DatagramSocket编程实例

 

TCP协议客户端和服务器端的套接字为Socket和ServerSocket 

UDP协议的客户端和服务器端的套接字为DatagramSocket 

以下为DatagramSocket发送和接收的实例

 

 

Server代码：

import java.io.IOException;import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.InetAddress;import java.net.SocketException;import java.net.UnknownHostException;import java.util.Date;import java.util.Timer;import java.util.TimerTask;public class DGSServer {static DatagramSocket s = null;/** * 本例使用定时器定时发送，每5秒发送一次。若不想用定时器，可将run方法下的代码复制放到main中即可。 */public static void main(String[] args) {// TODO Auto-generated method stubSystem.out.println("Server starting .../n");try {s = new DatagramSocket();Timer timer = new Timer();timer.scheduleAtFixedRate(new TimerTask(){@Overridepublic void run() {// TODO Auto-generated method stubbyte[] buffer = new String("send to client。。。/n").getBytes();InetAddress ia;try {//改为客户机IP，若本机发送，用localhost即可String host = "localhost";ia = InetAddress.getByName(host);DatagramPacket dgp2 = new DatagramPacket(buffer,buffer.length,ia,10000);//发送dgp2s.send(dgp2);//延时1秒发送dgp3DatagramPacket dgp3 = new DatagramPacket("message----end".getBytes(),"message----end".getBytes().length,ia,10000);Thread.sleep(1000);s.send(dgp3);} catch (UnknownHostException e1) {// TODO Auto-generated catch blocke1.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}, new Date(System.currentTimeMillis()), 5*1000);} catch (SocketException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}} 

 

Client代码：

import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; import java.net.SocketException; import java.net.UnknownHostException; public class DGSClient { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub String host = "localhost"; DatagramSocket socket = null; StringBuffer sb = new StringBuffer(); try { socket = new DatagramSocket(10000);//端口号 InetAddress ia = InetAddress.getByName(host); while(true){ byte[] buffer = new byte[1024]; DatagramPacket dgp = new DatagramPacket(buffer,buffer.length); socket.receive(dgp); String str = new String(dgp.getData()); System.out.println(str); sb.append(str.trim()); if(str.indexOf("----end")>=0){//接收到----end为一整句 System.out.println("原始信息："+ sb.toString()); sb = new StringBuffer(); } } } catch (SocketException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (UnknownHostException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { if(socket != null){ socket.close(); } } } }