CompositeNestedGeneratedValueGenerator (Hibernate JavaDocs)

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

All Implemented Interfaces:

java.io.Serializable, ExportableProducer, IdentifierGenerator, IdentifierGeneratorAggregator
```
public class CompositeNestedGeneratedValueGenerator
extends java.lang.Object
implements IdentifierGenerator, java.io.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	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 Description

CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addGeneratedValuePlan(CompositeNestedGeneratedValueGenerator.GenerationPlan plan)`
`java.io.Serializable`	`generate(SharedSessionContractImplementor session, java.lang.Object object)`	Generate a new identifier.
`void`	`registerExportables(Database database)`	Register the contained exportable things to the `Database`

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
supportsJdbcBatchInserts

- Constructor Detail
  - CompositeNestedGeneratedValueGenerator
```
public CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator)
```
- Method Detail
  - addGeneratedValuePlan
```
public void addGeneratedValuePlan(CompositeNestedGeneratedValueGenerator.GenerationPlan plan)
```
  - generate
```
public java.io.Serializable generate(SharedSessionContractImplementor session,
                                     java.lang.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: ExportableProducer
    
    Register the contained exportable things to the Database
    
    Specified by:
    
    registerExportables in interface ExportableProducer
    
    Parameters:
    
    database - The database instance