Use Apache OPENJPA to develop EJB 3.0 applications, part 7th

Developing OPENJPA applications using Eclipse Dali

About the Eclipse Dali JPA Tools

Dali JPA Tools is a plug-in that is launched by eclipse.org to support JPA project development, with the primary goal of providing visual tool support for users to develop and edit the mapping relationships of JPA entities in EJB 3.0. Dali is part of the Eclipse WTP (Web Tools Platform) toolset, a toolset provided by eclipse.org to support Web applications and Java EE application development.

The latest version of the current Dali is 1.0, which is part of WTP 2.0 and does not offer stand-alone downloads. Dali 1.0 supports Eclipse version 3.3 and WTP 2.0. All of the descriptions in this article are for the Dali 1.0 version. Dali also has a 0.5 version that can support Eclipse 3.2 and WTP 1.5, and Dali 0.5 and 1.0 are not significantly different in functionality and usage, so they can be an option for older versions of Eclipse and WTP users.

The Dali toolset provides a dedicated JPA perspective for user development of JPA applications, consisting primarily of Package Explorer, Data Source Explorer, JPA Structure, and JPA Details views, Package Ex Plorer is used to manage all JPA projects, the data Source Explorer view is used to manage database joins, and the JPA Structure and JPA Details views are the most important part of the JPA perspective for managing mappings between Java objects and databases Shooting relationships, inheritance between entities, association relationships, and the primary key generation strategies of entities.

Typical processes for using Dali development

Dali currently supports the development process from database generation entities, where the developer first creates the database structure, and then uses the wizards provided by the Dali tool to generate entities from the database table structure, and to adjust entity primary key generation policies, inheritance between entities, associations, and so on using perspectives and views. This is a good way to get used to the development team that first completes the database design in the system development process, they can build the entity directly based on the designed database structure, then make the related adjustment. This article will demonstrate this development process.

The Dali also supports the development process of generating database tables from entities by using the Dali tool to create entities, then using perspectives and views to adjust entity primary key generation policies, inheritance between entities, association relationships, and so on, and then building a database table structure based on those entities and relationships. However, this feature is not yet perfect and needs to wait for Dali to provide more features in the new version.

Tools download, install

Download the Dali tool to access eclipse.org for download links. Readers are asked to choose the appropriate Dali version of their version of Eclipse and their environment, Dali 1.0 requires the support of Eclipse 3.3 and WTP 2.0, and Dali 0.5 versions can use Eclipse 3.2 and WTP 1.5 versions 。

To run the Dali tool, you will also need to download and install more than JDK version 5.0 to access the Sun Web site for the latest version of the JDK.