You can use the UML-to-JPA
transformation to generate Java Persistence
API (JPA) entities and Java code from Unified Modeling Language (UML)
model elements. You should be familiar with the UML-to-Java and UML-to-EJB
3.0 transformations before you run the UML-to-JPA transformation.
About this task
You can use this transformation in both of the following
round-trip-engineering (RTE) scenarios:
- Transform a UML model into code, change the code, and then transform
the changed code into UML (model-code-model)
By default, the IBM® Rational® modeling products support
this scenario.
- Transform existing JPA entities and Java code
into a UML model, change the model, and then transform the changed
model into Java code (code-model-code)
To
use this transformation in a code-model-code scenario, which begins
by running the JPA-to-UML transformation, you must link the existing
JPA entities and Java code elements
to the UML model elements in the model that the JPA-to-UML transformation
generates. This linking adds annotations and comments to the code
so that the UML-to-JPA transformation can propagate the UML changes
to the JPA entities and Java code,
and preserve existing method bodies. You should link the elements
before you modify the recently added model elements and run the UML-to-JPA
transformation. After you link the elements, subsequent transformations
merge as you expect.
Note: To link the code elements to the UML model
elements, on the Main page of the UML-to-JPA transformation configuration,
click Link Java to UML.
For more
information about this scenario and merging changes when you develop Java Persistence API entities and
UML, see the related concept topic below. Although this related topic
describes the workflow for the Java transformations,
the workflow is the same for the UML-to-JPA and JPA-to-UML transformations.