EclipseLink Core 4.0.2 · org.eclipse.persistence.internal.indirection.DatabaseValueHolder

Modifier and Type	Field and Description
protected boolean	isCoordinatedWithProperty The variable below is used as part of the implementation of WeavedAttributeValueHolderInterface It is used to track whether a valueholder that has been weaved into a class is coordinated with the underlying property Set internally in EclipseLink when the state of coordination between a weaved valueholder and the underlying property is known
protected volatile boolean	isInstantiated Indicates whether the object has been read from the database or not.
protected AbstractRecord	row Stores the row representation of the object.
protected transient AbstractSession	session Stores the session for the database that contains the object.
protected volatile T	value Stores the object after it is read from the database.

Access	Constructor and Description
protected	DatabaseValueHolder() Default constructor.

Method Summary

Modifier and Type	Method and Description
public Object	clone() Overrides java.lang.Object.clone. Implements org.eclipse.persistence.indirection.ValueHolderInterface.clone. PUBLIC: Copy the value holder (but not its' reference, shallow).
public AbstractRecord	getRow() Return the row.
public AbstractSession	getSession() Return the session.
public T	getValue() Implements org.eclipse.persistence.indirection.ValueHolderInterface.getValue. Return the object.
public T	getValue(UnitOfWorkImpl uow) Process against the UOW and attempt to load a local copy before going to the shared cache If null is returned then the calling UOW will instantiate as normal.
public ValueHolderInterface<?>	getWrappedValueHolder()
protected abstract T	instantiate() Instantiate the object.
public abstract T	instantiateForUnitOfWorkValueHolder(UnitOfWorkValueHolder<T> unitOfWorkValueHolder) Triggers UnitOfWork valueholders directly without triggering the wrapped valueholder (this).
public boolean	isCoordinatedWithProperty() Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.isCoordinatedWithProperty. This method is used as part of the implementation of WeavedAttributeValueHolderInterface It is used to check whether a valueholder that has been weaved into a class is coordinated with the underlying property
public boolean	Returns: true if getValue() won't trigger a database read. isEasilyInstantiated() INTERNAL: Answers if this valueholder is easy to instantiate.
public boolean	isInstantiated() Implements org.eclipse.persistence.indirection.ValueHolderInterface.isInstantiated. Return a boolean indicating whether the object has been read from the database or not.
public boolean	isNewlyWeavedValueHolder() Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.isNewlyWeavedValueHolder. This method is used as part of the implementation of WeavedAttributeValueHolderInterface.
public abstract boolean	isPessimisticLockingValueHolder() Answers if this valueholder is a pessimistic locking one.
public boolean	isSerializedRemoteUnitOfWorkValueHolder() Used to determine if this is a remote uow value holder that was serialized to the server.
protected boolean	isTransactionalValueHolder() Answers if this valueholder is referenced only by a UnitOfWork valueholder.
public void	postInstantiate() INTERNAL: Run any extra code required after the valueholder instantiates
public void	privilegedSetValue(T value) Set the object.
public void	releaseWrappedValueHolder(AbstractSession targetSession) Releases a wrapped valueholder privately owned by a particular unit of work.
protected void	resetFields() Reset all the fields that are not needed after instantiation.
public void	setInstantiated() Set the instantiated flag to true.
public void	setIsCoordinatedWithProperty(boolean coordinated) Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.setIsCoordinatedWithProperty. This method is used as part of the implementation of WeavedAttributeValueHolderInterface It is used internally by EclipseLink to set whether a valueholder that has been weaved into a class is coordinated with the underlying property
public void	setIsNewlyWeavedValueHolder(boolean isNew) Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.setIsNewlyWeavedValueHolder. This method is used as part of the implementation of WeavedAttributeValueHolderInterface A DatabaseValueHolder is set up by EclipseLink and will never be a newly weaved valueholder As a result, this method is stubbed out.
public void	setRow(AbstractRecord row) Set the row.
public void	setSession(AbstractSession session) Set the session.
public void	setUninstantiated() Set the instantiated flag to false.
public void	setValue(T value) Implements org.eclipse.persistence.indirection.ValueHolderInterface.setValue. Set the object.
public boolean	shouldAllowInstantiationDeferral() Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.shouldAllowInstantiationDeferral. INTERNAL: Return if add/remove should trigger instantiation or avoid.
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.

Inherited from java.lang.Object:: equals finalize getClass hashCode notify notifyAll wait wait wait

isCoordinatedWithProperty	back to summary
protected boolean isCoordinatedWithProperty The variable below is used as part of the implementation of WeavedAttributeValueHolderInterface It is used to track whether a valueholder that has been weaved into a class is coordinated with the underlying property Set internally in EclipseLink when the state of coordination between a weaved valueholder and the underlying property is known

isInstantiated	back to summary
protected volatile boolean isInstantiated Indicates whether the object has been read from the database or not.

row	back to summary
protected AbstractRecord row Stores the row representation of the object.

session	back to summary
protected transient AbstractSession session Stores the session for the database that contains the object.

value	back to summary
protected volatile T value Stores the object after it is read from the database.

DatabaseValueHolder	back to summary
protected DatabaseValueHolder() Default constructor.

Method Detail

clone	back to summary
public Object clone() Overrides java.lang.Object.clone. Implements org.eclipse.persistence.indirection.ValueHolderInterface.clone. Doc from org.eclipse.persistence.indirection.ValueHolderInterface.clone. PUBLIC: Copy the value holder (but not its' reference, shallow). Returns:Object Doc from java.lang.Object.clone. a clone of this instance. Annotations @Override

clone

back to summary

public Object clone()

Overrides java.lang.Object.clone.

Implements org.eclipse.persistence.indirection.ValueHolderInterface.clone.

Doc from org.eclipse.persistence.indirection.ValueHolderInterface.clone.

PUBLIC: Copy the value holder (but not its' reference, shallow).

Returns:Object

Doc from java.lang.Object.clone.

a clone of this instance.

Annotations

@Override

getRow	back to summary
public AbstractRecord getRow() Return the row.

getSession	back to summary
public AbstractSession getSession() Return the session.

getValue	back to summary
public T getValue() Implements org.eclipse.persistence.indirection.ValueHolderInterface.getValue. Return the object. Annotations @Override

getValue

back to summary

public T getValue()

Implements org.eclipse.persistence.indirection.ValueHolderInterface.getValue.

Return the object.

Annotations

@Override

getValue	back to summary
public T getValue(UnitOfWorkImpl uow) Process against the UOW and attempt to load a local copy before going to the shared cache If null is returned then the calling UOW will instantiate as normal.

getWrappedValueHolder	back to summary
public ValueHolderInterface<?> getWrappedValueHolder()

instantiate	back to summary
protected abstract T instantiate() throws DatabaseException Instantiate the object.

instantiateForUnitOfWorkValueHolder	back to summary
public abstract T instantiateForUnitOfWorkValueHolder(UnitOfWorkValueHolder<T> unitOfWorkValueHolder) Triggers UnitOfWork valueholders directly without triggering the wrapped valueholder (this). When in transaction and/or for pessimistic locking the UnitOfWorkValueHolder needs to be triggered directly without triggering the wrapped valueholder. However only the wrapped valueholder knows how to trigger the indirection, i.e. it may be a batchValueHolder, and it stores all the info like the row and the query. Note Implementations of this method are not necessarily thread-safe. They must be used in a synchronized manner

instantiateForUnitOfWorkValueHolder

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public abstract T instantiateForUnitOfWorkValueHolder(UnitOfWorkValueHolder<T> unitOfWorkValueHolder)

Triggers UnitOfWork valueholders directly without triggering the wrapped valueholder (this).

When in transaction and/or for pessimistic locking the UnitOfWorkValueHolder needs to be triggered directly without triggering the wrapped valueholder. However only the wrapped valueholder knows how to trigger the indirection, i.e. it may be a batchValueHolder, and it stores all the info like the row and the query.

Note

Implementations of this method are not necessarily thread-safe. They must be used in a synchronized manner

isCoordinatedWithProperty	back to summary
public boolean isCoordinatedWithProperty() Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.isCoordinatedWithProperty. This method is used as part of the implementation of WeavedAttributeValueHolderInterface It is used to check whether a valueholder that has been weaved into a class is coordinated with the underlying property Annotations @Override

isCoordinatedWithProperty

back to summary

public boolean isCoordinatedWithProperty()

Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.isCoordinatedWithProperty.

This method is used as part of the implementation of WeavedAttributeValueHolderInterface It is used to check whether a valueholder that has been weaved into a class is coordinated with the underlying property

Annotations

@Override

isEasilyInstantiated	back to summary
public boolean isEasilyInstantiated() INTERNAL: Answers if this valueholder is easy to instantiate. Returns:boolean true if getValue() won't trigger a database read.

isEasilyInstantiated

back to summary

public boolean isEasilyInstantiated()

INTERNAL: Answers if this valueholder is easy to instantiate.

Returns:boolean: true if getValue() won't trigger a database read.

isInstantiated	back to summary
public boolean isInstantiated() Implements org.eclipse.persistence.indirection.ValueHolderInterface.isInstantiated. Return a boolean indicating whether the object has been read from the database or not. Annotations @Override

isInstantiated

back to summary

public boolean isInstantiated()

Implements org.eclipse.persistence.indirection.ValueHolderInterface.isInstantiated.

Return a boolean indicating whether the object has been read from the database or not.

Annotations

@Override

isNewlyWeavedValueHolder	back to summary
public boolean isNewlyWeavedValueHolder() Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.isNewlyWeavedValueHolder. This method is used as part of the implementation of WeavedAttributeValueHolderInterface. A DatabaseValueHolder is set up by TopLink and will never be a newly weaved valueholder. As a result, this method is stubbed out. Annotations @Override

isNewlyWeavedValueHolder

back to summary

public boolean isNewlyWeavedValueHolder()

Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.isNewlyWeavedValueHolder.

This method is used as part of the implementation of WeavedAttributeValueHolderInterface. A DatabaseValueHolder is set up by TopLink and will never be a newly weaved valueholder. As a result, this method is stubbed out.

Annotations

@Override

isPessimisticLockingValueHolder	back to summary
public abstract boolean isPessimisticLockingValueHolder() Answers if this valueholder is a pessimistic locking one. Such valueholders are special in that they can be triggered multiple times by different UnitsOfWork. Each time a lock query will be issued. Hence even if instantiated it may have to be instantiated again, and once instantiated all fields can not be reset. Note Implementations of this method are not necessarily thread-safe. They must be used in a synchronizaed manner

isPessimisticLockingValueHolder

back to summary

public abstract boolean isPessimisticLockingValueHolder()

Answers if this valueholder is a pessimistic locking one. Such valueholders are special in that they can be triggered multiple times by different UnitsOfWork. Each time a lock query will be issued. Hence even if instantiated it may have to be instantiated again, and once instantiated all fields can not be reset.

Note

Implementations of this method are not necessarily thread-safe. They must be used in a synchronizaed manner

isSerializedRemoteUnitOfWorkValueHolder	back to summary
public boolean isSerializedRemoteUnitOfWorkValueHolder() Used to determine if this is a remote uow value holder that was serialized to the server. It has no reference to its wrapper value holder, so must find its original object to be able to instantiate.

isTransactionalValueHolder	back to summary
protected boolean isTransactionalValueHolder() Answers if this valueholder is referenced only by a UnitOfWork valueholder. I.e. it was built in valueFromRow which was called by buildCloneFromRow. Sometimes in transaction a UnitOfWork clone, and all valueholders, are built directly from the row; however a UnitOfWorkValueHolder does not know how to instantiate itself so wraps this which does. On a successful merge must be released to the session cache with releaseWrappedValueHolder.

isTransactionalValueHolder

back to summary

protected boolean isTransactionalValueHolder()

Answers if this valueholder is referenced only by a UnitOfWork valueholder. I.e. it was built in valueFromRow which was called by buildCloneFromRow.

Sometimes in transaction a UnitOfWork clone, and all valueholders, are built directly from the row; however a UnitOfWorkValueHolder does not know how to instantiate itself so wraps this which does.

On a successful merge must be released to the session cache with releaseWrappedValueHolder.

postInstantiate back to summary

postInstantiate	back to summary
public void postInstantiate() INTERNAL: Run any extra code required after the valueholder instantiates See Also `QueryBasedValueHolder`

public void postInstantiate()

INTERNAL: Run any extra code required after the valueholder instantiates

See Also: QueryBasedValueHolder

privilegedSetValue	back to summary
public void privilegedSetValue(T value) Set the object. This is used only by the privileged methods. One must be very careful in using this method.

releaseWrappedValueHolder	back to summary
public void releaseWrappedValueHolder(AbstractSession targetSession) Releases a wrapped valueholder privately owned by a particular unit of work. When unit of work clones are built directly from rows no object in the shared cache points to this valueholder, so it can store the unit of work as its session. However once that UnitOfWork commits and the valueholder is merged into the shared cache, the session needs to be reset to the root session, ie. the server session.

releaseWrappedValueHolder

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public void releaseWrappedValueHolder(AbstractSession targetSession)

Releases a wrapped valueholder privately owned by a particular unit of work.

When unit of work clones are built directly from rows no object in the shared cache points to this valueholder, so it can store the unit of work as its session. However once that UnitOfWork commits and the valueholder is merged into the shared cache, the session needs to be reset to the root session, ie. the server session.

resetFields	back to summary
protected void resetFields() Reset all the fields that are not needed after instantiation.

setInstantiated	back to summary
public void setInstantiated() Set the instantiated flag to true.

setIsCoordinatedWithProperty	back to summary
public void setIsCoordinatedWithProperty(boolean coordinated) Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.setIsCoordinatedWithProperty. This method is used as part of the implementation of WeavedAttributeValueHolderInterface It is used internally by EclipseLink to set whether a valueholder that has been weaved into a class is coordinated with the underlying property Annotations @Override

setIsCoordinatedWithProperty

back to summary

public void setIsCoordinatedWithProperty(boolean coordinated)

Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.setIsCoordinatedWithProperty.

This method is used as part of the implementation of WeavedAttributeValueHolderInterface It is used internally by EclipseLink to set whether a valueholder that has been weaved into a class is coordinated with the underlying property

Annotations

@Override

setIsNewlyWeavedValueHolder	back to summary
public void setIsNewlyWeavedValueHolder(boolean isNew) Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.setIsNewlyWeavedValueHolder. This method is used as part of the implementation of WeavedAttributeValueHolderInterface A DatabaseValueHolder is set up by EclipseLink and will never be a newly weaved valueholder As a result, this method is stubbed out. Annotations @Override

setIsNewlyWeavedValueHolder

back to summary

public void setIsNewlyWeavedValueHolder(boolean isNew)

Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.setIsNewlyWeavedValueHolder.

This method is used as part of the implementation of WeavedAttributeValueHolderInterface A DatabaseValueHolder is set up by EclipseLink and will never be a newly weaved valueholder As a result, this method is stubbed out.

Annotations

@Override

setRow	back to summary
public void setRow(AbstractRecord row) Set the row.

setSession	back to summary
public void setSession(AbstractSession session) Set the session.

setUninstantiated	back to summary
public void setUninstantiated() Set the instantiated flag to false.

setValue	back to summary
public void setValue(T value) Implements org.eclipse.persistence.indirection.ValueHolderInterface.setValue. Set the object. Annotations @Override

setValue

back to summary

public void setValue(T value)

Implements org.eclipse.persistence.indirection.ValueHolderInterface.setValue.

Set the object.

Annotations

@Override

shouldAllowInstantiationDeferral	back to summary
public boolean shouldAllowInstantiationDeferral() Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.shouldAllowInstantiationDeferral. INTERNAL: Return if add/remove should trigger instantiation or avoid. Current instantiation is avoided is using change tracking. Annotations @Override

shouldAllowInstantiationDeferral

back to summary

public boolean shouldAllowInstantiationDeferral()

Implements org.eclipse.persistence.indirection.WeavedAttributeValueHolderInterface.shouldAllowInstantiationDeferral.

INTERNAL: Return if add/remove should trigger instantiation or avoid. Current instantiation is avoided is using change tracking.

Annotations

@Override

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Doc from java.lang.Object.toString. Returns a string representation of the object. Returns:String a string representation of the object. Annotations @Override

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object.

Returns:String

a string representation of the object.

Annotations