개발새발 IT

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.Inet4Address;

import java.net.InetAddress;

import java.util.Random;

public class dailyCode{

public static void main(String[] args){

try {

// InetAddress addr = Inet4Address.getByName("0.0.0.0");

InetAddress addr = Inet4Address.getLocalHost();

Random ran = new Random();

int port = ran.nextInt(65535) + 0;

System.out.println("ip = " + addr + " port = " + port);

DatagramSocket socket = new DatagramSocket(port, addr);

System.out.println("getLocalAddress = " + socket.getLocalAddress() + " getLocalPort = " + socket.getLocalPort());

System.out.println("getInetAddress = " + socket.getInetAddress() + " getLocalSocketAddress = " + socket.getLocalSocketAddress());

System.out.println("getRemoteSocketAddress = " + socket.getRemoteSocketAddress() + " getReuseAddress = " + socket.getReuseAddress());

String str = "111";

DatagramPacket sendPacket = new DatagramPacket(str.getBytes(), str.getBytes().length, addr, port);

String msg = new String(sendPacket.getData(), 0, sendPacket.getLength());

System.out.println("To Server : " + msg);

socket.send(sendPacket);

DatagramPacket receivePacket = new DatagramPacket(str.getBytes(), str.getBytes().length);

socket.receive(receivePacket);

msg = new String(receivePacket.getData(), 0, receivePacket.getLength());

System.out.println("From Client : " + msg);

} catch (Exception e) {

e.printStackTrace();

}

}

}