public class Udps { //接收端 

public static void main(String[] args) throws IOException { 

//1.准备接收数据报的箱子

byte[] by = new byte[1024];

DatagramPacket dp = new DatagramPacket(by,by.length); 

//2创建套接字，绑定到相应的端口去接收数据报

DatagramSocket ds = new DatagramSocket(8803); 

//3.接收数据报

ds.receive(dp); 

//4.处理操作接收到的数据4属性

System.out.println(new String(dp.getData(),0,dp.getLength())+dp.getPort()+dp.getSocketAddress()); 

//5.准备反馈的信息，及基本属性

String replay = "我是服务器，欢迎登录！";

SocketAddress ia = dp.getSocketAddress(); 

//6将要发送的数据装箱

DatagramPacket dpr = new DatagramPacket(replay.getBytes(),replay.getBytes().length,ia); 

//7.发送信息

ds.send(dpr); 

//8.关闭套接字

ds.close();

} 

}

public class Udpc { //发送端

public static void main(String[] args) throws IOException {

//1准备要发送的数据内容

String send = "我是客户端，我请求登录！";

//2创建装箱包

DatagramPacket dp = new DatagramPacket(send.getBytes(),send.getBytes().length,InetAddress.getLocalHost(),8803);

//3创建套接字端口发送数据报

DatagramSocket ds = new DatagramSocket();

//4.发送数据

ds.send(dp);

//5准备接受返回的信息

byte[] by = new byte[1024];

//6.准备接受的装箱的包

DatagramPacket dpr =new DatagramPacket(by,by.length); 

//7接受信息

ds.receive(dpr); 

//8处理接受到的信息4属性

System.out.println(new String(dpr.getData(),0,dpr.getLength())+dpr.getPort()+dpr.getSocketAddress());

//关闭套接字

ds.close();

}

}