java编程实现基于UDP协议传输数据的方法

import java.io.IOException; 
import java.net.DatagramPacket; 
import java.net.DatagramSocket; 
import java.net.SocketException; 
public class EchoServer { 
 private DatagramSocket datagramSocket; 
 private final int port = 8088; 
 public static void main(String[] args) throws SocketException { 
  new EchoServer().service(); 
 } 
 public EchoServer() throws SocketException{ 
  datagramSocket = new DatagramSocket(port); 
  System.out.println("服务器启动"); 
 } 
 public String echo(String msg){ 
  return "echo:"+msg; 
 } 
 public void service(){ 
  while (true) { 
   try { 
    DatagramPacket packet = new DatagramPacket(new byte[512], 512); 
    datagramSocket.receive(packet); 
    String msg = new String(packet.getData(), 0, packet.getLength()); 
    System.out.println(packet.getAddress()+"/"+packet.getPort()+" msg:"+msg); 
    packet.setData(echo(msg).getBytes()); 
    datagramSocket.send(packet); 
   } catch (IOException e) { 
    e.printStackTrace(); 
   } 
  } 
 } 
}

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStreamReader; 
import java.net.DatagramPacket; 
import java.net.DatagramSocket; 
import java.net.InetAddress; 
import java.net.SocketException; 
public class EchoClient { 
 private String remoteHost="localhost"; 
 private int remotePort=8088; 
 private DatagramSocket datagramSocket; 
 public EchoClient() throws SocketException{ 
  datagramSocket = new DatagramSocket(); 
 } 
 public static void main(String[] args) throws SocketException { 
  new EchoClient().talk(); 
 } 
 public void talk(){ 
  try { 
   BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); 
   String msg = null; 
   InetAddress address = InetAddress.getByName(remoteHost); 
   while ((msg=reader.readLine())!=null) { 
    //发送数据报 
    byte [] buffer = msg.getBytes(); 
    DatagramPacket packet = new DatagramPacket(buffer,buffer.length, address, remotePort); 
    datagramSocket.send(packet); 
    //接收数据报 
    DatagramPacket inputPacket = new DatagramPacket(new byte[512], 512); 
    datagramSocket.receive(inputPacket); 
    System.out.println(new String(inputPacket.getData(), 0 , inputPacket.getLength())); 
    if("bye".equals(msg)){ 
     break; 
    } 
   } 
  } catch (IOException e) { 
   e.printStackTrace(); 
  }finally{ 
   datagramSocket.close(); 
  } 
}