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Chapter 3. Tutorial Using Native Hibernate APIs and Annotation Mappings

Table of Contents

3.1. The Hibernate configuration file
3.2. The annotated entity Java class
3.3. Example code
3.4. Take it further!

This tutorial is located within the download bundle under annotations.

Objectives

The contents are identical to Section 2.1, “The Hibernate configuration file”, with one important difference. The mapping element at the very end naming the annotated entity class using the class attribute.

The entity class in this tutorial is org.hibernate.tutorial.annotations.Event which follows JavaBean conventions. In fact the class itself is identical to the one in Section 2.2, “The entity Java class”, except that annotations are used to provide the metadata, rather than a separate hbm.xml file.


The @javax.persistence.Entity annotation is used to mark a class as an entity. It functions the same as the class mapping element discussed in Section 2.3, “The mapping file”. Additionally the @javax.persistence.Table annotation explicitly specifies the table name. Without this specification, the default table name would be EVENT).


@javax.persistence.Id marks the property which defines the entity's identifier. @javax.persistence.GeneratedValue and @org.hibernate.annotations.GenericGenerator work in tandem to indicate that Hibernate should use Hibernate's increment generation strategy for this entity's identifier values.


As in Section 2.3, “The mapping file”, the date property needs special handling to account for its special naming and its SQL type.

org.hibernate.tutorial.annotations.AnnotationsIllustrationTest is essentially the same as org.hibernate.tutorial.hbm.NativeApiIllustrationTest discussed in Section 2.4, “Example code”.

Practice Exercises

  • Add an association to the Event entity to model a message thread. Use the Developer Guide as a guide.

  • Add a callback to receive notifications when an Event is created, updated or deleted. Try the same with an event listener. Use the Developer Guide as a guide.