aspose file tools*
The moose likes OO, Patterns, UML and Refactoring and the fly likes MDB + Entity Bean  / MDB + SB + EB Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Engineering » OO, Patterns, UML and Refactoring
Bookmark "MDB + Entity Bean  / MDB + SB + EB" Watch "MDB + Entity Bean  / MDB + SB + EB" New topic
Author

MDB + Entity Bean / MDB + SB + EB

kri shan
Ranch Hand

Joined: Apr 08, 2004
Posts: 1373
JMS client/JMS destineation(Queue / Topic) sends messages to the MDB instances. Then MDB sends the message to the Entity Bean. Can i add
session bean as a asynchronous wrapper between MDB and Entity Bean.
Hong Anderson
Ranch Hand

Joined: Jul 05, 2005
Posts: 1936
I'm not sure what you want. MDB is a special kind of Session Bean. Why do you want an another session bean?


SCJA 1.0, SCJP 1.4, SCWCD 1.4, SCBCD 1.3, SCJP 5.0, SCEA 5, SCBCD 5; OCUP - Fundamental, Intermediate and Advanced; IBM Certified Solution Designer - OOAD, vUML 2; SpringSource Certified Spring Professional
Jimmy Clark
Ranch Hand

Joined: Apr 16, 2008
Posts: 2187
What is the message? Or, what is in the message? What is the purpose of the message?
kri shan
Ranch Hand

Joined: Apr 08, 2004
Posts: 1373
MDS is stateless. Session Bean may be statefull.
Message is Queue. The purpose of the message is integration between different systems.
Jimmy Clark
Ranch Hand

Joined: Apr 16, 2008
Posts: 2187
Then MDB sends the message to the Entity Bean.


Are these beans in the same EJB container or are they in different containers? Please explain.

The purpose of the message is integration between different systems.


Are you saying that the MDB and the Entity Bean are not in the same system?
kri shan
Ranch Hand

Joined: Apr 08, 2004
Posts: 1373
MDB and Entity Beans are in the different containers.
Jimmy Clark
Ranch Hand

Joined: Apr 16, 2008
Posts: 2187
Which application servers are involved? How many nodes are there?
kri shan
Ranch Hand

Joined: Apr 08, 2004
Posts: 1373
Which application servers are involved? JBoss application server

How many nodes are there? two nodes
Jimmy Clark
Ranch Hand

Joined: Apr 16, 2008
Posts: 2187
Yes, you can add a Session EJB on the node hosting the Entity EJB. The Message EJB would then communication with the Session EJB instead of attempting to directly communicate with the Entity EJB.
kri shan
Ranch Hand

Joined: Apr 08, 2004
Posts: 1373
Hi James, If MDB and Entity Beans are in the same container, can i need Session Bean for wrapper ?
Jimmy Clark
Ranch Hand

Joined: Apr 16, 2008
Posts: 2187
Message-Driven Beans are for handling messages from message queues.

Session Beans are for executing business logic.

Entity Beans
are a temporary object-oriented representation of data.

The code in a Message-Driven bean should not contain business logic. You can certainly code business logic in it, but it would bad design in my opinion. So, if there is any business logic that is associated with the data (Entity Bean) then it should be coded in a Session EJB.

The Entity Bean code should not contain business logic either.

Whether they are in the same container or not is not really relevant. Each bean has a purpose.
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: MDB + Entity Bean / MDB + SB + EB