创建UDP客户端和服务器

import java.net.*;

/* 
*来 自
 n o w j a v a . c o m
*/

class WriteServer {

     public static int serverPort     = 1234;

     public static int clientPort     = 1235;

     public static int buffer_size     = 1024;


     public static DatagramSocket ds;

     public static byte buffer[] = new byte[buffer_size];


     // UDP Server Method

     public static void TheServer() throws Exception {

          int pos = 0;

          while(true) {

               int c = System.in.read();

               switch (c) {

                    case -1:

                         System.out.println("Server Quits!!");

                         return;

                    case '\r':

                         break;
                         /**
                         n o w j a v a . c o m - 时  代  Java 提供 
                         **/

                    case '\n':

                         ds.send(new DatagramPacket(buffer, pos, InetAddress.getLocalHost(),clientPort));

                         pos = 0;

                         break;

                    default:

                         buffer[pos++] = (byte) c;

               }

          }

     }


     // UDP Client Method

     public static void TheClient() throws Exception {

          while (true) {

               DatagramPacket p = new DatagramPacket(buffer, buffer.length);

               ds.receive(p);

               System.out.println(new String(p.getData(), 0, p.getLength()));

          }

     }


     public static void main(