用java写Smart-Socket 实现 upd clent

Smart-Socket 是一个基于Java语言的网络编程库，可以用来实现UDP客户端。下面是一个简单的示例代码：

import java.net.*;

public class UDPSocketClient {
    public static void main(String[] args) throws Exception {
        // 创建一个UDP Socket
        DatagramSocket socket = new DatagramSocket();

        // 发送数据
        String message = "Hello, world!";
        InetAddress address = InetAddress.getByName("127.0.0.1");
        int port = 8888;
        byte[] buffer = message.getBytes();
        DatagramPacket packet = new DatagramPacket(buffer, buffer.length, address, port);
        socket.send(packet);

        // 接收数据
        byte[] receiveBuffer = new byte[1024];
        DatagramPacket receivePacket = new DatagramPacket(receiveBuffer, receiveBuffer.length);
        socket.receive(receivePacket);
        String receiveMessage = new String(receivePacket.getData(), 0, receivePacket.getLength());
        System.out.println("Receive message: " + receiveMessage);

        // 关闭Socket
        socket.close();
    }
}

这个示例程序使用 `DatagramSocket` 类创建了一个UDP Socket，并且发送了一个消息到指定的IP地址和端口号。然后等待接收服务器返回的消息，并打印出来。最后关闭Socket。