//  Server

import java.net.*;
import java.io.*;
import java.util.*;
class eserver implements Runnable
{

    Socket socket;
    int id;       
    int count;
    publicstaticvoid main(String args[])
    {
    int  count=0;
             try
        {
            ServerSocket s= new ServerSocket(13);

    while(true)
        {
            Socket socket=s.accept();
            eserver server=new eserver(socket,count);
            Thread t=new Thread(server);
            t.start();
        }
    }
        catch(Exception e)
        {
            System.out.println("Exception caught is::"+e);    
        }    
    }

            eserver(Socket sa,int i)
    { 
        socket=sa;
                 id=i;
        }

publicvoid run()
{
           int flag=0;StringTokenizer t;
           String id,ipAddress,str;   
           int i;
           try{     
                         InputStream is=socket.getInputStream();
        InputStreamReader isr=new InputStreamReader(is);
        BufferedReader br=new BufferedReader(isr);
                              
                        String cls=br.readLine();            

                           System.out.println("Client Requested : "+cls);  
                                      
                          if(cls.trim().equals("quit"))
                          {
             System.out.println("Client has Disconnected.....");
             br.close(); 
        }
         
                            
        try{ 
               OutputStream op=socket.getOutputStream();    
               PrintWriter pw=new PrintWriter(op);  
               String clientid=cls;
             
               String val="";
               String msg="";    

     FileReader fr=new FileReader("iptable.txt");
              BufferedReader bf=new BufferedReader(fr);              

              while(flag==0)
              {
               String b=bf.readLine();
                if(b==null) 
                break;

                t=new StringTokenizer(b);
                id=t.nextToken();
                ipAddress=t.nextToken();

               if(id.equals(clientid))  
      {

             System.out.println("URL          :: "+id);
             System.out.println("IP Address :: "+ipAddress);
                    val="*";flag=1;msg="URL="+id+" IP Address= "+ipAddress;
             }
  
               else
               {
           flag=0;msg="Sorry, Given URL is not Found.....";
               }
              
        }        
              
               bf.close();
     fr.close();

                  if(flag==1)                  
                  pw.println(msg);
                 else
                 pw.println(msg);  
                  pw.flush();
                  pw.close();


          }   //endtry2catch(Exception e)
        {
            System.out.println("Exception caught is::"+e);    
        }    
        
       }//endtry1catch(IOException e){}                
       
//end while 
       }//end run    

}

// Client 

import java.net.*;
import java.io.*;

publicclass eclient 
{

    
publicstaticvoid main(String args[])
    {
                String  instr,str;

                
         try{
         while(true)
          {
                   InetAddress address=InetAddress.getByName(null);
          System.out.println("\n\n==========================");    
                   System.out.println("Enter Name / Enter 'quit'  to exit");
          System.out.println("Client : ");
                  
                  InputStreamReader isr=new InputStreamReader(System.in);
         BufferedReader br=new BufferedReader(isr);  
                 
                      
                  instr=br.readLine();
                  while(!instr.trim().equals("quit"))
                  { 
                      Socket s=new Socket(address,13);             
                      OutputStream os= s.getOutputStream();
             OutputStreamWriter osw=new OutputStreamWriter(os);
                      PrintWriter pw=new PrintWriter(osw);
              
             pw.println(instr);
                      pw.flush();
                   
                      InputStream inStream=s.getInputStream();
                      InputStreamReader ipr=new InputStreamReader(inStream);
                      BufferedReader brs=new BufferedReader(ipr);
                              
                         str=brs.readLine();

                      System.out.println("Reply form Server is :  "+str);
                      System.out.println("\n\n==========================");    
                       System.out.println("Enter Name / Enter 'quit'  to exit");
             System.out.println("Client : ");
                      instr=br.readLine();    
                  }

          br.close();
          System.exit(0);                                   

       }
 }

    catch(Exception e)
        {
            System.out.println("Exception caught is::"+e);    
        }    

     }

}    


OUTPUT :

iptabel.txt
----------

www.yahoo.com 127.0.0.1 13
www.hotmail.com 127.12.1.1 13
www.glsict.org 127.0.2.12 13
www.rediffmail.com 127.1.32.1 13



// Client
C:\jdk1.1.3\bin>java eclient

==========================
Enter Name / Enter 'quit'  to exit
Client :
www.glsict.org
Reply form Server is :  URL=www.glsict.org IP Address= 127.0.2.12


==========================
Enter Name / Enter 'quit'  to exit
Client :
quit

C:\jdk1.1.3\bin>


// Server 
C:\jdk1.1.3\bin>java eserver
Client Requested : www.glsict.org
URL          :: www.glsict.org
IP Address :: 127.0.2.12

Client has Disconnected.....

C:\jdk1.1.3\bin>