org.fastnate.generator.context

Class SequenceIdGenerator

java.lang.Object

org.fastnate.generator.context.IdGenerator

org.fastnate.generator.context.SequenceIdGenerator

public class SequenceIdGenerator
extends IdGenerator

Stores the current value for a SequenceGenerator.

Author:

Tobias Liefke

Constructor Summary

Constructors

Constructor and Description
SequenceIdGenerator(javax.persistence.SequenceGenerator generator, GeneratorDialect dialect, boolean relativeIds) Creates a new instance of SequenceIdGenerator.

Method Summary

Modifier and Type	Method and Description
void	addNextValue(InsertStatement statement, String column, Number value) Adds the generated value to the given statement.
List<? extends EntityStatement>	alignNextValue() Creates all statements that are necessary to set the next value created from the database is currentValue + 1.
long	createNextValue() Resolves the next value of this generator.
List<? extends EntityStatement>	createPreInsertStatements() Creates the statements that are needed in the output before IdGenerator.addNextValue(InsertStatement, String, Number).
long	getCurrentValue() The last value returned by IdGenerator.createNextValue(Class).
String	getExpression(String table, String column, Number targetId, boolean whereExpression) Builds the reference to another entity that has the given ID.
boolean	isPostIncrement() Indicates that IdGenerator.createNextValue(Class) should be called after the entity was written - as the value is not available before.

Methods inherited from class org.fastnate.generator.context.IdGenerator

createNextValue, derive

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceIdGenerator

public SequenceIdGenerator(javax.persistence.SequenceGenerator generator,
                           GeneratorDialect dialect,
                           boolean relativeIds)

Creates a new instance of SequenceIdGenerator.

Parameters:

generator - the annotation that contains our settings

dialect - the current database dialect

relativeIds - indicates that the sequence is always used, instead of absolute IDs

Method Detail

addNextValue

public void addNextValue(InsertStatement statement,
                         String column,
                         Number value)

Description copied from class: IdGenerator

Adds the generated value to the given statement. Depending on the generator this may add the value itself or a reference to the value.

Specified by:

addNextValue in class IdGenerator

Parameters:

statement - the current insert statement

column - the name of the ID column

value - the current value of the column, previously generated with IdGenerator.createNextValue()

alignNextValue

public List<? extends EntityStatement> alignNextValue()

Description copied from class: IdGenerator

Creates all statements that are necessary to set the next value created from the database is currentValue + 1.

Specified by:

alignNextValue in class IdGenerator

Returns:

the statements - an empty list if nothing is necessary

createNextValue

public long createNextValue()

Description copied from class: IdGenerator

Resolves the next value of this generator.

Specified by:

createNextValue in class IdGenerator

Returns:

the generated value

createPreInsertStatements

public List<? extends EntityStatement> createPreInsertStatements()

Description copied from class: IdGenerator

Creates the statements that are needed in the output before IdGenerator.addNextValue(InsertStatement, String, Number).

Specified by:

createPreInsertStatements in class IdGenerator

Returns:

statements that increase the sequence value before the insert statement

getCurrentValue

public long getCurrentValue()

Description copied from class: IdGenerator

The last value returned by IdGenerator.createNextValue(Class).

Specified by:

getCurrentValue in class IdGenerator

Returns:

the current value

getExpression

public String getExpression(String table,
                            String column,
                            Number targetId,
                            boolean whereExpression)

Description copied from class: IdGenerator

Builds the reference to another entity that has the given ID.

Specified by:

getExpression in class IdGenerator

Parameters:

table - the name of the table of the entity

column - the name of the column of the ID

targetId - the current value of the ID

whereExpression - indicates if this expression is needed for a "SELECT ... WHERE ..." - some dialects behave differently in this situation

Returns:

the expression for selecting the ID

isPostIncrement

public boolean isPostIncrement()

Description copied from class: IdGenerator

Indicates that IdGenerator.createNextValue(Class) should be called after the entity was written - as the value is not available before.

Specified by:

isPostIncrement in class IdGenerator

Returns:

true if the database increments the value _after_ the insert statement was executed, true if it is incremented before or during the execution