UDP connection object principle analysis and usage examples

package udp; 
 
import java.net.*; 
 
/** 
 * @Description UDP client program, used to send data to the server and receive the server's response information* @author cuisuqiang 
 * @version 1.0 
 * @since <a href="mailto:[email protected]" rel="external nofollow" >[email protected]</a> 
 */ 
public class UdpClientSocket { 
  /** 
   * Connection object */ 
  private static DatagramSocket ds = null; 
  /** 
   * Address object */ 
  private static SocketAddress address = null; 
   
  /** 
   * Test the client's method of sending packets and receiving response information*/ 
  public static void main(String[] args) throws Exception { 
    init(); 
    while(true){ 
      UdpClientSocket.send(address,"Hello, dear!".getBytes()); 
      UdpClientSocket.receive(); 
      try { 
        Thread.sleep(3 * 1000); 
      } catch (Exception e) { 
        e.printStackTrace(); 
      } 
    } 
  } 
   
  /** 
   * Initialize the connection and address */ 
  public static void init(){ 
    try { 
      ds = new DatagramSocket(8899); // Bind to local port as client ds.setSoTimeout(2 * 1000); 
      address = new InetSocketAddress("127.0.0.1",3344); 
    } catch (Exception e) { 
      e.printStackTrace(); 
    } 
  } 
   
  /** 
   * Send data information to the specified server */ 
  public static void send(SocketAddress address,byte[] bytes){ 
    try { 
      DatagramPacket dp = new DatagramPacket(bytes, bytes.length, address); 
      ds.send(dp); 
    } catch (Exception e) { 
      e.printStackTrace(); 
    } 
  } 
 
  /** 
   * Receive data sent back from the specified server*/ 
  public static void receive(){ 
    try { 
      byte[] buffer = new byte[1024]; 
      DatagramPacket dp = new DatagramPacket(buffer, buffer.length); 
      ds.receive(dp);    
      byte[] data = new byte[dp.getLength()]; 
      System.arraycopy(dp.getData(), 0, data, 0, dp.getLength());  
      System.out.println("Server response data: " + new String(data)); 
    } catch (Exception e) { 
      e.printStackTrace(); 
    } 
  } 
}

package udp;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketAddress;

/**
 * @Description of UDP service class * @author cuisuqiang
 * @version 1.0
 * @since [email protected]
 */
public class UdpServerSocket {
	
	private static DatagramSocket ds = null;
	private static SocketAddress address = null;
	
	/**
	 * Test method */
	public static void main(String[] args) throws Exception {
		init();
		System.out.println("---->Service starts listening!<----");
		while (true) {
			UdpServerSocket.receive();
			UdpServerSocket.response(address,"Hello, have you eaten?");
		}		
	}
	
	public static void init(){
		try {
			ds = new DatagramSocket(3344);
			ds.setSoTimeout(0);
			address = new InetSocketAddress("127.0.0.1",8899);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * Receive data packets. This method will cause thread blocking */
	public static void receive() {
		try {
			byte[] buffer = new byte[1024];
			DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
			ds.receive(packet);
			String info = new String(packet.getData(), 0, packet.getLength());
			System.out.println("Receive information: " + info);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * Send the response packet to the requester */
	public static void response(SocketAddress address,String info){
		try {
			DatagramPacket dp = new DatagramPacket(info.getBytes(), info.getBytes().length, address);
			dp.setData(info.getBytes());
			ds.send(dp);
		} catch (Exception e) {
			e.printStackTrace();
		}		
	}
}