org.hibernate.id
Class CompositeNestedGeneratedValueGenerator

java.lang.Object
  org.hibernate.id.CompositeNestedGeneratedValueGenerator

All Implemented Interfaces:

Serializable, IdentifierGenerator, IdentifierGeneratorAggregator

public class CompositeNestedGeneratedValueGenerator
extends Object
implements IdentifierGenerator, Serializable, IdentifierGeneratorAggregator

For composite identifiers, defines a number of "nested" generations that need to happen to "fill" the identifier property(s).

This generator is used implicitly for all composite identifier scenarios if an explicit generator is not in place. So it make sense to discuss the various potential scenarios:

• "embedded" composite identifier - this is possible only in HBM mappings as <composite-id/> (notice the lack of both a name and class attribute declarations). The term "embedded" here refers to the Hibernate usage which is actually the exact opposite of the JPA meaning of "embedded". Essentially this means that the entity class itself holds the named composite pk properties. This is very similar to the JPA @IdClass usage, though without a separate pk-class for loading.
• pk-class as entity attribute - this is possible in both annotations (@EmbeddedId) and HBM mappings (<composite-id name="idAttributeName" class="PkClassName"/>)
• "embedded" composite identifier with a pk-class - this is the JPA @IdClass use case and is only possible in annotations

Most of the grunt work is done in Component.

Author:

Steve Ebersole

See Also:

Serialized Form

Nested Class Summary

static interface	CompositeNestedGeneratedValueGenerator.GenerationContextLocator Contract for declaring how to locate the context for sub-value injection.
static interface	CompositeNestedGeneratedValueGenerator.GenerationPlan Contract for performing the actual sub-value generation, usually injecting it into the determined context

Field Summary

Fields inherited from interface org.hibernate.id.IdentifierGenerator

ENTITY_NAME

Constructor Summary

CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator)

Method Summary

void	addGeneratedValuePlan(CompositeNestedGeneratedValueGenerator.GenerationPlan plan)
Serializable	generate(SessionImplementor session, Object object) Generate a new identifier.
void	registerPersistentGenerators(Map generatorMap) Register any sub generators which implement PersistentIdentifierGenerator by their generatorKey.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CompositeNestedGeneratedValueGenerator

public CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator)

Method Detail

addGeneratedValuePlan

public void addGeneratedValuePlan(CompositeNestedGeneratedValueGenerator.GenerationPlan plan)

generate

public Serializable generate(SessionImplementor session,
                             Object object)
                      throws HibernateException

Description copied from interface: IdentifierGenerator

Generate a new identifier.

Specified by:

generate in interface IdentifierGenerator

object - the entity or toplevel collection for which the id is being generated

Returns:

a new identifier

Throws:

HibernateException

registerPersistentGenerators

public void registerPersistentGenerators(Map generatorMap)

Register any sub generators which implement PersistentIdentifierGenerator by their generatorKey.

Specified by:

registerPersistentGenerators in interface IdentifierGeneratorAggregator

Parameters:

generatorMap - The map of generators.