java实现udp通信客户端代码

以下是一个简单的Java UDP客户端示例代码：

import java.net.*;

public class UDPClient {
    public static void main(String[] args) throws Exception {
        DatagramSocket clientSocket = new DatagramSocket();

        InetAddress IPAddress = InetAddress.getByName("localhost");

        byte[] sendData = new byte[1024];
        byte[] receiveData = new byte[1024];

        String sentence = "Hello UDP Server!";
        sendData = sentence.getBytes();

        DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
        clientSocket.send(sendPacket);

        DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
        clientSocket.receive(receivePacket);

        String modifiedSentence = new String(receivePacket.getData());
        System.out.println("FROM SERVER:" + modifiedSentence);

        clientSocket.close();
    }
}

这段代码创建了一个DatagramSocket对象作为客户端套接字，然后通过InetAddress对象获取本地主机地址。接下来，我们将要发送的字符串转换为字节数组，并将其发送到指定的服务器地址和端口号。最后，客户端等待接收来自服务器的响应，并将其打印在控制台上。