AD & LDAP

Could somebody please provide some code sample how to list all users within the domain, including the guuid of each user? Also where is the list of the attributes the AD provides located? URL will be really appreciated.

/**
 * searchforguid.java
 * 5 July 2001
 * Sample JNDI application to perform a search against the Active Directory
 * and also return the objectGUID in both binary and string formats
 * 
 */
 
import java.util.Hashtable;
import javax.naming.ldap.*;
import javax.naming.directory.*;
import javax.naming.*;
 
 
public class searchforguid	{
	public static void main (String[] args)	{
	
		Hashtable env = new Hashtable();
		//Can use either DN, NTLM or UPN style credentials
		String adminName = "b0fh@burunduki";
		String adminPassword = "123456";
		String ldapURL = "ldap://10.0.1.2:389";
		
		env.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.ldap.LdapCtxFactory");
 
		//set security credentials, note using simple cleartext authentication
		env.put(Context.SECURITY_AUTHENTICATION,"simple");
		env.put(Context.SECURITY_PRINCIPAL,adminName);
		env.put(Context.SECURITY_CREDENTIALS,adminPassword);
 
		//specify attributes to be returned in binary format
		env.put("java.naming.ldap.attributes.binary","objectGUID");
 
		//connect to my domain controller
		env.put(Context.PROVIDER_URL,ldapURL);
		try {
 
			//Create the initial directory context
			LdapContext ctx = new InitialLdapContext(env,null);
 
			//Create the search controls 		
			SearchControls searchCtls = new SearchControls();
		
			//Specify the attributes to return
			String returnedAtts[]={"sn","givenName","mail","objectGUID"};
			searchCtls.setReturningAttributes(returnedAtts);
		
			//Specify the search scope
			searchCtls.setSearchScope(SearchControls.SUBTREE_SCOPE);
 
			//specify the LDAP search filter
			//String searchFilter = "(&(objectClass=user)(cn=Albert Einstein))";
			String searchFilter = "(&(objectclass=user)(objectcategory=person));";
 
			//Specify the Base for the search
			String searchBase = "DC=burunduki"; 
 
			//initialize counter to total the results
			int totalResults = 0;
 
 
			//Search for objects using the filter
			NamingEnumeration answer = ctx.search(searchBase, searchFilter, searchCtls);
 
			//Loop through the search results
			while (answer.hasMoreElements()) {
				SearchResult sr = (SearchResult)answer.next();
 
				totalResults++;
 
				System.out.println(">>>" + sr.getName());
 
				// Print out some of the attributes, catch the exception if the attributes have no values
				Attributes attrs = sr.getAttributes();
				if (attrs != null) {
					try {
						System.out.println("   name: " + attrs.get("givenName").get() + " " + attrs.get("sn").get());
						System.out.println("   mail: " + attrs.get("mail").get());
						byte[] GUID = (byte[])attrs.get("objectGUID").get();
						String strGUID = "";
						String byteGUID = "";
						//Convert the GUID into string using the byte format
						for (int c=0;c<GUID.length;c++) {
							byteGUID = byteGUID + "\\" + AddLeadingZero((int)GUID[c] & 0xFF);
						}
						//convert the GUID into string format
						strGUID = "{";
						strGUID = strGUID + AddLeadingZero((int)GUID[3] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[2] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[1] & 0xFF); 
						strGUID = strGUID + AddLeadingZero((int)GUID[0] & 0xFF);
						strGUID = strGUID + "-";
						strGUID = strGUID + AddLeadingZero((int)GUID[5] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[4] & 0xFF);
						strGUID = strGUID + "-";
						strGUID = strGUID + AddLeadingZero((int)GUID[7] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[6] & 0xFF);
						strGUID = strGUID + "-";
						strGUID = strGUID + AddLeadingZero((int)GUID[8] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[9] & 0xFF);
						strGUID = strGUID + "-";
						strGUID = strGUID + AddLeadingZero((int)GUID[10] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[11] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[12] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[13] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[14] & 0xFF);
						strGUID = strGUID + AddLeadingZero((int)GUID[15] & 0xFF);
						strGUID = strGUID + "}";
						System.out.println("GUID (String format): " + strGUID);
						System.out.println("GUID (Byte format): " + byteGUID);
 
					}
					catch (NullPointerException e)	{
						System.err.println("Problem listing attributes: " + e);
					}
				
				}
 
			}
 
	 		System.out.println("Total results: " + totalResults);
			ctx.close();
 
		} 
		catch (NamingException e) {
			System.err.println("Problem searching directory: " + e);
			e.printStackTrace(System.out);
		}
	}
 
	static String AddLeadingZero(int k) {
		return ((k & 0xF) > 0)?"0" + Integer.toHexString(k):Integer.toHexString(k);
	}
 
}

this returns 0 as search results. It alows user b0fh to login (he is in the administrators group), but not search, it seems :(