Generating JDO Persistent Objects

PowerDesigner supports the design of Java classes, database schema and Object/Relational mapping (O/R mapping). Using these metadata, PowerDesigner can also generate persistent objects using Java Data Objects (JDO).

Java Data Objects (JDO) is a standard transparent persistence management API for Java programs that is developed as a Java Specification Request by the Java Community Process. Application programmers can use JDO to directly store their Java domain model object instances into persistent stores such as a relational database, object database or files.

The recommended integration between PowerDesigner and a JDO product is:

Define Java classes, database schema and O/R mapping in PowerDesigner.
Generate Java classes, database and JDO persistence descriptor with O/R mapping from PowerDesigner.
Compile and run the JDO enhancer from PowerDesigner, Ant, JBuilder or Eclipse.

This chapter explains how to use PowerDesigner to define Java classes and O/R mapping, generate JDO persistence descriptor and O/R mapping extension and use an IDE to compile and enhance the Java classes.

To follow this chapter, you will need:

An implementation of JDO, for example, Xcalia LiDO
JDK 1.3 or higher
Apache Ant 1.5 or higher
A Java IDE (optional)

JDO Persistence Management
JDO provides transparent persistence management. It means that a Java developer does not need to write any code for managing the persistence of business objects.
Creating JDO Persistent Objects
The following sections describe how to create JDO Persistent Objects with PowerDesigner.
Generating Java Code and JDO Persistence Descriptor
To run the JDO enhancer, an Ant build.xml file is used.
Compiling Java Code and Running the JDO Enhancer
Before you can use the persistent JDO Java classes, you need to compile them and run the JDO enhancer.