Class GenericGeneratorGeneration

java.lang.Object

org.hibernate.id.GenericGeneratorGeneration

All Implemented Interfaces:

Serializable, ExportableProducer, AnnotationBasedGenerator<GenericGenerator>, BeforeExecutionGenerator, Generator, OnExecutionGenerator, BulkInsertionCapableIdentifierGenerator, Configurable, IdentifierGenerator

@Internal
public class GenericGeneratorGeneration
extends Object
implements IdentifierGenerator, OnExecutionGenerator, BulkInsertionCapableIdentifierGenerator, AnnotationBasedGenerator<GenericGenerator>

Generator backing GenericGenerator.

Since:

8.0

See Also:

• Serialized Form

Field Summary

Fields inherited from interface IdentifierGenerator

CONTRIBUTOR_NAME, ENTITY_NAME, GENERATOR_NAME, JPA_ENTITY_NAME

Constructor Summary

Constructors

Constructor	Description
GenericGeneratorGeneration()

Method Summary

Modifier and Type	Method	Description
boolean	allowAssignedIdentifiers()	Determine if this generator allows identifier values to be manually assigned to the entity instance before persisting it.
boolean	allowMutation()	Determine if this generator allows generated fields to be manually assigned a value on events which do not trigger value generation.
String	determineBulkInsertionIdentifierGenerationSelectFragment(SqlStringGenerationContext context)	Return the select expression fragment, if any, that generates the identifier values.
Object	generate(SharedSessionContractImplementor session, Object object)	Generate a new identifier.
Object	generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType)	Generate a value.
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.
Generator	getDelegate()
EnumSet<EventType>	getEventTypes()	The event types for which this generator should be called to produce a new value.
InsertGeneratedIdentifierDelegate	getGeneratedIdentifierDelegate(EntityPersister persister)	The InsertGeneratedIdentifierDelegate used to retrieve the generated value if this object is an identifier generator.
Class<?>	getGeneratedType()	The Java type of the generated values.
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.
String[]	getUniqueKeyPropertyNames(EntityPersister persister)	The name of a property of the entity which may be used to locate the just-inserted row containing the generated value.
void	initialize(GenericGenerator annotation, GeneratorCreationContext context)	Initializes this generation strategy for the given annotation instance.
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.
boolean	requiresIdentityColumn()	Does this generator require an identity (autoincrement) column.
boolean	supportsBulkInsertionIdentifierGeneration()	Given the configuration of this generator, is identifier generation as part of bulk insertion supported?
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 AnnotationBasedGenerator

initialize

Methods inherited from interface Configurable

configure, initialize

Methods inherited from interface Generator

generatesOnForceIncrement, generatesOnInsert, generatesOnUpdate, generatesSometimes

Methods inherited from interface IdentifierGenerator

configure, registerExportables

Constructor Details

GenericGeneratorGeneration

public GenericGeneratorGeneration()

Method Details

getDelegate

@Internal
public Generator getDelegate()

initialize

public void initialize(GenericGenerator annotation,
 GeneratorCreationContext context)

Description copied from interface: AnnotationBasedGenerator

Initializes this generation strategy for the given annotation instance.

Specified by:

initialize in interface AnnotationBasedGenerator<GenericGenerator>

Parameters:

annotation - an instance of the strategy's annotation type. Typically, implementations will retrieve the annotation's attribute values and store them in fields.

context - a GeneratorCreationContext

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

getEventTypes

public EnumSet<EventType> getEventTypes()

Description copied from interface: Generator

The event types for which this generator should be called to produce a new value.

Identifier generators must return EventTypeSets.INSERT_ONLY.

Specified by:

getEventTypes in interface Generator

Specified by:

getEventTypes in interface IdentifierGenerator

Returns:

EventTypeSets.INSERT_ONLY

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

allowAssignedIdentifiers

public boolean allowAssignedIdentifiers()

Description copied from interface: Generator

Determine if this generator allows identifier values to be manually assigned to the entity instance before persisting it. This is useful when, for example, needing existing assigned values to be used as identifiers and falling back to generated values by default.

Specified by:

allowAssignedIdentifiers in interface Generator

Returns:

true if this generator allows pre-assigned identifier values, false otherwise (default).

allowMutation

public boolean allowMutation()

Description copied from interface: Generator

Determine if this generator allows generated fields to be manually assigned a value on events which do not trigger value generation.

Specified by:

allowMutation in interface Generator

Returns:

true if this generator allows manually assigned values, false otherwise (default).

requiresIdentityColumn

public boolean requiresIdentityColumn()

Description copied from interface: Generator

Does this generator require an identity (autoincrement) column.

Specified by:

requiresIdentityColumn in interface Generator

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

generate

public Object generate(SharedSessionContractImplementor session,
 Object owner,
 Object currentValue,
 EventType eventType)

Description copied from interface: IdentifierGenerator

Generate a value.

The currentValue is usually null for id generation.

Specified by:

generate in interface BeforeExecutionGenerator

Specified by:

generate in interface IdentifierGenerator

Parameters:

session - The session from which the request originates.

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

currentValue - The current value assigned to the property, or null

eventType - The type of event that has triggered generation of a new value

Returns:

The generated value

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

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

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

getUniqueKeyPropertyNames

public String[] getUniqueKeyPropertyNames(EntityPersister persister)

Description copied from interface: OnExecutionGenerator

The name of a property of the entity which may be used to locate the just-inserted row containing the generated value. Of course, the columns mapped by this property should form a unique key of the entity.

The default implementation uses the @NaturalId property, if there is one.

Specified by:

getUniqueKeyPropertyNames in interface OnExecutionGenerator

supportsBulkInsertionIdentifierGeneration

public boolean supportsBulkInsertionIdentifierGeneration()

Description copied from interface: BulkInsertionCapableIdentifierGenerator

Given the configuration of this generator, is identifier generation as part of bulk insertion supported?

Specified by:

supportsBulkInsertionIdentifierGeneration in interface BulkInsertionCapableIdentifierGenerator

Returns:

true if bulk insertions are supported; false otherwise.

determineBulkInsertionIdentifierGenerationSelectFragment

public String determineBulkInsertionIdentifierGenerationSelectFragment(SqlStringGenerationContext context)

Description copied from interface: BulkInsertionCapableIdentifierGenerator

Return the select expression fragment, if any, that generates the identifier values.

Specified by:

determineBulkInsertionIdentifierGenerationSelectFragment in interface BulkInsertionCapableIdentifierGenerator

Returns:

The identifier value generation fragment (SQL). null indicates that no fragment is needed.