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TableGenerator (Hibernate API Documentation) - Hibernate 3.2.4 正式版 API 英文文档


org.hibernate.id.enhanced
Class TableGenerator

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

public class TableGenerator
extends TransactionHelper
implements PersistentIdentifierGenerator, Configurable

A "segmented" version of the enhanced table generator. The term "segmented" refers to the fact that this table can hold multiple value generators, segmented by a key.

Configuration parameters:
NAME DEFAULT DESCRIPTION
TABLE_PARAM DEF_TABLE The name of the table to use to store/retrieve values
VALUE_COLUMN_PARAM DEF_VALUE_COLUMN The name of column which holds the sequence value for the given segment
SEGMENT_COLUMN_PARAM DEF_SEGMENT_COLUMN The name of the column which holds the segment key
SEGMENT_VALUE_PARAM DEF_SEGMENT_VALUE The value indicating which segment is used by this generator; refers to values in the SEGMENT_COLUMN_PARAM column
SEGMENT_LENGTH_PARAM DEF_SEGMENT_LENGTH The data length of the SEGMENT_COLUMN_PARAM column; used for schema creation
INITIAL_PARAM DEFAULT_INITIAL_VALUE The initial value to be stored for the given segment
INCREMENT_PARAM DEFAULT_INCREMENT_SIZE The increment size for the underlying segment; see the discussion on Optimizer for more details.
OPT_PARAM depends on defined increment size Allows explicit definition of which optimization strategy to use

Author:
Steve Ebersole

Field Summary
static String DEF_SEGMENT_COLUMN
           
static int DEF_SEGMENT_LENGTH
           
static String DEF_SEGMENT_VALUE
           
static String DEF_TABLE
           
static String DEF_VALUE_COLUMN
           
static int DEFAULT_INCREMENT_SIZE
           
static int DEFAULT_INITIAL_VALUE
           
static String INCREMENT_PARAM
           
static String INITIAL_PARAM
           
static String OPT_PARAM
           
static String SEGMENT_COLUMN_PARAM
           
static String SEGMENT_LENGTH_PARAM
           
static String SEGMENT_VALUE_PARAM
           
static String TABLE_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
TableGenerator()
           
 
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 doWorkInCurrentTransaction(Connection conn, String sql)
          The work to be done
 Serializable generate(SessionImplementor session, Object obj)
          Generate a new identifier.
 Object generatorKey()
          Return a key unique to the underlying database objects.
 Type getIdentifierType()
           
 int getIncrementSize()
           
 int getInitialValue()
           
 Optimizer getOptimizer()
           
 String getSegmentColumnName()
           
 String getSegmentValue()
           
 int getSegmentValueLength()
           
 long getTableAccessCount()
           
 String getTableName()
           
 String getValueColumnName()
           
 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 Detail

TABLE_PARAM

public static final String TABLE_PARAM
See Also:
Constant Field Values

DEF_TABLE

public static final String DEF_TABLE
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

SEGMENT_COLUMN_PARAM

public static final String SEGMENT_COLUMN_PARAM
See Also:
Constant Field Values

DEF_SEGMENT_COLUMN

public static final String DEF_SEGMENT_COLUMN
See Also:
Constant Field Values

SEGMENT_VALUE_PARAM

public static final String SEGMENT_VALUE_PARAM
See Also:
Constant Field Values

DEF_SEGMENT_VALUE

public static final String DEF_SEGMENT_VALUE
See Also:
Constant Field Values

SEGMENT_LENGTH_PARAM

public static final String SEGMENT_LENGTH_PARAM
See Also:
Constant Field Values

DEF_SEGMENT_LENGTH

public static final int DEF_SEGMENT_LENGTH
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
Constructor Detail

TableGenerator

public TableGenerator()
Method Detail

getTableName

public String getTableName()

getSegmentColumnName

public String getSegmentColumnName()

getSegmentValue

public String getSegmentValue()

getSegmentValueLength

public int getSegmentValueLength()

getValueColumnName

public String getValueColumnName()

getIdentifierType

public Type getIdentifierType()

getInitialValue

public int getInitialValue()

getIncrementSize

public int getIncrementSize()

getOptimizer

public Optimizer getOptimizer()

getTableAccessCount

public long getTableAccessCount()

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 obj)
Description copied from interface: IdentifierGenerator
Generate a new identifier.

Specified by:
generate in interface IdentifierGenerator
Parameters:
session -
obj - the entity or toplevel collection for which the id is being generated
Returns:
a new identifier

doWorkInCurrentTransaction

public Serializable doWorkInCurrentTransaction(Connection conn,
                                               String sql)
                                        throws SQLException
Description copied from class: TransactionHelper
The work to be done

Specified by:
doWorkInCurrentTransaction in class TransactionHelper
Throws:
SQLException

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

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