org.hibernate.id

Class CompositeNestedGeneratedValueGenerator

java.lang.Object

org.hibernate.id.CompositeNestedGeneratedValueGenerator

All Implemented Interfaces:

Serializable, ExportableProducer, Configurable, 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.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
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, GENERATOR_NAME, JPA_ENTITY_NAME

Constructor Summary

Constructors

Constructor and Description
CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator)

Method Summary

Modifier and Type	Method and Description
void	addGeneratedValuePlan(CompositeNestedGeneratedValueGenerator.GenerationPlan plan)
Serializable	generate(SharedSessionContractImplementor session, Object object) Generate a new identifier.
void	initialize(SqlStringGenerationContext context) Initializes this instance, in particular pre-generates SQL as necessary.
void	registerExportables(Database database) Register database objects used by this identifier generator, e.g.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.hibernate.id.IdentifierGenerator

configure, supportsJdbcBatchInserts

Constructor Detail

CompositeNestedGeneratedValueGenerator

public CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator)

Method Detail

addGeneratedValuePlan

public void addGeneratedValuePlan(CompositeNestedGeneratedValueGenerator.GenerationPlan plan)

generate

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

Description copied from interface: IdentifierGenerator

Generate a new identifier.

Specified by:

generate in interface IdentifierGenerator

Parameters:

session - The session from which the request originates

object - the entity or collection (idbag) for which the id is being generated

Returns:

a new identifier

Throws:

HibernateException - Indicates trouble generating the identifier

registerExportables

public void registerExportables(Database database)

Description copied from interface: IdentifierGenerator

Register database objects used by this identifier generator, e.g. sequences, tables, etc.

This method is called just once, after IdentifierGenerator.configure(Type, Properties, ServiceRegistry).

Specified by:

registerExportables in interface ExportableProducer

Specified by:

registerExportables in interface IdentifierGenerator

Parameters:

database - The database instance

initialize

public void initialize(SqlStringGenerationContext context)

Description copied from interface: IdentifierGenerator

Initializes this instance, in particular pre-generates SQL as necessary.

This method is called after IdentifierGenerator.registerExportables(Database), before first use.

Specified by:

initialize in interface IdentifierGenerator

Parameters:

context - A context to help generate SQL strings