org.eclipse.persistence.sequencing

Class DefaultSequence

java.lang.Object

org.eclipse.persistence.sequencing.Sequence

org.eclipse.persistence.sequencing.DefaultSequence

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

public class DefaultSequence
extends Sequence

Purpose: Reference to the default sequence.

Description This sequence can be used to provide a sequence using the session's default sequencing mechanism but override the pre-allocation size.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.eclipse.persistence.sequencing.Sequence

depth, initialValue, isCustomQualifier, name, platform, qualifier, shouldAlwaysOverrideExistingValue, size

Constructor Summary

Constructors

Constructor and Description
DefaultSequence()
DefaultSequence(java.lang.String name) Create a new sequence with the name.
DefaultSequence(java.lang.String name, int size) Create a new sequence with the name and sequence pre-allocation size.
DefaultSequence(java.lang.String name, int size, int initialValue)

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object obj)
Sequence	getDefaultSequence() INTERNAL: Return the platform's default sequence.
java.lang.Object	getGeneratedValue(org.eclipse.persistence.internal.databaseaccess.Accessor accessor, org.eclipse.persistence.internal.sessions.AbstractSession writeSession, java.lang.String seqName) INTERNAL: Return the newly-generated sequencing value.
java.util.Vector	getGeneratedVector(org.eclipse.persistence.internal.databaseaccess.Accessor accessor, org.eclipse.persistence.internal.sessions.AbstractSession writeSession, java.lang.String seqName, int size) INTERNAL: Return a Vector of newly-generated sequencing values.
int	getInitialValue()
int	getPreallocationSize()
int	hashCode()
boolean	hasPreallocationSize()
boolean	isConnected() PUBLIC: Indicates that Sequence is connected.
void	onConnect() INTERNAL: This method is called when Sequencing object is created.
void	onDisconnect() INTERNAL: This method is called when Sequencing object is destroyed..
void	setQualifier(java.lang.String qualifier) INTERNAL: Ignored, getDefaultSequence().getQualifier() used instead.
boolean	shouldAcquireValueAfterInsert() INTERNAL: Indicates whether sequencing value should be acquired after INSERT.
boolean	shouldAlwaysOverrideExistingValue(java.lang.String seqName) INTERNAL: Indicates whether the existing pk value should always be overridden by the sequence.
boolean	shouldUsePreallocation() INTERNAL: Indicates whether several sequencing values should be acquired at a time and be kept by TopLink.
boolean	shouldUseTransaction() INTERNAL: Indicates whether EclipseLink should internally call beginTransaction() before getGeneratedValue/Vector, and commitTransaction after.

Methods inherited from class org.eclipse.persistence.sequencing.Sequence

clone, equalNameAndSize, getDatasourcePlatform, getGeneratedValue, getGeneratedVector, getName, getQualified, getQualifier, isCustomQualifier, isNative, isTable, isUnaryTable, onConnect, onDisconnect, setDatasourcePlatform, setInitialValue, setName, setPreallocationSize, setShouldAlwaysOverrideExistingValue, shouldAlwaysOverrideExistingValue, toString, verifyPlatform

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DefaultSequence

public DefaultSequence()

DefaultSequence

public DefaultSequence(java.lang.String name)

Create a new sequence with the name.

DefaultSequence

public DefaultSequence(java.lang.String name,
                       int size)

Create a new sequence with the name and sequence pre-allocation size.

DefaultSequence

public DefaultSequence(java.lang.String name,
                       int size,
                       int initialValue)

Method Detail

getDefaultSequence

public Sequence getDefaultSequence()

INTERNAL: Return the platform's default sequence.

hasPreallocationSize

public boolean hasPreallocationSize()

getPreallocationSize

public int getPreallocationSize()

Overrides:

getPreallocationSize in class Sequence

getInitialValue

public int getInitialValue()

Overrides:

getInitialValue in class Sequence

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class Sequence

hashCode

public int hashCode()

Overrides:

hashCode in class Sequence

shouldAcquireValueAfterInsert

public boolean shouldAcquireValueAfterInsert()

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

shouldAlwaysOverrideExistingValue

public boolean shouldAlwaysOverrideExistingValue(java.lang.String seqName)

INTERNAL: Indicates whether the existing pk value should always be overridden by the sequence.

Overrides:

shouldAlwaysOverrideExistingValue in class Sequence

shouldUsePreallocation

public boolean shouldUsePreallocation()

INTERNAL: Indicates whether several sequencing values should be acquired at a time and be kept by TopLink. This in only possible in case sequencing numbers should be acquired before insert (shouldAcquireValueAfterInsert()==false). In default implementation, it is true for table sequencing and native sequencing on Oracle platform, false for native sequencing on other platforms.

Overrides:

shouldUsePreallocation in class Sequence

shouldUseTransaction

public boolean shouldUseTransaction()

INTERNAL: Indicates whether EclipseLink 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 java.lang.Object getGeneratedValue(org.eclipse.persistence.internal.databaseaccess.Accessor accessor,
                                          org.eclipse.persistence.internal.sessions.AbstractSession writeSession,
                                          java.lang.String seqName)

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 java.util.Vector getGeneratedVector(org.eclipse.persistence.internal.databaseaccess.Accessor accessor,
                                           org.eclipse.persistence.internal.sessions.AbstractSession writeSession,
                                           java.lang.String seqName,
                                           int size)

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).

onConnect

public void onConnect()

INTERNAL: This method is called when Sequencing object is created. It's a chance to do initialization.

Specified by:

onConnect in class Sequence

onDisconnect

public void onDisconnect()

INTERNAL: This method is called when Sequencing object is destroyed.. It's a chance to do deinitialization.

Specified by:

onDisconnect in class Sequence

isConnected

public boolean isConnected()

PUBLIC: Indicates that Sequence is connected.

Overrides:

isConnected in class Sequence

setQualifier

public void setQualifier(java.lang.String qualifier)

INTERNAL: Ignored, getDefaultSequence().getQualifier() used instead.

Overrides:

setQualifier in class Sequence