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oracle.olapi.data.source
Class CursorSpecification

java.lang.Object
oracle.olapi.data.source.CursorSpecification

All Implemented Interfaces:

CursorInfoSpecification

Direct Known Subclasses:

CompoundCursorSpecification, ValueCursorSpecification

public abstract class CursorSpecification

extends java.lang.Object

implements CursorInfoSpecification

The base class for an object that specifies characteristics of a Cursor for a Source. A CursorSpecification implements the CursorInfoSpecification interface. An application creates a CursorSpecification with the createCursorInfoSpecification(Source rootSource) method of a DataProvider. That method returns a CompoundCursorSpecification or a ValueCursorSpecification.

After creating a CursorInfoSpecification, an application can create a CursorManager by passing the CursorInfoSpecification to a createCursorManager method of the DataProvider. The application can then create a Cursor by calling the createCursor method of the CursorManager.

With the methods of a CursorSpecification, an application can specify that it wants information such as the extent of the Cursor, which is the total number of elements the Cursor contains, or the position in a parent Cursor at which a child Cursor starts or ends. Calculating the extent or the starting or ending positions can take a lot of time and computing resources, so an application should only set the CursorSpecification to do so when it needs the information.

An application can also set the default fetch size for a Cursor by calling the setDefaultFetchSize method of the CursorSpecification for that Cursor. The fetch size is the number of elements that a Cursor retrieves during a single fetch from the data store. If the application sets the default fetch size on a CursorSpecification, then it can then change the fetch size for the Cursor by calling the setFetchSize method of the Cursor itself.

With other methods of a CursorSpecification, an application can accept a CursorSpecificationVisitor or retrieve the Source for the CursorSpecification. The Source for a CursorSpecification is the Source that defines the data that the Cursor retrieves from the data store.

Method Summary

abstract java.lang.Object	acceptVisitor(CursorSpecificationVisitor visitor, java.lang.Object context) Calls the visitCursorSpecification method of the specified CursorSpecificationVisitor and passes that method the CursorSpecification and the specified context object.
int	getDefaultFetchSize() Gets the fetch size set as the default for this CursorSpecification.
Source	getSource() Gets the Source associated with the CursorSpecification.
Transaction	getTransaction() Gets the Transaction object for this CursorSpecification.
boolean	isExtentCalculationSpecified() Indicates whether the CursorSpecification is set to calculate the extent for the Cursor.
boolean	isParentEndCalculationSpecified() Indicates whether the CursorSpecification is set to calculate the ending position of the Cursor in the parent Cursor.
boolean	isParentStartCalculationSpecified() Indicates whether the CursorSpecification is set to calculate the starting position of the Cursor in the parent Cursor.
void	setDefaultFetchSize(int defaultFetchSize) Specifies a default fetch size for the Cursor.
void	setExtentCalculationSpecified(boolean b) Specifies whether to calculate the extent of the Cursor.
void	setParentEndCalculationSpecified(boolean b) Specifies whether to calculate the ending position of the Cursor in the parent Cursor.
void	setParentStartCalculationSpecified(boolean b) Specifies whether to calculate the starting position of the Cursor in the parent Cursor.
void	setTransaction(Transaction transaction) Specifies the Transaction object for this CursorSpecification.

Methods inherited from class java.lang.Object

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

Method Detail

getTransaction

public final Transaction getTransaction()

Gets the Transaction object for this CursorSpecification.

Returns:

The Transaction object for this CursorSpecification.

setTransaction

public final void setTransaction(Transaction transaction)

Specifies the Transaction object for this CursorSpecification.

Parameters:

transaction - The Transaction object for this CursorSpecification.

acceptVisitor

public abstract java.lang.Object acceptVisitor(CursorSpecificationVisitor visitor,
                                               java.lang.Object context)

Calls the visitCursorSpecification method of the specified CursorSpecificationVisitor and passes that method the CursorSpecification and the specified context object.

Parameters:

visitor - A CursorSpecificationVisitor.

context - An Object.

Returns:

The Object returned by the visitCursorSpecification method.

getDefaultFetchSize

public final int getDefaultFetchSize()

Gets the fetch size set as the default for this CursorSpecification.

Returns:

The default fetch size for the CursorSpecification or Cursor.FETCH_SIZE_NOT_SPECIFIED if setting the default fetch size is not specified for this CursorSpecification.

getSource

public final Source getSource()

Gets the Source associated with the CursorSpecification.

Specified by:

getSource in interface CursorInfoSpecification

Returns:

The Source associated with the CursorSpecification.

isExtentCalculationSpecified

public final boolean isExtentCalculationSpecified()

Indicates whether the CursorSpecification is set to calculate the extent for the Cursor.

Returns:

true if the CursorSpecification is set to calculate the extent for the Cursor and false otherwise.

isParentEndCalculationSpecified

public final boolean isParentEndCalculationSpecified()

Indicates whether the CursorSpecification is set to calculate the ending position of the Cursor in the parent Cursor.

Specified by:

isParentEndCalculationSpecified in interface CursorInfoSpecification

Returns:

true if the CursorSpecification is set to calculate the ending position of the Cursor in the parent Cursor and false otherwise.

isParentStartCalculationSpecified

public final boolean isParentStartCalculationSpecified()

Indicates whether the CursorSpecification is set to calculate the starting position of the Cursor in the parent Cursor.

Specified by:

isParentStartCalculationSpecified in interface CursorInfoSpecification

Returns:

true if the CursorSpecification is set to calculate the starting position of the Cursor in the parent Cursor and false otherwise.

setDefaultFetchSize

public final void setDefaultFetchSize(int defaultFetchSize)
                               throws java.lang.IllegalArgumentException

Specifies a default fetch size for the Cursor. The default fetch size must be greater than zero. The fetch size can only be set at one level in the hierarchy of a parent Cursor and the children of that parent.

Parameters:

defaultFetchSize - The value to specify as the default fetch size.

Throws:

java.lang.IllegalArgumentException - Indicates that the values specified for the fetch size is zero or less than zero.

setExtentCalculationSpecified

public final void setExtentCalculationSpecified(boolean b)

Specifies whether to calculate the extent of the Cursor. For a CompoundCursorSpecification, calling this method causes Oracle OLAP to calculate the extents of all of the descendents of the CompoundCursorSpecification.

Parameters:

b - true to calculate the extent and false otherwise.

setParentEndCalculationSpecified

public final void setParentEndCalculationSpecified(boolean b)

Specifies whether to calculate the ending position of the Cursor in the parent Cursor.

Specified by:

setParentEndCalculationSpecified in interface CursorInfoSpecification

Parameters:

b - true to calculate the ending position of the Cursor in the parent and false otherwise.

setParentStartCalculationSpecified

public final void setParentStartCalculationSpecified(boolean b)

Specifies whether to calculate the starting position of the Cursor in the parent Cursor.

Specified by:

setParentStartCalculationSpecified in interface CursorInfoSpecification

Parameters:

b - true to calculate the starting position of the Cursor in the parent and false otherwise.

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