net.sf.mmm.util.entity.api

Interface RevisionedEntity<ID>

Type Parameters:

ID - is the type of the primary key.

All Superinterfaces:

AttributeReadId<ID>, Entity, GenericEntity<ID>, Serializable

All Known Subinterfaces:

MutableRevisionedEntity<ID>, PersistenceEntity<ID>

All Known Implementing Classes:

AbstractRevisionedEntity, EntityTo

public interface RevisionedEntity<ID>
extends GenericEntity<ID>

This is the interface for a GenericEntity that is (potentially) revision-controlled. An instance of this interface represents the revision of a GenericEntity. There are two cases to distinguish:

• latest revision
  A RevisionedEntity pointing to LATEST_REVISION represents the latest state of the entity and can be modified.
• historic revision
  If the object is revision controlled, it has a history of modifications. A RevisionedEntity can represent a historic revision out of this history. It therefore is immutable so operations to modify the RevisionedEntity will typically fail. At least they can NOT be written to the database.

ATTENTION:
Due to the lack of multi-inheritance and for simplicity one will typically implement this interface in base-classes of the data-model. However, maybe only some classes of the hierarchy (or even not at all) are actually revision controlled. In case of envers you can see this by looking for @Audited annotations. Also in case of mmm-persistence you will notice this by looking at the DAO.

Since:

3.0.0

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

Field Summary

Fields

Modifier and Type	Field and Description
static Number	LATEST_REVISION The latest revision of an entity.

Method Summary

Modifier and Type	Method and Description
Number	getRevision() This method gets the revision of this entity.

Methods inherited from interface net.sf.mmm.util.entity.api.GenericEntity

getId, getModificationCounter

Field Detail

LATEST_REVISION

static final Number LATEST_REVISION

The latest revision of an entity.

Method Detail

getRevision

Number getRevision()

This method gets the revision of this entity. The latest revision of an entity will always return null. Otherwise this object is a historic entity and it will be read-only so modifications are NOT permitted.

Returns:

the revision or LATEST_REVISION (null) if this is the latest revision.