Authentication through LDAP Exchange Server

Attached is the class file which contains checkLogin function. Just pass your form file (LoginForm), which contains user credentials, it will
validate password through LDAP server, VSNL Exchange Server. We need to provide following informations:
1. IP of Host server (LDAP server), and
2. Distinguish name and password of one admin user. here it is pnrapp.geneva@vsnl.co.in and pwd is BIG-small

The method will return true if the password is valid otherwise it will return false.

import java.util.Hashtable;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.*;

import com.vsnl.corp_pos.struts.forms.LoginForm;

public class JNDI
{

    public String INITCTX;
    public String MY_HOST;
    public String MGR_DN;
    public String MGR_PW;
    public String MY_SEARCHBASE;
    public String MY_FILTER;
    public String MGR_DN_SHRT;

    public JNDI()
    {
        INITCTX = "";
        MY_HOST = "";
        MGR_DN = "";
        MGR_PW = "";
        MY_SEARCHBASE = "";
        MY_FILTER = "";
        MGR_DN_SHRT = "";
    }

    public boolean checkLogin(LoginForm loginForm) throws NamingException 
    {
     String s=loginForm.getUser();
     String s1=loginForm.getPassword();     
        INITCTX = "com.sun.jndi.ldap.LdapCtxFactory";
        MY_HOST = "ldap://ldap.vsnl.co.in";
        MGR_DN="cn=pnrapp geneva,ou=hq-wr,ou=vsnl-common id's,dc=vsnl,dc=co,dc=in";
        MGR_PW = "BIG-small";
        MY_SEARCHBASE = "dc=vsnl,dc=co,dc=in";
        MGR_DN_SHRT = "dc=vsnl,dc=co,dc=in";
        MY_FILTER = "sAMACCOUNTNAME=" + s;
        try{         
         Hashtable hashtable = new Hashtable();
         hashtable.put("java.naming.factory.initial", INITCTX);
         hashtable.put("java.naming.provider.url", MY_HOST);
         hashtable.put("java.naming.security.authentication", "simple");
         hashtable.put("java.naming.security.principal", MGR_DN);
         hashtable.put("java.naming.security.credentials", MGR_PW);
         InitialDirContext initialdircontext = new InitialDirContext(hashtable);
         SearchControls searchcontrols = new SearchControls();
         searchcontrols.setSearchScope(2);
         NamingEnumeration namingenumeration = initialdircontext.search(MY_SEARCHBASE, MY_FILTER, searchcontrols);
         SearchResult searchresult = (SearchResult)namingenumeration.next();
         String s2 = searchresult.getName();
         System.out.println("OUT: " + s2);
         MGR_DN = s2 + "," + MGR_DN_SHRT;
         MGR_PW = s1;
         hashtable.put("java.naming.factory.initial", INITCTX);
         hashtable.put("java.naming.provider.url", MY_HOST);
         hashtable.put("java.naming.security.authentication", "simple");
         hashtable.put("java.naming.security.principal", MGR_DN);
         hashtable.put("java.naming.security.credentials", MGR_PW);
         initialdircontext = new InitialDirContext(hashtable);
         initialdircontext = null;        
         return true;
        }catch(NamingException e){
         loginForm.setError(e.toString());
         System.out.println("Exception: "+e);
         return false;
     } catch(Exception e){             
         return false;
  }
    }
    
}