oracle.toplink.essentials.sequencing

Class StandardSequence

java.lang.Object

oracle.toplink.essentials.sequencing.Sequence

oracle.toplink.essentials.sequencing.StandardSequence

All Implemented Interfaces:

Serializable, Cloneable

Direct Known Subclasses:

QuerySequence

public abstract class StandardSequence
extends Sequence

Purpose: An abstract class providing default sequence behavior.

See Also:

Serialized Form

Field Summary

Fields inherited from class oracle.toplink.essentials.sequencing.Sequence

depth, initialValue, name, platform, size

Constructor Summary

Constructors

Constructor and Description
StandardSequence()
StandardSequence(String name)
StandardSequence(String name, int size)
StandardSequence(String name, int size, int initialValue)

Method Summary

Modifier and Type	Method and Description
protected Vector	createVector(Number sequence, String seqName, int size) INTERNAL: given sequence = 10, size = 5 will create Vector (6,7,8,9,10)
Object	getGeneratedValue(Accessor accessor, AbstractSession writeSession, String seqName) INTERNAL: Return the newly-generated sequencing value.
Vector	getGeneratedVector(Accessor accessor, AbstractSession writeSession, String seqName, int size) INTERNAL: Return a Vector of newly-generated sequencing values.
void	onConnect() INTERNAL: This method is called when Sequencing object is created.
void	onDisconnect() INTERNAL: This method is called when Sequencing object is destroyed.
abstract boolean	shouldAcquireValueAfterInsert() INTERNAL: Indicates whether sequencing value should be acquired after INSERT.
boolean	shouldOverrideExistingValue(String seqName, Object existingValue) INTERNAL: Indicates whether existing attribute value should be overridden.
abstract boolean	shouldUseTransaction() INTERNAL: Indicates whether TopLink should internally call beginTransaction() before getGeneratedValue/Vector, and commitTransaction after.
protected abstract Number	updateAndSelectSequence(Accessor accessor, AbstractSession writeSession, String seqName, int size)

Methods inherited from class oracle.toplink.essentials.sequencing.Sequence

clone, equalNameAndSize, equals, getDatasourcePlatform, getGeneratedValue, getGeneratedVector, getInitialValue, getName, getPreallocationSize, isConnected, onConnect, onDisconnect, setDatasourcePlatform, setInitialValue, setName, setPreallocationSize, shouldOverrideExistingValue, shouldUsePreallocation, verifyPlatform

Methods inherited from class java.lang.Object

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

Constructor Detail

StandardSequence

public StandardSequence()

StandardSequence

public StandardSequence(String name)

StandardSequence

public StandardSequence(String name,
                        int size)

StandardSequence

public StandardSequence(String name,
                        int size,
                        int initialValue)

Method Detail

onConnect

public void onConnect()

Description copied from class: Sequence

INTERNAL: This method is called when Sequencing object is created. If it requires initialization, subclass should override this method.

Specified by:

onConnect in class Sequence

onDisconnect

public void onDisconnect()

Description copied from class: Sequence

INTERNAL: This method is called when Sequencing object is destroyed. If it requires deinitialization, subclass should override this method.

Specified by:

onDisconnect in class Sequence

updateAndSelectSequence

protected abstract Number updateAndSelectSequence(Accessor accessor,
                                                  AbstractSession writeSession,
                                                  String seqName,
                                                  int size)

shouldAcquireValueAfterInsert

public abstract boolean shouldAcquireValueAfterInsert()

Description copied from class: Sequence

INTERNAL: Indicates whether sequencing value should be acquired after INSERT. Note that preallocation could be used only in case sequencing values should be acquired before insert (this method returns false). In default implementation, it is true for table sequencing and native sequencing on Oracle platform, false for native sequencing on other platforms.

Specified by:

shouldAcquireValueAfterInsert in class Sequence

shouldUseTransaction

public abstract boolean shouldUseTransaction()

Description copied from class: Sequence

INTERNAL: Indicates whether TopLink should internally call beginTransaction() before getGeneratedValue/Vector, and commitTransaction after. In default implementation, it is true for table sequencing and false for native sequencing.

Specified by:

shouldUseTransaction in class Sequence

getGeneratedValue

public Object getGeneratedValue(Accessor accessor,
                                AbstractSession writeSession,
                                String seqName)

Description copied from class: Sequence

INTERNAL: Return the newly-generated sequencing value. Used only in case preallocation is not used (shouldUsePreallocation()==false). Accessor may be non-null only in case shouldUseSeparateConnection()==true. Even in this case accessor could be null - if SequencingControl().shouldUseSeparateConnection()==false; Therefore in case shouldUseSeparateConnection()==true, implementation should handle both cases: use a separate connection if provided (accessor != null), or get by without it (accessor == null).

Specified by:

getGeneratedValue in class Sequence

Parameters:

accessor - Accessor is a separate sequencing accessor (may be null);

writeSession - Session is a Session used for writing (either ClientSession or DatabaseSession);

seqName - String is sequencing number field name

getGeneratedVector

public Vector getGeneratedVector(Accessor accessor,
                                 AbstractSession writeSession,
                                 String seqName,
                                 int size)

Description copied from class: Sequence

INTERNAL: Return a Vector of newly-generated sequencing values. Used only in case preallocation is used (shouldUsePreallocation()==true). Accessor may be non-null only in case shouldUseSeparateConnection()==true. Even in this case accessor could be null - if SequencingControl().shouldUseSeparateConnection()==false; Therefore in case shouldUseSeparateConnection()==true, implementation should handle both cases: use a separate connection if provided (accessor != null), or get by without it (accessor == null).

Specified by:

getGeneratedVector in class Sequence

Parameters:

accessor - Accessor is a separate sequencing accessor (may be null);

writeSession - Session is a Session used for writing (either ClientSession or DatabaseSession);

seqName - String is sequencing number field name

size - int number of values to preallocate (output Vector size).

shouldOverrideExistingValue

public boolean shouldOverrideExistingValue(String seqName,
                                           Object existingValue)

INTERNAL: Indicates whether existing attribute value should be overridden. This method is called in case an attribute mapped to PK of sequencing-using descriptor contains non-null value. Default implementation is: Always override for "after insert" sequencing, override non-positive Numbers for "before insert" sequencing.

Specified by:

shouldOverrideExistingValue in class Sequence

Parameters:

seqName - String is sequencing number field name

existingValue - Object is a non-null value of PK-mapped attribute.

createVector

protected Vector createVector(Number sequence,
                              String seqName,
                              int size)

INTERNAL: given sequence = 10, size = 5 will create Vector (6,7,8,9,10)

Parameters:

seqName - String is sequencing number field name

existingValue - Object is a non-null value of PK-mapped attribute.

size - int size of Vector to create.