Multichatserver

import java.net.*;
import java.awt.event.*;
import java.awt.*;
import java.io.*;
import java.util.*;

class  ClientInfo{
String name;
Socket cs;
public ClientInfo(String nm,Socket s)
{
name = nm;
cs = s;
}

}



public class multichatserver {

ServerSocket  ss;
Socket s;
Hashtable list;
PrintStream chatLog;
Vector namevect;


public multichatserver()
{
list = new Hashtable();
namevect = new Vector();
try
{
chatLog = new PrintStream(new FileOutputStream("multichat.log"));
}catch(IOException e)
{
System.out.println("Error opening file");
System.exit(1);
}
  try{
ss = new ServerSocket(2000);
while(true)
{
System.out.println("SERVER READY TO TAKE REQUESTS");
s = ss.accept();
new FileThread(s).start();

}
}catch(IOException ioe)
{
System.out.println("IOException Caught");
}
}


class FileThread extends Thread{

Socket fs;
BufferedReader br;
String name;
public FileThread(Socket s)
{
fs = s;
}
public void run()
{
try
{
InputStream  is = fs.getInputStream();
OutputStream os = fs.getOutputStream();
br = new BufferedReader (new InputStreamReader(is));
while((name = br.readLine())!=null)
{
 if(list.containsKey(name))
 {
  continue;
 }
 else
 {
 ClientInfo cinfo = new ClientInfo(name,fs);
 chatLog.println(name+" Registered from Host:"+fs.getInetAddress().getHostName()+"and IP address:"+fs.getInetAddress().getHostAddress() );
 list.put(name,cinfo);
 Enumeration enumS = list.elements();
 namevect.addElement(name);
 while(enumS.hasMoreElements())
 {
   ClientInfo clinfo =(ClientInfo)enumS.nextElement();
   System.out.println("client name"+clinfo.name);
   new DataOutputStream(clinfo.cs.getOutputStream()).writeInt(1);
   ObjectOutputStream obos = new ObjectOutputStream(clinfo.cs.getOutputStream());
   obos.writeObject(namevect);
   obos.flush();
 }
 new messageThread(name,fs).start();
 System.out.println("Thread Started.");
 break;
 }
  }

   }
  catch(IOException ioe)
  {
  System.out.println("IOException Caught");
  }


}
}

class messageThread extends Thread{
Socket ms;
String name;
public messageThread(String nm,Socket s)
{
ms = s;
name = nm;
}

public void run()
{
InputStream is;
OutputStream os;
BufferedReader br;
String message;
try{
is = ms.getInputStream();
   os = ms.getOutputStream();
   br = new BufferedReader(new InputStreamReader(is));

while((message = br.readLine())!=null)
   {
  System.out.println("message sent from "+ name);
      Enumeration en = list.elements();
  while(en.hasMoreElements())
   {
    ClientInfo clinf = (ClientInfo)en.nextElement();
    if(!clinf.name.equals(name))
    {
     new DataOutputStream(clinf.cs.getOutputStream()).writeInt(0);
   //clinf.ps.println(name+": "+message);
   PrintWriter pw = new PrintWriter(new OutputStreamWriter(clinf.cs.getOutputStream()),true);
   pw.println(name+": "+message);
       }
//clinf.ps.println(name+": "+message);
   }

  }
  System.out.println("out of while loop");

}catch(IOException ioe)
{
list.remove(name);
chatLog.println(name + "Quits.");
return;
}


}

  }




  public static void main(String args[])
  {
 multichatserver mcs = new multichatserver();
  }
}