udp_socket_server.java

JAVA的高级应用以及网络编程

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


public class UDP_socket_server
{
  static final int INPORT = 1711;
  private byte[] buf = new byte[1000];
  private DatagramPacket dp =new DatagramPacket(buf, buf.length);
  private DatagramSocket socket;
  public UDP_socket_server()
  {
    try
    {
      socket = new DatagramSocket(INPORT);
      System.out.println("Server started");
      while(true)
      {
        socket.receive(dp);
        String rcvd = DataGram.toString(dp) + ", from address: " + dp.getAddress() + ", port: " + dp.getPort();
        System.out.println(rcvd);
        String echoString = "Echoed: " + rcvd;
        DatagramPacket echo = DataGram.toDatagram(echoString,dp.getAddress(), dp.getPort());
        socket.send(echo);
      }
    }
    catch(SocketException e)
    {
      System.err.println("Can't open socket");
      System.exit(1);
    }
    catch(IOException e)
    {
      System.err.println("Communication error");
      e.printStackTrace();
    }
  }
  public static void main(String[] args)
  {
    new UDP_socket_server();
  }
}