Enterprise JavaBeans, Third Edition

The Customer EJB

In the following example we will develop a simple CMP 2.0 entity bean—the Customer EJB. The Customer EJB models the concept of a cruise customer or passenger, but its design and use are applicable across many commercial domains.

As the chapter progresses, the Customer EJB will be expanded and its complexity will increase to illustrate concepts discussed in each section. This section serves only to introduce you to the entity bean and some basic concepts regarding its development, packaging, and deployment. To simplify things, we will skim over some concepts that are discussed in detail later in the chapter.

Figure 6-3. J2EE 1.3 SDK deployment tool

The Customer Table

Although CMP 2.0 is database independent, the examples throughout this book assume that you are using a relational database. This means that we will need a CUSTOMER table from which to get our customer data. The relational database table definition in SQL is as follows:

CREATE TABLE CUSTOMER 
(
    ID INT PRIMARY KEY NOT NULL, 
    LAST_NAME CHAR(20), 
    FIRST_NAME CHAR(20)
)

The CustomerBean

The CustomerBean class is an abstract class that will be used by the container tool for generating a concrete implementation, the persistence entity class, which will run in the EJB container. The mechanism used by the container tool for generating a persistence entity class varies, but most vendors generate a subclass of the abstract ...