• Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

N-tier applications and Listeners

 
Amila Jayatillaka
Greenhorn
Posts: 28
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi,
I need to know somethings about N-tier web applications.
Actually what I need is to know is how context listeners, session listeners work with them(and others too). Like in a N-tier application does it share same context attributes or how sessions work with it etc...
Reason I’m asking this is I got to know that in SCWCD 5 they are asking something similar things like this.
Thanks in advance.
 
Devaka Cooray
ExamLab Creator
Marshal
Pie
Posts: 4600
306
Chrome Eclipse IDE Google App Engine IntelliJ IDE jQuery Postgres Database Tomcat Server
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hello Amila, are you talking about about n-tier applications or distributed applications? You question makes good sense if it is about distributed applications.
 
Amila Jayatillaka
Greenhorn
Posts: 28
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Devaka Cooray wrote:Hello Amila, are you talking about about n-tier applications or distributed applications? You question makes good sense if it is about distributed applications.


Yes i'm talking about distributed applications....
Actually I thought that N-Tier is about distributed applications
 
Devaka Cooray
ExamLab Creator
Marshal
Pie
Posts: 4600
306
Chrome Eclipse IDE Google App Engine IntelliJ IDE jQuery Postgres Database Tomcat Server
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Well Amila, when your application is deployed on a distributed environment, the session information will transfer remotely to other JVMs in the same environment. In this case, session information should have to be serialized and deserialized in order to pass it as a remote object. Hence you should care about HttpSessionActivationListener an must implement it's sessionDidActive and sessionWillPassivate methods appropriately if it is needed. It is required to do so, if the session stores some connections pooling data / or resources which must be committed and/or closed before serializing them. For the SCWCD exam you are NOT expected to have a deep knowledge about distributed environments. Instead of that, basic understanding about HttpSessionActivationListener is sufficient for the exam. And keep in mind that multi-tier (n-tier) architecture is completely differ than distributed environments.

Devaka.
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic