Package org.hibernate.id

Class IncrementGenerator

java.lang.Object

org.hibernate.id.IncrementGenerator

All Implemented Interfaces:

Serializable, ExportableProducer, BeforeExecutionGenerator, Generator, Configurable, StandardGenerator, IdentifierGenerator

public class IncrementGenerator
extends Object
implements IdentifierGenerator, StandardGenerator

An IdentifierGenerator that returns a long, constructed by counting from the maximum primary key value obtained by querying the table or tables at startup.

This id generator is not safe unless a single VM has exclusive access to the database.

Mapping parameters supported, but not usually needed: "tables", "column". (The "tables" parameter specifies a comma-separated list of table names.)

See Also:

Serialized Form

Implementation Note:

This also implements the increment generation type in hbm.xml mappings.

Field Summary

Fields

Modifier and Type	Field	Description
static String	COLUMN	A parameter identifying the column holding the id.
static String	TABLES	A parameter specifying a list of tables over which the generated id should be unique.

Fields inherited from interface org.hibernate.id.IdentifierGenerator

CONTRIBUTOR_NAME, ENTITY_NAME, GENERATOR_NAME, JPA_ENTITY_NAME

Constructor Summary

Constructors

Constructor	Description
IncrementGenerator()

Method Summary

Modifier and Type	Method	Description
void	configure(Type type, Properties parameters, ServiceRegistry serviceRegistry)	Configure this instance, given the value of parameters specified by the user as <param> elements.
Object	generate(SharedSessionContractImplementor session, Object object)	Generate a new identifier.
String[]	getAllSqlForTests()	Deprecated. Exposed for tests only.
void	initialize(SqlStringGenerationContext context)	Initializes this instance, in particular pre-generates SQL as necessary.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.hibernate.generator.BeforeExecutionGenerator

generatedOnExecution

Methods inherited from interface org.hibernate.generator.Generator

generatedOnExecution, generatesOnInsert, generatesOnUpdate, generatesSometimes

Methods inherited from interface org.hibernate.id.IdentifierGenerator

generate, getEventTypes, registerExportables, supportsJdbcBatchInserts

Field Detail

COLUMN

public static final String COLUMN

A parameter identifying the column holding the id.

See Also:

Constant Field Values

TABLES

public static final String TABLES

A parameter specifying a list of tables over which the generated id should be unique.

See Also:

Constant Field Values

Constructor Detail

IncrementGenerator

public IncrementGenerator()

Method Detail

getAllSqlForTests

@Deprecated
public String[] getAllSqlForTests()

Deprecated.

Exposed for tests only.

generate

public Object generate(SharedSessionContractImplementor session,
                       Object object)
                throws HibernateException

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

Throws:

HibernateException - Indicates trouble generating the identifier

configure

public void configure(Type type,
                      Properties parameters,
                      ServiceRegistry serviceRegistry)
               throws MappingException

Description copied from interface: IdentifierGenerator

Configure this instance, given the value of parameters specified by the user as <param> elements.

This method is called just once, following instantiation, and before IdentifierGenerator.registerExportables(Database).

Specified by:

configure in interface Configurable

Specified by:

configure in interface IdentifierGenerator

Parameters:

type - The id property type descriptor

parameters - param values, keyed by parameter name

serviceRegistry - Access to service that may be needed.

Throws:

MappingException - If configuration fails.

initialize

public void initialize(SqlStringGenerationContext context)

Description copied from interface: IdentifierGenerator

Initializes this instance, in particular pre-generates SQL as necessary.

This method is called after IdentifierGenerator.registerExportables(Database), and before first use.

Specified by:

initialize in interface IdentifierGenerator

Parameters:

context - A context to help generate SQL strings