Dali JPA Tools

Getting Started with Dali

To work with Java Persistence Entities you need couple of prerequisites:

• An installed 1.5 JRE or higher
• A Java EE 5 compliant runtime or compliant Java Persistence API implementation. You can download a JPA implementation from Eclipse (EclipseLink) or from a number of other open source and commercial vendors.

To work with Java Persistence Entities you need to create a JPA Project:

• Make sure your Project's Java Compiler Compliance Level is set to 5.0
• Select File->New Project...JPA->JPA Project
• Follow the instructions on the Wizard. You'll need to identify the jar containing the JPA annotation definitions so your entities will compile. You'll also need to select, or define, a database connection that will be used to access relational schema information.

To create a new persistent Entity:

• Create a new Java Class and add this class to your persistence.xml file
• In the JPA Details view, select to map the class as an Entity.
• Or use the New Entity Wizard.

To make an existing POJO an Entity:

• Open the persistence.xml file using the Persistence XML Editor. Add the class to the Managed Classes list.
• Or simply add the "@Entity" annotation to any existing POJO class definition. The Dali tools will pickup the change and the editing views will activate.

Take a look at the viewlet demos on the Dali Home Page for a walk through of building property access and field access Entities.

Running JPA Applications 'Out of Container'

How you run your JPA application in a compliant runtime in a Java SE environment ('out of container') is vendor specific. We'll add links to how-to's for any runtime we're told about. Post to the Dali newsgroup or mailing list if you have a how-to you'd like included.

• EclipseLink Java SE How-To
• TopLink Essentials Java SE How-To
• JBoss Hibernate How-To

Notes

• In order to compile JPA Entities, it is a requirement that the appropriate jar(s) from a JPA runtime are available on the project classpath. The "Add Java Persistence..." wizard will help you add the required library to your project classpath. You must have previously installed a Java EE 5 or JPA persistence runtime implementation--one is not distributed with Dali. If you are working inside of a WebTools Enterprise Application Project, no classpath configuration is needed as your classpath should already contain the appropriate jars from your Server configuration, assuming the server supports EJB 3.0.
• Currently Dali only supports one Persistence Unit and one Persistence XML file per project. Other configurations can exist in a JPA project, but the validation and defaults processing may not be correct when multiple persistence units are used.