Abstract Base Classes

Abstract base classes contain reusable logic for PeopleCode classes; you do not instantiate them directly. Instead, you instantiate classes that are subclasses of the abstract base class. Abstract base classes use placeholder methods for specialized logic, and its subclasses override those methods to provide the specialized logic.

An example of a candidate for an abstract base class is a class that is used for administering a data entity, such as an invoice. Such a class has a Save method. A Save method can use normal methods to call generic validation routines, talk to the database, and handle errors; it can use the placeholder methods for specialized logic, such as mapping a given data class to a particular database table.

PeopleSoft recommends that you program an active validation check into your placeholder method that causes a runtime error, such as throwing an UnimplementedMethodException, if an abstract base class placeholder method hasn’t been overridden.