The Customer EJB is a simple CMP entity bean that models the concept of a cruise customer or passenger, but its design and use are applicable across many commercial domains. This section introduces the Customer bean’s development, packaging, and deployment. We greatly expand the bean’s features as we progress through the chapter.
Although CMP is database-independent, the examples throughout this
book assume that you are using a relational database. This means that we
will need a
table from which to get our
customer data. The relational database table definition in SQL is as
CREATE TABLE CUSTOMER ( ID INT PRIMARY KEY NOT NULL, LAST_NAME CHAR(20), FIRST_NAME CHAR(20) )
CustomerBean class is an abstract class that the
container uses for generating a concrete implementation, the
persistence entity class. The mechanism used by the container for
generating a persistence entity class varies, but most vendors
generate a subclass of the abstract class provided by the bean
developer (see Figure 6-4).
Figure 6-4. The container tool typically extends the bean class
The bean class must declare accessor (set and get) methods for each persistence field and relationship field defined in the deployment descriptor. The container needs both the abstract accessor methods (defined in the entity bean class) and the XML elements of the ...