A problem with annotation @EJB

Question

Hi,
My application uses servlet+JSP+EJB+JBOSS. I want to use a pure java object that is a singleton and within this singleton call an EJB.
I have a servlet that call a singleton:
My servlet
public class FindAdministratorForumServlet extends HttpServlet {
     private static final long serialVersionUID = 1L;
     // ======================================
     // = Entry point method =
     // ======================================
     @Override
     protected void service(final HttpServletRequest request,
               final HttpServletResponse response) throws ServletException,
               IOException {
          final int rows=3;
          int page = Integer.parseInt(request.getParameter("page"));
          List<Topic> discussionList = ListHandlerService.getForumTopics(page); My singleton :
package service;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
import javax.ejb.EJB;
import sessionbean.TopicService;
import entitybean.Topic;
public class ListHandlerService {
     private final static int rows=3;
    /** L'instance statique */
    private static ListHandlerService instance;
    /** objet pour la synchronisation.
     * j'ajoute deux "soulignés" (__) au nom de l'attribut car il n'a
     * qu'un intérêt purement technique.
    private static Object objetSynchrone__;
    private static List<Topic> listTopic;
     @EJB
     private static TopicService discussionService;
    /** Récupère l'instance unique de la class Singleton.
    * Remarque : le constructeur est rendu inaccessible
    public static ListHandlerService getInstance() {
        if (null == instance) { // Premier appel
            synchronized(objetSynchrone__) {
                if (null == instance) {
                    instance = new ListHandlerService();
        return instance;
    /** Constructeur redéfini comme étant privé pour interdire
    * son appel et forcer à passer par la méthode
    private ListHandlerService() {
    public static List<Topic> getForumTopics(int page) {
         int i = 0;
          Topic topic;
          LinkedList<Topic> result = new LinkedList<Topic>();
         if (page==1) {
              listTopic = discussionService.getForumTopics();
              ListIterator<Topic> listIterator = listTopic.listIterator();
              while (listIterator.hasNext() && (i< rows)) {
                   topic = listIterator.next();
                   result.add(topic);
                   i++;
         } else {
              ListIterator<Topic> listIterator = listTopic.listIterator();
              while (listIterator.hasNext() && (i< rows*(page-1))) {
                   listIterator.hasNext();
                   i++;
              while (listIterator.hasNext() && (i< rows*page)) {
                   topic = listIterator.next();
                   result.add(topic);
                   i++;
         return result;
    public static int getSize() {
         return listTopic.size();
} In my singleton that is a pure JAVA object, the injection of my EJB with annotation @EJB doesn't seem to work. Indeed when executing, "discussionService" that should be injected and initialized, is null. Isn't it possible to inject an EJB in a pure java object which is a singleton ?
Thank you for your answers.

Answer 1

Is it deployed in the same application?
In they are not in the same application you need to use some other techniques. See the following thread for info:
http://forums.sun.com/thread.jspa?threadID=5332558