org.hibernate.id

Class SequenceGenerator

java.lang.Object

org.hibernate.id.SequenceGenerator

All Implemented Interfaces:

BulkInsertionCapableIdentifierGenerator, Configurable, IdentifierGenerator, PersistentIdentifierGenerator

Direct Known Subclasses:

SequenceHiLoGenerator, SequenceIdentityGenerator

public class SequenceGenerator
extends Object
implements PersistentIdentifierGenerator, BulkInsertionCapableIdentifierGenerator, Configurable

sequence

Generates long values using an oracle-style sequence. A higher performance algorithm is SequenceHiLoGenerator.

Mapping parameters supported: sequence, parameters.

Author:

Gavin King

See Also:

SequenceHiLoGenerator

Field Summary

Fields

Modifier and Type	Field and Description
static String	PARAMETERS The parameters parameter, appended to the create sequence DDL.
static String	SEQUENCE The sequence parameter

Fields inherited from interface org.hibernate.id.PersistentIdentifierGenerator

CATALOG, IDENTIFIER_NORMALIZER, PK, SCHEMA, TABLE, TABLES

Fields inherited from interface org.hibernate.id.IdentifierGenerator

ENTITY_NAME, JPA_ENTITY_NAME

Constructor Summary

Constructors

Constructor and Description
SequenceGenerator()

Method Summary

Methods

Modifier and Type	Method and Description
protected IntegralDataTypeHolder	buildHolder()
void	configure(Type type, Properties params, Dialect dialect) Configure this instance, given the value of parameters specified by the user as <param> elements.
String	determineBulkInsertionIdentifierGenerationSelectFragment(Dialect dialect) Return the select expression fragment, if any, that generates the identifier values.
Serializable	generate(SessionImplementor session, Object obj) Generate a new identifier.
protected IntegralDataTypeHolder	generateHolder(SessionImplementor session)
Object	generatorKey() Return a key unique to the underlying database objects.
protected Type	getIdentifierType()
String	getSequenceName()
String[]	sqlCreateStrings(Dialect dialect) The SQL required to create the underlying database objects.
String[]	sqlDropStrings(Dialect dialect) The SQL required to remove the underlying database objects.
boolean	supportsBulkInsertionIdentifierGeneration() Given the configuration of this generator, is identifier generation as part of bulk insertion supported? IMPL NOTE : Mainly here to allow stuff like SequenceStyleGenerator which *can* support this based on configuration

Methods inherited from class java.lang.Object

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

Field Detail

SEQUENCE

public static final String SEQUENCE

The sequence parameter

See Also:

Constant Field Values

PARAMETERS

public static final String PARAMETERS

The parameters parameter, appended to the create sequence DDL. For example (Oracle): INCREMENT BY 1 START WITH 1 MAXVALUE 100 NOCACHE.

See Also:

Constant Field Values

Constructor Detail

SequenceGenerator

public SequenceGenerator()

Method Detail

getIdentifierType

protected Type getIdentifierType()

generatorKey

public Object generatorKey()

Description copied from interface: PersistentIdentifierGenerator

Return a key unique to the underlying database objects. Prevents us from trying to create/remove them multiple times.

Specified by:

generatorKey in interface PersistentIdentifierGenerator

Returns:

Object an identifying key for this generator

getSequenceName

public String getSequenceName()

configure

public void configure(Type type,
             Properties params,
             Dialect dialect)
               throws MappingException

Description copied from interface: Configurable

Configure this instance, given the value of parameters specified by the user as <param> elements. This method is called just once, following instantiation.

Specified by:

configure in interface Configurable

params - param values, keyed by parameter name

Throws:

MappingException

generate

public Serializable generate(SessionImplementor session,
                    Object obj)

Description copied from interface: IdentifierGenerator

Generate a new identifier.

Specified by:

generate in interface IdentifierGenerator

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

Returns:

a new identifier

generateHolder

protected IntegralDataTypeHolder generateHolder(SessionImplementor session)

buildHolder

protected IntegralDataTypeHolder buildHolder()

sqlCreateStrings

public String[] sqlCreateStrings(Dialect dialect)
                          throws HibernateException

Description copied from interface: PersistentIdentifierGenerator

The SQL required to create the underlying database objects.

Specified by:

sqlCreateStrings in interface PersistentIdentifierGenerator

Parameters:

dialect - The dialect against which to generate the create command(s)

Returns:

The create command(s)

Throws:

HibernateException - problem creating the create command(s)

sqlDropStrings

public String[] sqlDropStrings(Dialect dialect)
                        throws HibernateException

Description copied from interface: PersistentIdentifierGenerator

The SQL required to remove the underlying database objects.

Specified by:

sqlDropStrings in interface PersistentIdentifierGenerator

Parameters:

dialect - The dialect against which to generate the drop command(s)

Returns:

The drop command(s)

Throws:

HibernateException - problem creating the drop command(s)

supportsBulkInsertionIdentifierGeneration

public boolean supportsBulkInsertionIdentifierGeneration()

Description copied from interface: BulkInsertionCapableIdentifierGenerator

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

IMPL NOTE : Mainly here to allow stuff like SequenceStyleGenerator which *can* support this based on configuration

Specified by:

supportsBulkInsertionIdentifierGeneration in interface BulkInsertionCapableIdentifierGenerator

Returns:

true if bulk insertions are supported; false otherwise.

determineBulkInsertionIdentifierGenerationSelectFragment

public String determineBulkInsertionIdentifierGenerationSelectFragment(Dialect dialect)

Description copied from interface: BulkInsertionCapableIdentifierGenerator

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

Specified by:

determineBulkInsertionIdentifierGenerationSelectFragment in interface BulkInsertionCapableIdentifierGenerator

Parameters:

dialect - The dialect against which the insert will be performed.

Returns:

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