Re: draft Java-api-12

[Steven Sonntag <vtag@novell.com>]

Rob Weltman wrote:

> Steven Sonntag wrote:
>
> > Rob Weltman wrote:
> >
> > > Steve Sonntag wrote:
> > >
> > >>  I have been thinking about the specification forunsolicited
> > >> notifications in the Java api draft version 12. The draft has two
> > >> methods in LDAPConnectionthat are concerned with Unsolicited
> > >> Notifications: one sets a flag indicating whether to keep or
> > >> discardunsolicited notifications:
> > >> setUnsolocitedNotifications(boolean flag)the other gets the value of
> > >> the flag Unsolicited notifications are retrieved by callingthe
> > >> getResponse(0) method from one of theListener classes.  the "0"
> > >> indicates message ID 0. The problem is that a listener has
> > >> association witha connection only when a request is in progressusing
> > >> that listener.  A listener in an application with5 connections open
> > >> could be servicing requestson all five connections or on none of
> > >> them.  UsinggetResponse from the listener class to getUnsolicited
> > >> notifications is problematic.  If no requestsare outstanding on the
> > >> listener, there is no associationwith a connection, so it is not
> > >> possible to checkfor unsolicited notifications. It would seem that
> > >> the only reliable way to check forand get unsolicited notifications
> > >> would be throughthe LDAPConnection class itself and not through the
> > >> listener.classes. Two more LDAPConnection methods - ugh, butperhaps
> > >> necessary? Anyone have any better ideas? -Steve
> > >> ------------------------
> > >> Steve Sonntag
> > >> Novell, Inc., the leading provider of Net services software
> > >
> > >
> > >   It might be better instead to eliminate the current unsolicited
> > > notification methods and instead have methods to add and remove
> > > listeners for usolicited notifications. The implementation can then
> > > discard unsolicited notifications if there are no listeners. For
> > > example (I haven't thought this through completely yet):
> > >
> > > LDAPConnection
> > >
> > > public LDAPResponseListener addUnsolicitedNotificationListener(
> > > LDAPResponseListener listener )
> > >
> > > public void addUnsolicitedNotificationListener( LDAPResponseListener
> > > listener )
> > >
> > > Rob
> > >
> >
> > I like your idea Rob, it fits much better with the rest of the
> > architecture.
> >
> > I have a few questions:
> >
> > Are multiple UnsolicitedNotificationListeners allowed on a given
> > connection.
> > What would the behavior be in such a situation.  The name seems to
> > indicate
> > that multiple are allowed.
> >
> > My take is that only one unsolicited notification listener exists for a
> > given connection.
> > Of course, that listener may be servicing multiple connections (using
> > the first method
> > to create it).  I am not sure of the purpose for the second method.
> > Would the first method be more clearly named
> > "setUnsolicitedNotificationListener",
> > implying there is only one?
> >
> > I assume that getResponse() blocks if no unsolicited notifications are
> > available.
> >
> > getMessageIds would return an array with 0 being one of the message ID
> > values.
> >
> > Could this listener be merged with a regular listener?  There seems no
> > reason why it
> > couldn't.
> >
> > How does one remove an unsolicited notification listener, or was your
> > second
> > method meant to be a delUnsolicitedNotificationListener?
>
>   Yes, except it should be:
>
> public void removeUnsolicitedNotificationListener( LDAPResponseListener listener )
>
>   I was thinking that you could have more than one listener - that's why the method naming (also, of course, to be consistent with the JDK's listener method naming). An implementation could feed each listener with a copy of each incoming unsolicited notification, and each client could pull out notifications independently.
>
> Rob

Sounds good.

Does there need to be a method on LDAPConnection that is something like

    LDAPResponseListener[] getUnsolicitedNotificationListeners()

to discover which listeners are allowed to receive unsolicited notifications on this connection?

-Steve
--
------------------------
Steve Sonntag
Novell, Inc., the leading provider of Net services software