DefaultRevisionEntity

DefaultRevisionEntity is a core class provided by Hibernate Envers, a module of the Hibernate ORM framework that implements auditing and versioning of entity data. It represents a minimal revision entity that tracks changes made to persistent objects over time. The class contains three primary fields: revisionNumber, revisionTimestamp, and a generated identifier. The revisionNumber is an auto‑incremented value that uniquely identifies each revision. The revisionTimestamp holds the epoch time in milliseconds when the revision was created. The identifier field is a primary key coordinating with Hibernate's automatic identifier strategy.

When an entity is annotated with @Audited, Envers records a row in a separate revision table. The DefaultRevisionEntity supplies the foreign key reference for those rows. By default, the revision table is named revinfo, but this can be customized by providing a custom revision entity class that extends DefaultRevisionEntity or by changing the revision entity settings in the Envers configuration. The default implementation is lightweight and suitable for most applications that do not require additional auditing metadata, such as the user who performed the change or the application module responsible.

Developers may replace DefaultRevisionEntity with a custom subclass to add domain‑specific information. For instance, a subclass might include a username field, an IP address, or a custom action descriptor. To use a custom entity, the application configuration must reference the new class via the @RevisionEntity annotation on the custom type. The custom class should be annotated as @Entity and must provide an @Id field compatible with Envers’ expectations. This approach allows extended audit data while preserving the existing default fields.

In summary, DefaultRevisionEntity is a lightweight audit base class that supplies essential revision metadata for Hibernate Envers. It is automatically managed by the framework and is suitable for straightforward auditing scenarios. For applications needing richer audit trails, developers can extend or replace it with custom entities that store additional context.