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XDoclet and EJB technology: ejb.persistence tag

There is no standard

OR

mapping defined by the EJB specification. But most

application servers that implement EJB CMP CMR use a similar strategy, that is,

mapping Entities to classes and fields to columns. The DeptBean EJB component is

going to be mapped to a table called

TBL_USER

.

In older versions of XDoclet, every vendor implementation had their own support for

EJB CMP CMR, yet they all seemed to pick different tags names for doing the same

thing. The newer version of XDoclet defined a tag called

ejb.persistence

to specify

the table name that the entity maps to.

I noticed the Resin XDoclet templates did not support the new

ejb.persistence

tag

yet. I added the support but the new template was not committed into the project yet. It

was actually really easy to modify the template to add the support for the new tag.

Here is the code to map the database table to the entity using the vendor specific

Resin mapping, and the vendor neutral way. Currently not all vendor products are

supported by the new tags. The vendor specific mapping tag is not needed if the

templates for the vendor were updated to support ejb.persistence.

/**...

* @resin ejb.entity bean

sql table="DEPT"

* @ejb.persistence

table name="TBL_USER"

*

...

*/

public abstract class DeptBean implements EntityBean {

The above tags generates the following in the vendor specific mapping files. Resin is

shown as an example.

DeptBean

DEPT

...

Enhance J2EE component reuse with XDoclets

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