length);
            System.out.println("Message from client: " + message);

            // 发送数据到客户端
            String response = "Hello, Client!";
            out.write(response.getBytes());

            // 关闭连接
            socket.close();
            serverSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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

public class UDPClient {
    public static void main(String[] args) {
        try {
            // 创建DatagramSocket对象
            DatagramSocket socket = new DatagramSocket();

            // 创建发送数据包
            String message = "Hello, Server!";
            DatagramPacket packet = new DatagramPacket(message.getBytes(), message.length(), InetAddress.getByName("127.0.0.1"), 8888);

            // 发送数据包
            socket.send(packet);

            // 创建接收数据包
            byte[] buffer = new byte[1024];
            DatagramPacket receivePacket = new DatagramPacket(buffer, buffer.length);

            // 接收服务器返回的数据包
            socket.receive(receivePacket);

            // 关闭连接
            socket.close();

            // 输出接收到的数据
            String response = new String(receivePacket.getData(), 0, receivePacket.getLength());
            System.out.println("Message from server: " + response);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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

public class UDPServer {
    public static void main(String[] args) {
        try {
            // 创建DatagramSocket对象，指定端口号
            DatagramSocket socket = new DatagramSocket(8888);

            // 创建接收数据包
            byte[] buffer = new byte[1024];
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length);

            // 接收客户端发送的数据包
            socket.receive(packet);

            // 处理数据
            String message = new String(packet.getData(), 0, packet.getLength());
            System.out.println("Message from client: " + message);

            // 发送数据包给客户端
            String response = "Hello, Client!";
            DatagramPacket responsePacket = new DatagramPacket(response.getBytes(), response.length(), packet.getAddress(), packet.getPort());
            socket.send(responsePacket);

            // 关闭连接
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}