org.eclipse.persistence.sequencing

Class Sequence

java.lang.Object

org.eclipse.persistence.sequencing.Sequence

All Implemented Interfaces:

Serializable, Cloneable

Direct Known Subclasses:

DefaultSequence, StandardSequence, UUIDSequence

public abstract class Sequence
extends Object
implements Serializable, Cloneable

Purpose: Abstract class to define sequencing.

Description A sequence defines how generated ids are obtained. The main sequence types are TableSequence and NativeSequence. Descriptors using sequencing will use the sequence object defined in their session's DatabaseLogin with the name matching their sequence name. If a specific sequence is not defined for the name the DatabaseLogin's default sequence will be used.

See Also:

TableSequence, NativeSequence, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int	depth
protected int	initialValue
protected boolean	isCustomQualifier
protected String	name
protected org.eclipse.persistence.internal.databaseaccess.Platform	platform
protected String	qualifier
protected boolean	shouldAlwaysOverrideExistingValue
protected int	size

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
Object	clone()
static boolean	equalNameAndSize(Sequence seq1, Sequence seq2) INTERNAL: Used in equals.
boolean	equals(Object obj)
org.eclipse.persistence.internal.databaseaccess.Platform	getDatasourcePlatform()
Object	getGeneratedValue(org.eclipse.persistence.internal.databaseaccess.Accessor accessor, org.eclipse.persistence.internal.sessions.AbstractSession writeSession) INTERNAL: Return the newly-generated sequencing value.
abstract Object	getGeneratedValue(org.eclipse.persistence.internal.databaseaccess.Accessor accessor, org.eclipse.persistence.internal.sessions.AbstractSession writeSession, String seqName) INTERNAL: Return the newly-generated sequencing value.
Vector	getGeneratedVector(org.eclipse.persistence.internal.databaseaccess.Accessor accessor, org.eclipse.persistence.internal.sessions.AbstractSession writeSession) INTERNAL: Return a Vector of newly-generated sequencing values.
abstract Vector	getGeneratedVector(org.eclipse.persistence.internal.databaseaccess.Accessor accessor, org.eclipse.persistence.internal.sessions.AbstractSession writeSession, String seqName, int size) INTERNAL: Return a Vector of newly-generated sequencing values.
int	getInitialValue()
String	getName()
int	getPreallocationSize()
String	getQualified(String str) INTERNAL:
String	getQualifier() INTERNAL:
int	hashCode()
boolean	isConnected() PUBLIC: Indicates that Sequence is connected.
boolean	isCustomQualifier() INTERNAL:
boolean	isNative()
boolean	isTable()
boolean	isUnaryTable()
abstract void	onConnect() INTERNAL: This method is called when Sequencing object is created.
void	onConnect(org.eclipse.persistence.internal.databaseaccess.Platform platform) INTERNAL: This method is called when Sequencing object is created.
abstract void	onDisconnect() INTERNAL: This method is called when Sequencing object is destroyed.
void	onDisconnect(org.eclipse.persistence.internal.databaseaccess.Platform platform) INTERNAL: This method is called when Sequencing object is destroyed.
protected void	setDatasourcePlatform(org.eclipse.persistence.internal.databaseaccess.Platform platform)
void	setInitialValue(int initialValue)
void	setName(String name)
void	setPreallocationSize(int size)
void	setQualifier(String qualifier) INTERNAL:
void	setShouldAlwaysOverrideExistingValue(boolean shouldAlwaysOverrideExistingValue) ADVANCED: Set that to true if the sequence should always override the existing pk value.
abstract boolean	shouldAcquireValueAfterInsert() INTERNAL: Indicates whether sequencing value should be acquired after INSERT.
boolean	shouldAlwaysOverrideExistingValue() INTERNAL: Indicates whether the existing pk value should always be overridden by the sequence.
boolean	shouldAlwaysOverrideExistingValue(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.
abstract boolean	shouldUseTransaction() INTERNAL: Indicates whether TopLink should internally call beginTransaction() before getGeneratedValue/Vector, and commitTransaction after.
String	toString()
protected void	verifyPlatform(org.eclipse.persistence.internal.databaseaccess.Platform otherPlatform) INTERNAL: Make sure that the sequence is not used by more than one platform.

Methods inherited from class java.lang.Object

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

Field Detail

name

protected String name

size

protected int size

platform

protected org.eclipse.persistence.internal.databaseaccess.Platform platform

initialValue

protected int initialValue

depth

protected int depth

qualifier

protected String qualifier

isCustomQualifier

protected boolean isCustomQualifier

shouldAlwaysOverrideExistingValue

protected boolean shouldAlwaysOverrideExistingValue

Constructor Detail

Sequence

public Sequence()

Sequence

public Sequence(String name)

Create a new sequence with the name.

Sequence

public Sequence(String name,
                int size)

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

Sequence

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

Method Detail

isNative

public boolean isNative()

isTable

public boolean isTable()

isUnaryTable

public boolean isUnaryTable()

getName

public String getName()

setName

public void setName(String name)

getPreallocationSize

public int getPreallocationSize()

setPreallocationSize

public void setPreallocationSize(int size)

getInitialValue

public int getInitialValue()

setInitialValue

public void setInitialValue(int initialValue)

clone

public Object clone()

Overrides:

clone in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

equalNameAndSize

public static boolean equalNameAndSize(Sequence seq1,
                                       Sequence seq2)

INTERNAL: Used in equals.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

setDatasourcePlatform

protected void setDatasourcePlatform(org.eclipse.persistence.internal.databaseaccess.Platform platform)

getDatasourcePlatform

public org.eclipse.persistence.internal.databaseaccess.Platform getDatasourcePlatform()

shouldAcquireValueAfterInsert

public abstract 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.

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.

shouldUseTransaction

public abstract boolean shouldUseTransaction()

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.

getGeneratedValue

public abstract Object getGeneratedValue(org.eclipse.persistence.internal.databaseaccess.Accessor accessor,
                                         org.eclipse.persistence.internal.sessions.AbstractSession writeSession,
                                         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).

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

getGeneratedValue

public Object getGeneratedValue(org.eclipse.persistence.internal.databaseaccess.Accessor accessor,
                                org.eclipse.persistence.internal.sessions.AbstractSession writeSession)

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).

Parameters:

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

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

getGeneratedVector

public abstract Vector getGeneratedVector(org.eclipse.persistence.internal.databaseaccess.Accessor accessor,
                                          org.eclipse.persistence.internal.sessions.AbstractSession writeSession,
                                          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).

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).

getGeneratedVector

public Vector getGeneratedVector(org.eclipse.persistence.internal.databaseaccess.Accessor accessor,
                                 org.eclipse.persistence.internal.sessions.AbstractSession writeSession)

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).

Parameters:

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

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

onConnect

public void onConnect(org.eclipse.persistence.internal.databaseaccess.Platform platform)

INTERNAL: This method is called when Sequencing object is created. Don't override this method.

onConnect

public abstract void onConnect()

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

onDisconnect

public void onDisconnect(org.eclipse.persistence.internal.databaseaccess.Platform platform)

INTERNAL: This method is called when Sequencing object is destroyed. Don't override this method.

onDisconnect

public abstract void onDisconnect()

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

isConnected

public boolean isConnected()

PUBLIC: Indicates that Sequence is connected.

verifyPlatform

protected void verifyPlatform(org.eclipse.persistence.internal.databaseaccess.Platform otherPlatform)

INTERNAL: Make sure that the sequence is not used by more than one platform.

setQualifier

public void setQualifier(String qualifier)

INTERNAL:

isCustomQualifier

public boolean isCustomQualifier()

INTERNAL:

getQualifier

public String getQualifier()

INTERNAL:

getQualified

public String getQualified(String str)

INTERNAL:

setShouldAlwaysOverrideExistingValue

public void setShouldAlwaysOverrideExistingValue(boolean shouldAlwaysOverrideExistingValue)

ADVANCED: Set that to true if the sequence should always override the existing pk value.

shouldAlwaysOverrideExistingValue

public boolean shouldAlwaysOverrideExistingValue()

INTERNAL: Indicates whether the existing pk value should always be overridden by the sequence. As always the version of the method taking seqName is provided for the benefit of DefaultSequence.

shouldAlwaysOverrideExistingValue

public boolean shouldAlwaysOverrideExistingValue(String seqName)

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

toString

public String toString()

Overrides:

toString in class Object