Offline_Nov-17_Zahin_Server

/**
 * Created by Zahin on 11/17/2016.
 */
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.net.BindException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.Socket;
import java.net.SocketException;
import java.util.Hashtable;
import java.util.Scanner;
import java.util.StringTokenizer;



public class Server {
    public static void main(String[] args) {
        String via="CSE108_NetworkingAssignmentServer";
        DatagramSocket socketReceiver;
        DatagramSocket socketSender;
        DatagramPacket receivingPack;
        DatagramPacket sendingPack;
        String[] strArray= new String[4];
        Hashtable<String,User> table=null;
        int counter1=0;
        int counter2=0;
        try{
            socketReceiver = new DatagramSocket(1202);
            socketSender = new DatagramSocket();
            receivingPack = new DatagramPacket(new byte[1024], 1024);
            while(true){
                socketReceiver.receive(receivingPack);

                byte[] receivedData= receivingPack.getData();
                String str1 = new String(receivedData);
                InetAddress IPAddress = receivingPack.getAddress();
                int port = receivingPack.getPort();
                StringTokenizer st= new StringTokenizer(str1," ");
                while (st.hasMoreTokens()) {
                    strArray[counter1]=st.nextToken();
                    counter1++;
                }
                if (strArray[0].equals(via)== false) {
                    System.out.println("Warning: Server name mismatch. Message dropped.");
                }
                else if (strArray[0].equals(via)== true && !table.containsKey(strArray[1]) ){
                    System.out.println("Warning: Unknown recipient. Message dropped.");
                    //ip ar port er condition add korte hobe

                }
                else if(strArray[0].equals(via)== true && strArray[1].equals(via)== true )  {
                    int portR= Integer.parseInt(strArray[3]);
                    User user = new User(portR,IPAddress) ;
                    table.put(strArray[2],user);

                }
                else if(strArray[0].equals(via)== true && strArray[1].equals(via)== false && table.containsKey(strArray[1])  )  {
                    byte[] sendingData = strArray[3].getBytes();
                    sendingPack =new DatagramPacket(sendingData, sendingData.length, IPAddress, port);
                    socketSender.send(sendingPack);

                }


                System.exit(0);
            }





        } catch (SocketException e1) {
            e1.printStackTrace();
        } catch (IOException e1) {
            e1.printStackTrace();
        }

    }catch(SocketException e) {
            e.printStackTrace();
        }
    }
}