How to Put Business Logic In the Right Place in java

Put Business Logic In the Right Place

In general, you should not implement business logic in your client program. Instead, put validation and defaulting logic in your entity objects, and put client-callable methods in application modules, view objects, and view rows.

Working with application module methods allows the client program to encapsulate task-level custom code in a place that allows data-intensive operations to be done completely in the middle-tier without burdening the client.

Working with view object methods allows the client program to access the entire row collection for cross-row calculations and operations.
Working with view row methods allows the client program to operate on individual rows of data. There are three types of custom view row methods you may want to create:

• Accessor methods: The oracle.jbo.Row interface (which view rows implement) contains the methods getAttribute() and setAttribute(), but these methods are not typesafe. You can automatically generate custom typesafe accessors when you generate a custom view row class.

• Delegators to entity methods: By design, clients cannot directly access entity objects. If you want to expose an entity method to the client tier, you should create a delegator method in a view row.

• Entity-independent calculations: This is useful if the calculation uses attributes derived from multiple entity objects or from no entity objects.