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MyEclipse JPA Development Overview |
Table of Contents
1. Introduction
This document presents an overview of JPA features available in
MyEclipse 6.0.
To
get a better feel for MyEclipse and learning more about it,
please check out our product
Documentation for more
material.
2.
JPA Project Configuration
a) Persistence Providers
MyEclipse provides support for the Toplink Essentials and Hibernate 3.2 JPA providers. Support for OpenJPA is planned.
Figure 2.1. Adding JPA Capabilities
b) Database Configuration
Create a persistence unit and associate your project with a
database and schema for design-time tool support. The project in
the next screenshot is being associated with the database driver
for the local
MyEclipse Derby database.
Figure 2.2. Configure the datasource
The Enable dynamic DB table creation option was introduced in MyEclipse 6.0.1. This is a runtime configuration option that when checked, instructs the application's persistence provider to automatically create any missing database tables required to support the persistent entities of your application. This features makes testing your application against a temporary database much easier and faster, allowing you to deploy your application quickly with minimal database configuration.
You may change a JPA project's database driver association at any time using the Java Persistence properties page. To invoke this page, right click on the project and select Properties from the context menu. From the Properties dialog shown below, expand the MyEclipse node and select Java Persistence.
Figure 2.3. Java Persistence properties page
3. Reverse Engineering Entities and DAOs from Database
a) Entity Generation
Initiate Entity generation from the context menu of a JPA project.
This will launch the JPA Reverse Engineering Wizard.
Figure 3.1. Entity generation from JPA project
Entity generation can also be initiated from the Database Browser view.
Figure 3.2. Entity generation from DB Table
The reverse engineering process is fully customizable. Using the JPA Reverse Engineering Wizard you can choose the artifacts to generate and the database tables from which the artifacts will be based.
Figure 3.3. Customize reverse engineering
A new feature introduced in MyEclipse 6.0.1 is the option to generate DAOs with result pagination support for findBy<property> queries. The generated result pagination API provides DAO clients fine-grained programmatic control to position to a specific row number of a resultset and fetch 'n' entities.
Following are several sample snippets of the code generated by the Reverse Engineering Processor.
Figure 3.4. Sample snippets
4. Advanced Entity Editing Tools
a) MyEclipse Java Persistence Perspective
The MyEclipse Java Persistence Perspective provides an optimal editor and view layout for JPA oriented tasks.
Figure 4.1. MyEclipse Persistence perspective
b) JPA Details View
The JPA Details view makes it easy to edit entity annotations.
Figure 4.2. JPA Details view- Select table
Figure 4.3. JPA Details view - Edit detail
c) JPA Annotation Table and Column Content Assist
Figure 4.4. Table Content Assist
Figure 4.5. JPA annotation column content assist
d) JPA Entity Validation
Errors in your mapping are detected and displayed in the editor
and problems view.
Figure 4.6. JPA validation errors shown in Java editor
The JPA Entity Validator can be enabled or disabled at the project level.
Figure 4.7. JPA Validation preferences
5. Advanced Spring-JPA Integration
a) Spring 2 Support
When adding JPA Capabilities to a project that already has Spring capabilities or vice versa, you can choose advanced Spring-JPA support. This level of support enables JPA tools to work with your project's Spring artifacts. Following is a screenshot of the Spring-JPA project configuration wizard.
Figure 5.1. Adding Spring Capabilities Wizard
Select your primary bean configuration file and customize bean Ids and transaction support.
Figure 5.2. Configure Spring-JPA support
b) Reverse Engineering Entities and Spring DAOs from Database
For projects that are configured to support advanced Spring-JPA
capabilities, in addition to generating Entity classes from a
database schema, Spring compatible DAOs can be generated. During
the reverse-engineering process the Spring application context
file is updated with generated bean entries for each DOA class.
Figure 5.3. Generate Spring DAOs.
Figure 5.4. Generated Spring application context file.
Figure 5.5. Generated Spring DAO extends from Spring's JpaDaoSupport.
6. Feedback
We would like to hear from you! If you liked this overview, have some suggestions or even some corrections for us please let us know. We track all user feedback about our learning material in our Documentation Forum. Please be sure to let us know which piece of MyEclipse material you are commenting on so we can quickly pinpoint any issues that arise.