Java code to get all users in LDAP Group

//Java code to get all users in LDAP Group

import java.util.Hashtable;
import java.util.Properties;
import javax.naming.Context;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.Attributes;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;

public class GetUsersFrormLDAPGroup {
static String ldapSearchBase = "DC=Company,DC=internal";
private static DirContext ctx = null;
private static DirContext getActiveDirectoryContext() throws Exception {

final Properties properties = new Properties();
properties.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.ldap.LdapCtxFactory");
properties.put(Context.PROVIDER_URL,"ldap://localhost:389");
properties.put(Context.SECURITY_AUTHENTICATION,"simple");
properties.put(Context.SECURITY_PRINCIPAL, "CN=UserName");
properties.put(Context.SECURITY_CREDENTIALS,"Password");
return new InitialDirContext(properties);

}
public void getGroupUsers(String searchBase, String searchFilter, String returnedAttrs[], int maxResults)
{
Hashtable userEntries = null;
String member="";
try{
SearchControls searchCtls = new SearchControls();
searchCtls.setSearchScope(SearchControls.SUBTREE_SCOPE);      
searchCtls.setReturningAttributes(returnedAttrs);
ctx=getActiveDirectoryContext();
try{
System.out.println("Search Base: "+searchBase);
System.out.println("Search Filter: "+searchFilter);
NamingEnumeration users = ctx.search(searchBase, searchFilter, searchCtls);
if(users.hasMoreElements() == false){
System.out.println("Not find any object with this filter " + searchFilter + " and searchBase " + searchBase);
}

int k = 0;
String attValue = "";
userEntries = new Hashtable();
while (users.hasMoreElements()){
if(k >= maxResults)
break;        
SearchResult sr = (SearchResult)users.next();
Attributes attrs = sr.getAttributes();
if (attrs.size() == 0){
System.out.println("Could not find attribute " + returnedAttrs[0] + " for this object.");
}else{

try{          
for (NamingEnumeration ae = attrs.getAll();ae.hasMore();){ 
Attribute attr = (Attribute)ae.next();                
String id = attr.getID();
for (NamingEnumeration e = attr.getAll();e.hasMore();){                
attValue = (String)e.next();
if(id.equalsIgnoreCase("member"))
member = attValue;
System.out.println("member :"+member);
else
{
System.out.println("empty");
}
}
}
}catch(NamingException e){
System.out.println("Problem listing membership:"+e);          
}
}
k++;
}
}catch (NamingException e){
System.out.println("Problem searching directory: "+e);          
}     
ctx.close();
ctx=null;  
}catch (Exception namEx){
System.out.println("Exception while fetching the users from LDAP::"+namEx);      
}    

}
public static void main(String args[]) throws Exception{
GetUsersFrormLDAPGroup gug = new GetUsersFrormLDAPGroup();
String returnedAttrs[] = {"cn","member", "name"};
String searchFilter="CN=GroupName";
gug.getGroupUsers(ldapSearchBase,searchFilter, returnedAttrs, Integer.parseInt("2000"));
}
}