Thanks!
This is great information.

I will go ahead and do it this way.

Regards,
Klaas Waslander


> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Sent: maandag 3 mei 2004 15:28
> To: [email protected]
> Subject: Re: Having one Registry instance in J2EE apps
> 
> 
> I would suggest to use a combination of a) and b).
> Hold the single instance of the registry in a singleton class, but
> don't initialize it statically. It's better to provide a 
> static method 
> 'setRegistry' which must be called on system initialization.
> In a web application you can initialize the registry from a servlet 
> (that is loaded on startup) or a context listener and store 
> the registry 
> instance by calling this method. Look at Case Study #1 for an example 
> how to do this.
> Redeployment (Tomcat) ist working without problems in my case.
> 
> Regards
> Achim Huegen
> 
> Klaas Waslander wrote:
> > Hi,
> > 
> > I want to start using Hivemind for our reusable Java 
> services across multiple projects. It abstracts nicely from 
> specific J2EE mechanisms, and forces an abstract 
> java-interface-only spec of each service.
> > 
> > Question is the following: 
> RegistryBuilder.constructDefaultRegistry rebuilds the 
> registry every time. That is not good if POJO's, servlets and 
> JSPs use that to get service instances all the time.
> > 
> > For JSP/servlet environments there is the HiveMindFilter 
> that provides one registry through a request attribute. That 
> is not good enough, because I want to be able to get the same 
> instance from POJO's as well, that have no knowledge of the 
> servlet request.
> > 
> > My idea is the following:
> > - have a "HiveRegistry" class of myself, with a static 
> getService method
> > - this method gets the registry and returns the service from it
> > - the way it gets the registry can be:
> >   a) static singleton in the same class
> >   b) registry instance from JNDI context, with a startup 
> class registering the instance in JNDI
> > 
> > Option (a) works okay with webapps I think, as each webapp 
> would generally get its own classloader, and as such its own 
> instance in the static variable. Hot (re-)deployment could 
> work then, have to test. Ideas?
> > 
> > Option (b) would mean a servlet context listener that would 
> create the registry, put it in the webapp JNDI context, and 
> the HiveRegistry class simply returning it from JNDI.
> > 
> > I am aiming for option a (naturally), however am not sure 
> if it's the best one. Also am wondering if this can be 
> incorporated in the Hivemind framework itself, instead of 
> having to deal with this myself.
> > 
> > Looking forward to your input!
> > 
> > Regards,
> > Klaas Waslander
> > 
> > 
> > --
> > Klaas Waslander
> > Systems Architect
> > Tiscali NL
> > website: www.tiscali.nl
> 
> 
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