org.hibernate.id
Class MultipleHiLoPerTableGenerator

java.lang.Object
  org.hibernate.id.MultipleHiLoPerTableGenerator

All Implemented Interfaces:

Configurable, IdentifierGenerator, PersistentIdentifierGenerator

public class MultipleHiLoPerTableGenerator
extends Object
implements PersistentIdentifierGenerator, Configurable

A hilo IdentifierGenerator that returns a Long, constructed using a hi/lo algorithm. The hi value MUST be fetched in a seperate transaction to the Session transaction so the generator must be able to obtain a new connection and commit it. Hence this implementation may not be used when the user is supplying connections. In this case a SequenceHiLoGenerator would be a better choice (where supported).

A hilo IdentifierGenerator that uses a database table to store the last generated values. A table can contains several hi values. They are distinct from each other through a key

This implementation is not compliant with a user connection

Allowed parameters (all of them are optional):

• table: table name (default hibernate_sequences)
• primary_key_column: key column name (default sequence_name)
• value_column: hi value column name(default sequence_next_hi_value)
• primary_key_value: key value for the current entity (default to the entity's primary table name)
• primary_key_length: length of the key column in DB represented as a varchar (default to 255)
• max_lo: max low value before increasing hi (default to Short.MAX_VALUE)

Field Summary

static String	DEFAULT_TABLE
static String	ID_TABLE
static String	MAX_LO
static String	PK_COLUMN_NAME
static String	PK_LENGTH_NAME
static String	PK_VALUE_NAME
static String	VALUE_COLUMN_NAME

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

MultipleHiLoPerTableGenerator()

Method Summary

void	configure(Type type, Properties params, Dialect dialect) Configure this instance, given the value of parameters specified by the user as <param> elements.
Serializable	generate(SessionImplementor session, Object obj) Generate a new identifier.
Object	generatorKey() Return a key unique to the underlying database objects.
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.

Methods inherited from class java.lang.Object

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

Field Detail

ID_TABLE

public static final String ID_TABLE

See Also:

Constant Field Values

PK_COLUMN_NAME

public static final String PK_COLUMN_NAME

See Also:

Constant Field Values

PK_VALUE_NAME

public static final String PK_VALUE_NAME

See Also:

Constant Field Values

VALUE_COLUMN_NAME

public static final String VALUE_COLUMN_NAME

See Also:

Constant Field Values

PK_LENGTH_NAME

public static final String PK_LENGTH_NAME

See Also:

Constant Field Values

DEFAULT_TABLE

public static final String DEFAULT_TABLE

See Also:

Constant Field Values

MAX_LO

public static final String MAX_LO

See Also:

Constant Field Values

Constructor Detail

MultipleHiLoPerTableGenerator

public MultipleHiLoPerTableGenerator()

Method Detail

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)

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

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

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