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Section 3. Example 1: Creating the entity bean

CMP Fundamentals: An overview by example

The first example introduces you to the fundamental concepts of CMP including the

following:

defining CMP fields in the deployment descriptor

how to reference an enterprise bean from another bean,

how to reference an enterprise bean from a client.

In this example, I will create three things:

An entity bean (

UserBean

) that uses container managed persistence.

A session bean that accesses the entity bean (

UserManagementBean

).

A client that access the entity bean (Section2Client).

UserBean

(entity bean)

The

UserBean

represents a user in the system. The

UserBean

, like all enterprise

beans, needs three Java source files as follows: a home, an interface, and an

implementation. Thus, you need to define the following code:

Local Interface (

LocalUser

)

Local Home Interface (

LocalUserHome

)

Entity Bean Class (

UserBean

)

The source code for this example can be found at

cmpCmr/section2/src

. To compile

this example go to

cmpCmr/section2

and type

ant

at the command prompt. A sample

.ear

will be created in the

cmpCmr/section2/final

directory. If you are using the

reference implementation, you can deploy this

.ear

with the

deploytool

program.

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Introducing EJB CMP/CMR, Part 1 of 2