Hi Angelo, I was just thinking how can you organize your application in case you would use the EJBs:
You will most probably use the Session Facade design pattern ( http://java.sun.com/blueprints/corej2eepatterns/Patterns/SessionFacade.html) to provide the backend for your web apps that will be shared part across all of them. For that you need to create one or many session beans. It's natural that you will not be very happy about complexity of EJBs (in EJB 2) and/or about immature dependency injection (in EJB 3) therefore you would most probably use them only as facade and call some other dependency injection solution behind them. Most probable candidate is Spring, however I'm pretty sure you can adjust T5 IOC to be usefull on the backend side as well. Since EJB structure is very similar to the typical DI requirements (required interfaces) you can easily create a service provider of some kind that will automagically lookup the EJBs in the JNDI and inject them into your pages/services wherever they are needed. I would also suggest you to keep the user dependent state on the web tier and use when possible stateless components on the backend. All in all it seems that resulting structure might become complicated very fast :( and also there is a big question wherever T5 IOC is really suitable for the backend/EJB like operation (for example perthread lifecycle only works when servlet filter is there). Also you need to take into account Java5/JEE5 support is not very mature and you would have only limited choise of containers in this case. Renat On 04/02/2008, Angelo Chen <[EMAIL PROTECTED]> wrote: > > > Hi Renat, > > I think your recommendation of j2ee and ear deployment is a better option, > i > think again, there is really no need to make the multiple module looks > like > one, we can have multiple web applications, now this T5 IOC inside EJB > part > without EJB is interesting, what's the advantage of this approach compared > to using ejb? another thing is, T5 does not have direct support of ejb3 > annotation. > > Thanks, > Angelo > > > Renat Zubairov wrote: > > > > Hi Angelo, > > > > Basically if you have a number of web application, Tap or not Tap :) > there > > are number of problems you need to solve if you want them to look as one > > application for the user: > > > > 1. Authentication - in case you would use propreitary authentication > > schemes > > that are based on the HTTP sessions you might have some problems because > > session would be different for different web applications therefore you > > might need to integrate with the container managed authentication. > > > > 2. Persistence - as you mentioned in your first email "all modules > should > > share the same persistence store" since two different web application > > can't > > have common classes loaded at the same time (due to the fact that in > > Servlet > > container all WebApps are having it's own private classloader) you might > > use > > the same persistence module (a JAR file in the WEB-INF/lib) but in this > > case > > each web application would work with it's own Session (hibernate > or JDBC > > session). > > > > 3. Linking - since each web application will be deployed under different > > context (http://your-domain.com/context1 and http://your-domain/context2 > ) > > you would need to consider how many links would you need between these > two > > and how to manage them efficiently (imagine context name changed?). > > > > Basically my recommendation would be - do it inside single web app :) > you > > will really have less problems! > > > > In case it's not possible I would suggest to leverage all J2EE parts of > > the > > container, such as JAAS and container managed authentication for > > simplifying > > multi-app authentication, JNDI and connection pooling for providing > single > > DB connection pool for multiple applications. > > In case you are planning to deploy to a J2EE container you can benefit > > from > > J2EE deployment if you would put common parts of your application inside > > EJB > > JAR and all your WAR's inside one single EAR, in this case you can > benefit > > from the hierarchical classloading. In the end you can off course use T5 > > IOC > > instead of spring inside your EJB part without really doing any EJBs at > > all. > > IMHO it should be possible to automatically deploy all T5 services > inside > > the JNDI and then look them up in the Web Applications. > > > > Renat > > > > > > On 04/02/2008, Angelo Chen <[EMAIL PROTECTED]> wrote: > >> > >> > >> Hi Renat, > >> > >> EJB is not a must, any suggestions for this kind of app as long as > front > >> end > >> is Tapestry 5. > >> > >> > >> Renat Zubairov wrote: > >> > > >> > Hello Angelo, > >> > > >> > Main question is do you want to use EJB in your app or not, because > >> > usually > >> > there is no proper way to share state between multiple WAR's deployed > >> > inside > >> > the application container. > >> > > >> > Renat > >> > > >> > > >> > > >> > >> -- > >> View this message in context: > >> > http://www.nabble.com/T5%3A-best-practice-for-a-multiple-module-app-tp15260841p15263775.html > >> Sent from the Tapestry - User mailing list archive at Nabble.com. > >> > >> > >> --------------------------------------------------------------------- > >> To unsubscribe, e-mail: [EMAIL PROTECTED] > >> For additional commands, e-mail: [EMAIL PROTECTED] > >> > >> > > > > > > -- > > Best regards, > > Renat Zubairov > > > > > > -- > View this message in context: > http://www.nabble.com/T5%3A-best-practice-for-a-multiple-module-app-tp15260841p15268374.html > Sent from the Tapestry - User mailing list archive at Nabble.com. > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > -- Best regards, Renat Zubairov
