Seperate business logic from application logic

Question

Hi guys,
I am looking for a good article explaining the princiaples of seperating between Business Logic & Integartion logic.
The articale will be used to exlplain the prinicples SAP PI is based on when it comes to integration between 3rd party systems (Non -SAP) missign the application layer and buisness logic.
If any one has a link to an article as such.
Will be most appriciated.
Regards.
Nimrod Gisis

Answer 1

It seems that the general rule to making a GUI
application is to seperate the "Business Logic" from
the "Presentation Logic". This is absolutely true.
From this, I'm guessing I'll
need to package all my GUI stuff together, and all the
business logic layer stuff together.If you mean the package names and structure then I would had adapted this structure:
1. I will have a package under which I will put the application common classes and interfaces.
com.myapp.common.eventhandler.EventHandler (interface)
com.myapp.common.eventhandler.AbstractEventHandler (default implementation)
com.myapp.common.form.Form (interface)
com.myapp.common.form.AbstractForm (default implementation)2. Create for each subject area its own package:
com.myapp.product.AddNewProductForm
com.myapp.product.AddNewProdcutEventHandler
com.myapp.sales.PriceListEeventHandler
com.myapp.sales.PriceListEeventHandler
The GUI will then talk to the Biz lay through an
interface right?As I illustrated through my previous example, you should have common interfaces and you might need to create Abstract classes that encapsulates the common implementation for these interfaces, then for each GUI Form or Web Page you will create its specific implementation class which inherits from the abstract class.
Finally if you were asking about the deployment packaging:
1. Create for each EJB its own jar file then bundle these Jar files under one module jar file, which represents the EJB module.
2.Package the web application (JSP, Servlets, HTML, Images, CSS, and Java script) in one Web module WAR file.
3. Package your client application module in its own jar file.
4. Assemble the EJB module Jar, Web module War, and Client module Jar in one J2EE package which will be an EAR file so that your whole package will be assembled in one EAR file at the end.
Try the "Application Assembly Tool" which comes with WebSphere. It will organize your application and facilitate this kind of integration.
- Sherif.