Class CompositeNestedGeneratedValueGenerator

java.lang.Object

org.hibernate.id.CompositeNestedGeneratedValueGenerator

All Implemented Interfaces:

Serializable, ExportableProducer, BeforeExecutionGenerator, Generator, OnExecutionGenerator, Configurable, IdentifierGenerator, IdentifierGeneratorAggregator

@Internal
public class CompositeNestedGeneratedValueGenerator
extends Object
implements IdentifierGenerator, IdentifierGeneratorAggregator, OnExecutionGenerator, Serializable

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 IdentifierGenerator

CONTRIBUTOR_NAME, ENTITY_NAME, GENERATOR_NAME, JPA_ENTITY_NAME

Constructor Summary

Constructors

Constructor	Description
CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator, ComponentType componentType)
CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator, ComponentType componentType, List<Generator> generators, String[] columnValues, boolean[] columnInclusions, boolean[] generatedOnExecutionColumns)
CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator original, List<CompositeNestedGeneratedValueGenerator.GenerationPlan> generationPlans)

Method Summary

Modifier and Type	Method	Description
void	addGeneratedValuePlan(CompositeNestedGeneratedValueGenerator.GenerationPlan plan)
Object	generate(SharedSessionContractImplementor session, Object object)	Generate a new identifier.
boolean	generatedBeforeExecution(Object entity, SharedSessionContractImplementor session)	Determines if the property value is generated before in Java code that executes before the row is written.
boolean	generatedOnExecution()	Determines if the property value is generated when a row is written to the database, or in Java code that executes before the row is written.
boolean	generatedOnExecution(Object entity, SharedSessionContractImplementor session)	Determines if the property value is generated when a row is written to the database.
boolean[]	getColumnInclusions(Dialect dialect, EventType eventType)	Indicates which columns should be included in SQL for the given event type.
ComponentType	getComponentType()
InsertGeneratedIdentifierDelegate	getGeneratedIdentifierDelegate(EntityPersister persister)	The InsertGeneratedIdentifierDelegate used to retrieve the generated value if this object is an identifier generator.
boolean[]	getGeneratedOnExecutionColumnInclusions()
Class<?>	getGeneratedType()	The Java type of the generated values.
CompositeNestedGeneratedValueGenerator.GenerationContextLocator	getGenerationContextLocator()
List<CompositeNestedGeneratedValueGenerator.GenerationPlan>	getGenerationPlans()
String[]	getReferencedColumnValues(Dialect dialect)	A SQL expression indicating how to calculate the generated values when the mapped columns are included in the SQL statement.
String[]	getReferencedColumnValues(Dialect dialect, EventType eventType)	A SQL expression indicating how to calculate the generated values when the mapped columns are included in the SQL statement for the given event type.
boolean	hasAssignedValues()
void	initialize(SqlStringGenerationContext context)	Initializes this instance, pre-generating SQL if necessary.
boolean	referenceColumnsInSql(Dialect dialect)	Determines if the columns whose values are generated are included in the column list of the SQL insert or update statement.
boolean	referenceColumnsInSql(Dialect dialect, EventType eventType)	Determines if the columns whose values are generated are included in the column list of the SQL insert or update statement for the given event type.
void	registerExportables(Database database)	Register database objects used by this identifier generator, for example, a sequence or tables.
boolean	writePropertyValue()	Determines if the property values are written to JDBC as the argument of a JDBC ? parameter.
boolean	writePropertyValue(EventType eventType)	Determines if the property values are written to JDBC as the argument of a JDBC ? parameter for the given event type.

Methods inherited from class Object

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

Methods inherited from interface Configurable

configure

Methods inherited from interface Generator

allowAssignedIdentifiers, allowMutation, generatesOnForceIncrement, generatesOnInsert, generatesOnUpdate, generatesSometimes

Methods inherited from interface IdentifierGenerator

configure, generate, getEventTypes

Methods inherited from interface OnExecutionGenerator

getUniqueKeyPropertyNames

Constructor Details

CompositeNestedGeneratedValueGenerator

public CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator,
 ComponentType componentType)

CompositeNestedGeneratedValueGenerator

public CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator original,
 List<CompositeNestedGeneratedValueGenerator.GenerationPlan> generationPlans)

CompositeNestedGeneratedValueGenerator

public CompositeNestedGeneratedValueGenerator(CompositeNestedGeneratedValueGenerator.GenerationContextLocator generationContextLocator,
 ComponentType componentType,
 List<Generator> generators,
 String[] columnValues,
 boolean[] columnInclusions,
 boolean[] generatedOnExecutionColumns)

Method Details

addGeneratedValuePlan

public void addGeneratedValuePlan(CompositeNestedGeneratedValueGenerator.GenerationPlan plan)

hasAssignedValues

public boolean hasAssignedValues()

generate

public Object generate(SharedSessionContractImplementor session,
 Object object)

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

getGeneratedType

public Class<?> getGeneratedType()

Description copied from interface: Generator

The Java type of the generated values.

Specified by:

getGeneratedType in interface Generator

Returns:

the generated type, or null if the type is not known

registerExportables

public void registerExportables(Database database)

Description copied from interface: IdentifierGenerator

Register database objects used by this identifier generator, for example, a sequence or tables.

This method is called just once, after Configurable.configure(GeneratorCreationContext, Properties).

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: Configurable

Initializes this instance, pre-generating SQL if necessary.

If this instance also implements ExportableProducer, then this method is always called after ExportableProducer.registerExportables(Database), and before first use.

Specified by:

initialize in interface Configurable

Parameters:

context - A context to help generate SQL strings

generatedOnExecution

public boolean generatedOnExecution()

Description copied from interface: Generator

Determines if the property value is generated when a row is written to the database, or in Java code that executes before the row is written.

• Generators which only implement BeforeExecutionGenerator must result false.
• Generators which only implement OnExecutionGenerator must result true.
• Generators which implement both subinterfaces may decide at runtime what value to return.

Specified by:

generatedOnExecution in interface BeforeExecutionGenerator

Specified by:

generatedOnExecution in interface Generator

Specified by:

generatedOnExecution in interface OnExecutionGenerator

Returns:

true if the value is generated by the database as a side effect of the execution of an insert or update statement, or false if it is generated in Java code before the statement is executed via JDBC.

generatedOnExecution

public boolean generatedOnExecution(Object entity,
 SharedSessionContractImplementor session)

Description copied from interface: Generator

Determines if the property value is generated when a row is written to the database.

Defaults to Generator.generatedOnExecution(), but may be overridden to allow conditional on-execution value generation based on the current state of the owner entity.

Specified by:

generatedOnExecution in interface Generator

Parameters:

entity - The instance of the entity owning the attribute for which we are generating a value.

session - The session from which the request originates.

Returns:

true if the value is generated by the database as a side effect of the execution of an insert or update statement.

See Also:

• Generator.generatedOnExecution()
• BeforeExecutionGenerator
• OnExecutionGenerator

generatedBeforeExecution

public boolean generatedBeforeExecution(Object entity,
 SharedSessionContractImplementor session)

Description copied from interface: Generator

Determines if the property value is generated before in Java code that executes before the row is written.

Defaults to !generatedOnExecution(), but may be overridden to allow conditional before-execution value generation based on the current state of the owner entity.

Specified by:

generatedBeforeExecution in interface Generator

Parameters:

entity - The instance of the entity owning the attribute for which we are generating a value.

session - The session from which the request originates.

Returns:

true if the value is generated in Java code before the statement is executed via JDBC.

See Also:

• Generator.generatedOnExecution()
• BeforeExecutionGenerator
• OnExecutionGenerator

referenceColumnsInSql

public boolean referenceColumnsInSql(Dialect dialect)

Description copied from interface: OnExecutionGenerator

Determines if the columns whose values are generated are included in the column list of the SQL insert or update statement. For example, this method should return:

• true if the value is generated by calling a SQL function like current_timestamp, or
• false if the value is generated by a trigger, by generated always as, or using a column default value.

Specified by:

referenceColumnsInSql in interface OnExecutionGenerator

Returns:

true if the column is included in the column list of the SQL statement.

referenceColumnsInSql

public boolean referenceColumnsInSql(Dialect dialect,
 EventType eventType)

Description copied from interface: OnExecutionGenerator

Determines if the columns whose values are generated are included in the column list of the SQL insert or update statement for the given event type.

The default implementation delegates to OnExecutionGenerator.referenceColumnsInSql(Dialect).

Specified by:

referenceColumnsInSql in interface OnExecutionGenerator

writePropertyValue

public boolean writePropertyValue()

Description copied from interface: OnExecutionGenerator

Determines if the property values are written to JDBC as the argument of a JDBC ? parameter.

Specified by:

writePropertyValue in interface OnExecutionGenerator

writePropertyValue

public boolean writePropertyValue(EventType eventType)

Description copied from interface: OnExecutionGenerator

Determines if the property values are written to JDBC as the argument of a JDBC ? parameter for the given event type.

The default implementation delegates to OnExecutionGenerator.writePropertyValue().

Specified by:

writePropertyValue in interface OnExecutionGenerator

getGeneratedIdentifierDelegate

public InsertGeneratedIdentifierDelegate getGeneratedIdentifierDelegate(EntityPersister persister)

Description copied from interface: OnExecutionGenerator

The InsertGeneratedIdentifierDelegate used to retrieve the generated value if this object is an identifier generator.

This is ignored by GeneratedValuesProcessor, which handles multiple generators at once. So if this object is not an identifier generator, this method is never called.

Note that this method arguably breaks the separation of concerns between the generator and coordinating code, by specifying how the generated value should be retrieved.

The problem solved here is: we want to obtain an insert-generated primary key. But, sadly, without already knowing the primary key, there's no completely-generic way to locate the just-inserted row to obtain it.

We need one of the following things:

• a database which supports some form of insert ... returning syntax, or can do the same thing using the JDBC getGeneratedKeys() API, or
• a second unique key of the entity, that is, a property annotated @NaturalId.

Alternatively, if the generated id is an identity/"autoincrement" column, we can take advantage of special platform-specific functionality to retrieve it. Taking advantage of the specialness of identity columns is the job of one particular implementation: IdentityGenerator. And the need for customized behavior for identity columns is the reason why this layer-breaking method exists.

Specified by:

getGeneratedIdentifierDelegate in interface OnExecutionGenerator

getReferencedColumnValues

public String[] getReferencedColumnValues(Dialect dialect)

Description copied from interface: OnExecutionGenerator

A SQL expression indicating how to calculate the generated values when the mapped columns are included in the SQL statement. The SQL expressions might be:

• function calls like current_timestamp or nextval('mysequence'), or
• syntactic markers like default.

Specified by:

getReferencedColumnValues in interface OnExecutionGenerator

Parameters:

dialect - The SQL dialect, allowing generation of an expression in dialect-specific SQL.

Returns:

The column value to be used in the generated SQL statement.

getReferencedColumnValues

public String[] getReferencedColumnValues(Dialect dialect,
 EventType eventType)

Description copied from interface: OnExecutionGenerator

A SQL expression indicating how to calculate the generated values when the mapped columns are included in the SQL statement for the given event type.

The default implementation delegates to OnExecutionGenerator.getReferencedColumnValues(Dialect).

Specified by:

getReferencedColumnValues in interface OnExecutionGenerator

getColumnInclusions

public boolean[] getColumnInclusions(Dialect dialect,
 EventType eventType)

Description copied from interface: OnExecutionGenerator

Indicates which columns should be included in SQL for the given event type. A null return value indicates that all columns are included.

Specified by:

getColumnInclusions in interface OnExecutionGenerator

getGenerationPlans

public List<CompositeNestedGeneratedValueGenerator.GenerationPlan> getGenerationPlans()

getGenerationContextLocator

public CompositeNestedGeneratedValueGenerator.GenerationContextLocator getGenerationContextLocator()

getComponentType

public ComponentType getComponentType()

getGeneratedOnExecutionColumnInclusions

public boolean[] getGeneratedOnExecutionColumnInclusions()