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Business Delegate??

 
Andy Smith
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Wats the Proble Statemnet behind Business Delegate??
Can anyone plz explain with an examplw
 
Michael Ernest
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The exam asks in which tier a Business Delegate belongs. Your choices would be the Presentation, Business, or Integration tier.
 
Ko Ko Naing
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Originally posted by Andy Smith:
Wats the Proble Statemnet behind Business Delegate??
Can anyone plz explain with an examplw

Here is what I extracted from SCWCD Study Kit for u... Hope it might help u..
Problem
Business services implemented by the business-tier components are accessed directly by the presentation-tier components through the exposed API of the services. However, the interfaces of such services keep changing as the requirements evolve. This affects all the components on the presentation tier. Furthermore, all the client-side components have to be aware of the location details of the business services�that is, each component has to use the JNDI lookup service to locate the required remote interfaces.
Example
In the case of the J2EE architecture, the server components that expose the business service API are the session beans, the API is the remote interface implemented by the session beans, and the client components that use these services are servlets and the JavaBeans used in JSP pages. Figure 17.6 shows this relationship.
Let�s look at a real-world example. A company is building a web-based application with JSP pages and servlets that need to access a set of business services. The management has decided not to develop the business services in-house, since they are readily available as off-the-shelf software from various vendors. In addition, the budget for the project
is currently tight, so management has decided that they will purchase one of the more economical off-the-shelf solutions initially, and then when the money becomes available in a year, they will replace it with a more elaborate and expensive software solution.
 
Ko Ko Naing
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Originally posted by Michael Ernest:
The exam asks in which tier a Business Delegate belongs. Your choices would be the Presentation, Business, or Integration tier.

Business Delegate is under business tier, even though it resides in the presentation tier as an object and directly contact with web components in the presentation tier...
 
Andy Smith
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Thanx Naing/ Michael...
So as far as my understanding the Business Delegate is used to hide the Business interfaces from the presentaion layer. If change is made to the business interface it should not effect the presenation layer.
Eg. Suppose the presenation layes is recieving data from the file..till the time the database is not ready. when database gets ready the business interface is change to get the data from the DB rather then File.. withouth changint the Presenation interaction
m I rite in my unserstanding...?
 
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