Java笔记二十三.网络编程基础与UDP编程

<span style="font-size:18px;">import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
/*UDP发送端*/
public class udpSender {
 public static void main(String[] args)
 {
  try
  {
   String string = "I Love China.";
   //1.创建发送端应用程序Socket
   DatagramSocket socket = new DatagramSocket();
   //2.创建一个DatagramPacket"集装箱"
   DatagramPacket p = new DatagramPacket(string.getBytes(),	 //将要发送的数据(字节形式)
                   string.length()	 //数据长度
                   ,InetAddress.getByName("192.168.1.100")	//目标IP(本机)
                   , 3000);	 //应用程序端口
   socket.send(p);	//发送数据(字节数组、目标IP、应用端口号)
   socket.close(); //关闭socket，释放资源
  }
  catch (Exception e)
  {
   e.printStackTrace();
  }
 
 }
}

</span>

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
/*接收数据网络应用*/
public class udpReceiver {
 public static void main(String[] args)
 {
  //1.创建Socket并指定应用程序的端口号(3000)
  try
  {
   DatagramSocket socket = new DatagramSocket(3000);
   byte[] buf = new byte[1024];
   DatagramPacket dp = new DatagramPacket(buf, 1024);
   socket.receive(dp);	 //通过Socket从网络中获取数据并存放至字节数组buf中
   System.out.println(new String(dp.getData(),0,dp.getLength())+"from "
          +dp.getAddress().getHostAddress()+":"+dp.getPort());
  }
  catch (Exception e)
  {
   e.printStackTrace();
  }
 }
}