站内搜索: 请输入搜索关键词
当前页面: 在线文档首页 > Hibernate 3.2.3 正式版 API 英文文档

SequenceStyleGenerator (Hibernate API Documentation) - Hibernate 3.2.3 正式版 API 英文文档


org.hibernate.id.enhanced
Class SequenceStyleGenerator

java.lang.Object
  extended byorg.hibernate.id.enhanced.SequenceStyleGenerator
All Implemented Interfaces:
Configurable, IdentifierGenerator, PersistentIdentifierGenerator

public class SequenceStyleGenerator
extends Object
implements PersistentIdentifierGenerator, Configurable

Generates identifier values based on an sequence-style database structure. Variations range from actually using a sequence to using a table to mimic a sequence. These variations are encapsulated by the DatabaseStructure interface internally.

General configuration parameters:
NAME DEFAULT DESCRIPTION
SEQUENCE_PARAM DEF_SEQUENCE_NAME The name of the sequence/table to use to store/retrieve values
INITIAL_PARAM DEFAULT_INITIAL_VALUE The initial value to be stored for the given segment; the effect in terms of storage varies based on Optimizer and DatabaseStructure
INCREMENT_PARAM DEFAULT_INCREMENT_SIZE The increment size for the underlying segment; the effect in terms of storage varies based on Optimizer and DatabaseStructure
OPT_PARAM depends on defined increment size Allows explicit definition of which optimization strategy to use
FORCE_TBL_PARAM false Allows explicit definition of which optimization strategy to use

Configuration parameters used specifically when the underlying structure is a table:
NAME DEFAULT DESCRIPTION
VALUE_COLUMN_PARAM DEF_VALUE_COLUMN The name of column which holds the sequence value for the given segment

Author:
Steve Ebersole

Field Summary
static String DEF_SEQUENCE_NAME
           
static String DEF_VALUE_COLUMN
           
static int DEFAULT_INCREMENT_SIZE
           
static int DEFAULT_INITIAL_VALUE
           
static String FORCE_TBL_PARAM
           
static String INCREMENT_PARAM
           
static String INITIAL_PARAM
           
static String OPT_PARAM
           
static String SEQUENCE_PARAM
           
static String VALUE_COLUMN_PARAM
           
 
Fields inherited from interface org.hibernate.id.PersistentIdentifierGenerator
CATALOG, PK, SCHEMA, SQL, TABLE, TABLES
 
Fields inherited from interface org.hibernate.id.IdentifierGenerator
ENTITY_NAME
 
Constructor Summary
SequenceStyleGenerator()
           
 
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 object)
          Generate a new identifier.
 Object generatorKey()
          Return a key unique to the underlying database objects.
 DatabaseStructure getDatabaseStructure()
           
 Type getIdentifierType()
           
 Optimizer getOptimizer()
           
 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

SEQUENCE_PARAM

public static final String SEQUENCE_PARAM
See Also:
Constant Field Values

DEF_SEQUENCE_NAME

public static final String DEF_SEQUENCE_NAME
See Also:
Constant Field Values

INITIAL_PARAM

public static final String INITIAL_PARAM
See Also:
Constant Field Values

DEFAULT_INITIAL_VALUE

public static final int DEFAULT_INITIAL_VALUE
See Also:
Constant Field Values

INCREMENT_PARAM

public static final String INCREMENT_PARAM
See Also:
Constant Field Values

DEFAULT_INCREMENT_SIZE

public static final int DEFAULT_INCREMENT_SIZE
See Also:
Constant Field Values

OPT_PARAM

public static final String OPT_PARAM
See Also:
Constant Field Values

FORCE_TBL_PARAM

public static final String FORCE_TBL_PARAM
See Also:
Constant Field Values

VALUE_COLUMN_PARAM

public static final String VALUE_COLUMN_PARAM
See Also:
Constant Field Values

DEF_VALUE_COLUMN

public static final String DEF_VALUE_COLUMN
See Also:
Constant Field Values
Constructor Detail

SequenceStyleGenerator

public SequenceStyleGenerator()
Method Detail

getDatabaseStructure

public DatabaseStructure getDatabaseStructure()

getOptimizer

public Optimizer getOptimizer()

getIdentifierType

public Type getIdentifierType()

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
Parameters:
params - param values, keyed by parameter name
Throws:
MappingException

generate

public Serializable generate(SessionImplementor session,
                             Object object)
                      throws HibernateException
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
Throws:
HibernateException

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

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 -
Returns:
String[]
Throws:
HibernateException

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 -
Returns:
String
Throws:
HibernateException