Difference between @In and Contexts.getConversationContext().get()

31. Jul 2008, 14:20 CET | Link Bogdan Minciu

Hello guys,

I have to use this proxy class in order to avoid concurrent calls exception (http://java.sun.com/blueprints/guidelines/designing_enterprise_applications/ejb_tier/qanda/#prevent):

public class CommentDAOImpl {

    private LocalCommentDAO commentDAO;

    public CommentDAOImpl() {
        this.commentDAO = (LocalCommentDAO) Contexts.getConversationContext().get(CommentDAO.class);
        System.out.println("context= " + Contexts.getConversationContext());
        System.out.println("setted commentDAO= " + commentDAO);
    }
...
}

CommentDAO looks like this:

@Stateful
@Name("commentDAO")
@AutoCreate
public class CommentDAO implements LocalCommentDAO {
...
}

But when I call the constructor of CommentDAOImpl, the commentDAO component is reported as null, even if the class is marked with @AutoCreate:

14:55:18,015 INFO  [STDOUT] context= ConversationContext(3)
14:55:18,015 INFO  [STDOUT] setted commentDAO= null

If I use the @In annotation to inject the commentDAO component in some other stateful components, it works ok and the commentDAO component is created.

So, what is the difference between the @In private LocalCommentDAO; annotation and the Contexts.getConversationContext().get(CommentDAO.class) calls? How can I create a component when it is injected through Contexts.getConversationContext().get(CommentDAO.class)?

Thank you in advance,

Bogdan.