Package org.hibernate.id

Class TableGenerator

java.lang.Object

org.hibernate.engine.TransactionHelper

org.hibernate.id.TableGenerator

All Implemented Interfaces:

Configurable, IdentifierGenerator, PersistentIdentifierGenerator

Direct Known Subclasses:

TableHiLoGenerator

public class TableGenerator
extends TransactionHelper
implements PersistentIdentifierGenerator, Configurable

An IdentifierGenerator that uses a database table to store the last generated value. It is not intended that applications use this strategy directly. However, it may be used to build other (efficient) strategies. The returned type is any supported by IntegralDataTypeHolder

The value MUST be fetched in a separate transaction from that of the main session transaction so the generator must be able to obtain a new connection and commit it. Hence this implementation may only be used when Hibernate is fetching connections, not when the user is supplying connections.

Again, the return types supported here are any of the ones supported by IntegralDataTypeHolder. This is new as of 3.5. Prior to that this generator only returned Integer values.

Mapping parameters supported: table, column

See Also:

• TableHiLoGenerator

Field Summary

Fields

Modifier and Type	Field	Description
static final String	COLUMN	The column parameter
static final String	DEFAULT_COLUMN_NAME	Default column name
static final String	DEFAULT_TABLE_NAME	Default table name
static final String	TABLE	The table parameter

Fields inherited from interface org.hibernate.id.IdentifierGenerator

ENTITY_NAME

Fields inherited from interface org.hibernate.id.PersistentIdentifierGenerator

CATALOG, IDENTIFIER_NORMALIZER, PK, SCHEMA, SQL_STATEMENT_LOGGER, TABLES

Constructor Summary

Constructors

Constructor	Description
TableGenerator()

Method Summary

Modifier and Type	Method	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.
Serializable	doWorkInCurrentTransaction(Connection conn, String sql)	Get the next value.
Serializable	generate(SessionImplementor session, Object object)	Generate a new identifier.
protected IntegralDataTypeHolder	generateHolder(SessionImplementor session)
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 org.hibernate.engine.TransactionHelper

doWorkInNewTransaction

Methods inherited from class java.lang.Object

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

Field Details

COLUMN

public static final String COLUMN

The column parameter

See Also:

• Constant Field Values

DEFAULT_COLUMN_NAME

public static final String DEFAULT_COLUMN_NAME

Default column name

See Also:

• Constant Field Values

TABLE

public static final String TABLE

The table parameter

See Also:

• Constant Field Values

DEFAULT_TABLE_NAME

public static final String DEFAULT_TABLE_NAME

Default table name

See Also:

• Constant Field Values

Constructor Details

TableGenerator

public TableGenerator()

Method Details

configure

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

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

Parameters:

params - param values, keyed by parameter name

generate

public Serializable generate(SessionImplementor session,
 Object object)

Description copied from interface: IdentifierGenerator

Generate a new identifier.

Specified by:

generate in interface IdentifierGenerator

Parameters:

session -

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

Returns:

a new identifier

generateHolder

protected IntegralDataTypeHolder generateHolder(SessionImplementor session)

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)

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)

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

doWorkInCurrentTransaction

public Serializable doWorkInCurrentTransaction(Connection conn,
 String sql)
                                        throws SQLException

Get the next value.

Specified by:

doWorkInCurrentTransaction in class TransactionHelper

Parameters:

conn - The sql connection to use.

sql - n/a

Returns:

Prior to 3.5 this method returned an Integer. Since 3.5 it now returns a IntegralDataTypeHolder

Throws:

SQLException

buildHolder

protected IntegralDataTypeHolder buildHolder()