JNDI, Active Directory and Persistent Searches (part 2)

Question

The original post of this title which was located at http://forum.java.sun.com/thread.jspa?threadID=578342&tstart=200 subsequently disappeared into the ether (as with many other posts).
By request I am reposting the sample code which demonstrates receiving notifications of object changes on the Active Directory.
Further information on both the Active Directory and dirsynch and ldap notification mechanisms can be found at http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ad/ad/overview_of_change_tracking_techniques.asp
* ldapnotify.java
* December 2004
* Sample JNDI application that uses AD LDAP Notification Control.
import java.util.Hashtable;
import java.util.Enumeration;
import javax.naming.*;
import javax.naming.ldap.*;
import com.sun.jndi.ldap.ctl.*;
import javax.naming.directory.*;
class NotifyControl implements Control {
     public byte[] getEncodedValue() {
             return new byte[] {};
       public String getID() {
          return "1.2.840.113556.1.4.528";
     public boolean isCritical() {
          return true;
class ldapnotify {
     public static void main(String[] args) {
          Hashtable env = new Hashtable();
          String adminName = "CN=Administrator,CN=Users,DC=antipodes,DC=com";
          String adminPassword = "XXXXXXXX";
          String ldapURL = "ldap://mydc.antipodes.com:389";
          String searchBase = "DC=antipodes,DC=com";
          //For persistent search can only use objectClass=*
          String searchFilter = "(objectClass=*)";
               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);
          //connect to my domain controller
          env.put(Context.PROVIDER_URL,ldapURL);
          try {
               //bind to the domain controller
                  LdapContext ctx = new InitialLdapContext(env,null);
               // Create the search controls           
               SearchControls searchCtls = new SearchControls();
               //Specify the attributes to return
               String returnedAtts[] = null;
               searchCtls.setReturningAttributes(returnedAtts);
               //Specify the search scope
               searchCtls.setSearchScope(SearchControls.SUBTREE_SCOPE);
                     //Specifiy the search time limit, in this case unlimited
               searchCtls.setTimeLimit(0);
               //Request the LDAP Persistent Search control
                     Control[] rqstCtls = new Control[]{new NotifyControl()};
                     ctx.setRequestControls(rqstCtls);
               //Now perform the search
               NamingEnumeration answer = ctx.search(searchBase,searchFilter,searchCtls);
               SearchResult sr;
                     Attributes attrs;
               //Continue waiting for changes....forever
               while(true) {
                    System.out.println("Waiting for changes..., press Ctrl C to exit");
                    sr = (SearchResult)answer.next();
                          System.out.println(">>>" + sr.getName());
                    //Print out the modified attributes
                    //instanceType and objectGUID are always returned
                    attrs = sr.getAttributes();
                    if (attrs != null) {
                         try {
                              for (NamingEnumeration ae = attrs.getAll();ae.hasMore();) {
                                   Attribute attr = (Attribute)ae.next();
                                   System.out.println("Attribute: " + attr.getID());
                                   for (NamingEnumeration e = attr.getAll();e.hasMore();System.out.println("   " + e.next().toString()));
                         catch (NullPointerException e)     {
                              System.err.println("Problem listing attributes: " + e);
          catch (NamingException e) {
                      System.err.println("LDAP Notifications failure. " + e);
}

Answer 1

Hi Steven
How can I detect what change was made ? Is there an attribute that tell us ?
Thanks
MHM