used to reduce coupling between Web and EJB tiers.
All the request from Web tier to EJB tier goes through Buisness Delegate, So that, if something changes in EJB Tier will not affect Web Tier and vice versa.
Normally, For an application J2EE design pattern flow will be something like,
---> Service Locator | Client --> Front Controller --> Business Delegate --| | | ----> Session Facade
In the above figure, If you see all the interaction between VIEW(JSP) to Business Tier(EJB tier) goes through Business Delegate.
used to reduce coupling between Web and EJB tiers.
All the request from Web tier to EJB tier goes through Buisness Delegate, So that, if something changes in EJB Tier will not affect Web Tier and vice versa.
Normally, For an application J2EE design pattern flow will be something like,
In the above figure, If you see all the interaction between VIEW(JSP) to Business Tier(EJB tier) goes through Business Delegate.
yes,J2EE clients(JSPs) interact with service components, such as Enterprise JavaBeans (EJB) which provide business services ,through Business Delegate .Business Delegate uses service locator to locate these business services .
-------------------- <br />SCJP 1.4<br />SCWCD 1.4<br />SCBCD 5(in progress)<br /> <br />"Do, what you think that you cannot do"
Other than perhaps for retrieving a collection for populating a select dropdown box, a JSP should not be making any calls to the back end. Calls to the back end are typically business-related and belong in the controller classes.
A good workman is known by his tools.
KRK Gowda
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Joined: Nov 02, 2004
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Thnx Marc for your reply
navat venu
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Other than perhaps for retrieving a collection for populating a select dropdown box, a JSP should not be making any calls to the back end. Calls to the back end are typically business-related and belong in the controller classes
Hi Marc, Normally we do retrieve a collection for populating a select dropdown box in the "load-on-startup" servlet itself and do data caching in memory(Application variables),so that call to backend is done only once at the application startup and further, jsps which have dropdown box will retrieve the collection from memory rather than making calls to backend every time.
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