Package org.eclipse.persistence.queries

Class CursoredStreamPolicy

java.lang.Object

org.eclipse.persistence.internal.queries.ContainerPolicy

org.eclipse.persistence.queries.CursorPolicy

org.eclipse.persistence.queries.CursoredStreamPolicy

All Implemented Interfaces:

Serializable, Cloneable, CoreContainerPolicy<AbstractSession>

public class CursoredStreamPolicy
extends CursorPolicy

Purpose: Used to support cursored streams in a read query.

Responsibilities: Execute the cursored read and build the stream.

Since:

TOPLink/Java 1.2

Author:

James Sutherland

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected int	initialReadSize
protected ValueReadQuery	sizeQuery

Fields inherited from class org.eclipse.persistence.queries.CursorPolicy

pageSize, query

Fields inherited from class org.eclipse.persistence.internal.queries.ContainerPolicy

constructor, defaultContainerClass, elementDescriptor

Constructor Summary

Constructors

Constructor	Description
CursoredStreamPolicy()	default constructor
CursoredStreamPolicy(ReadQuery query, int pageSize)	set the initial read size to match the page size
CursoredStreamPolicy(ReadQuery query, int initialReadSize, int pageSize)
CursoredStreamPolicy(ReadQuery query, int initialReadSize, int pageSize, ValueReadQuery sizeQuery)

Method Summary

Modifier and Type	Method	Description
Object	execute()	INTERNAL: Execute the cursored select and build the stream.
int	getInitialReadSize()	Specifies the number of elements to be read initially into a cursored stream.
ValueReadQuery	getSizeQuery()	Return the query used to read the size.
boolean	hasSizeQuery()	INTERNAL: Return if a custom size query is defined.
boolean	isCursoredStreamPolicy()
void	prepare(DatabaseQuery query, AbstractSession session)	INTERNAL: Prepare and validate.
Object	remoteExecute()	INTERNAL: Execute the cursored select and build the stream.
void	setInitialReadSize(int initialReadSize)	Specifies the number of elements to be read initially into a cursored stream
void	setSizeQuery(ValueReadQuery sizeQuery)	Set the query used to read the size.

Methods inherited from class org.eclipse.persistence.queries.CursorPolicy

clone, createChangeEvent, getPageSize, getQuery, hasNext, isCursorPolicy, iteratorFor, next, overridesRead, setPageSize, setQuery, sizeFor, toStringInfo

Methods inherited from class org.eclipse.persistence.internal.queries.ContainerPolicy

addAdditionalFieldsToQuery, addAll, addAll, addFieldsForMapKey, addInto, addInto, addInto, addInto, addNestedJoinsQueriesForMapKey, addNextValueFromIteratorInto, buildChangeSetForNewObjectInCollection, buildCloneForKey, buildCollectionEntry, buildContainerFromVector, buildDefaultPolicy, buildKey, buildKeyFromJoinedRow, buildPolicyFor, buildPolicyFor, buildReferencesPKList, buildSelectionQueryForDirectCollectionMapping, cascadeDiscoverAndPersistUnregisteredNewObjects, cascadePerformRemoveIfRequired, cascadeRegisterNewIfRequired, clear, clone, cloneFor, collectObjectForNewCollection, compareCollectionsForChange, compareKeys, concatenateContainers, containerInstance, containerInstance, contains, contains, convertClassNamesToClasses, copyMapDataToRow, createChangeSetForKeys, createWrappedObjectFromExistingWrappedObject, deleteWrappedObject, equals, getAdditionalFieldsForJoin, getAdditionalTablesForJoinQuery, getChangeValuesFrom, getCloneDataFromChangeSet, getConstructor, getContainerClass, getContainerClassName, getDefaultContainerClass, getDescriptorForMapKey, getElementDescriptor, getIdentityFieldsForMapKey, getKeyMappingDataForWriteQuery, getKeySelectionCriteria, getKeyType, hasElementDescriptor, hashCode, hasOrder, initialize, initializeConstructor, isCollectionPolicy, isDirectMapPolicy, isEmpty, isListPolicy, isMapKeyObject, isMappedKeyMapPolicy, isMapPolicy, isOrderedListPolicy, isScrollableCursorPolicy, isValidContainer, isValidContainerType, iterateOnMapKey, keyFrom, keyFromEntry, keyFromIterator, mergeCascadeParts, mergeChanges, mergeChanges, next, nextEntry, nextEntry, postCalculateChanges, postCalculateChanges, postInitialize, prepareForExecution, processAdditionalWritableMapKeyFields, propagatesEventsToCollection, propogatePostDelete, propogatePostInsert, propogatePostUpdate, propogatePreDelete, propogatePreInsert, propogatePreUpdate, recordAddToCollectionInChangeRecord, recordPrivateOwnedRemovals, recordRemoveFromCollectionInChangeRecord, recordUpdateToCollectionInChangeRecord, removeFrom, removeFrom, removeFrom, requiresDataModificationEvents, setConstructor, setContainerClass, setContainerClassName, setDefaultContainerClass, setElementDescriptor, setKeyName, setKeyName, shouldAddAll, shouldIncludeKeyInDeleteEvent, shouldUpdateForeignKeysPostInsert, toString, unwrapElement, unwrapIteratorResult, updateChangeRecordForSelfMerge, updateJoinedMappingIndexesForMapKey, valueFromPKList, vectorFor

Methods inherited from class java.lang.Object

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

Field Detail

initialReadSize

protected int initialReadSize

sizeQuery

protected ValueReadQuery sizeQuery

Constructor Detail

CursoredStreamPolicy

public CursoredStreamPolicy()

default constructor

CursoredStreamPolicy

public CursoredStreamPolicy(ReadQuery query,
                            int pageSize)

set the initial read size to match the page size

CursoredStreamPolicy

public CursoredStreamPolicy(ReadQuery query,
                            int initialReadSize,
                            int pageSize)

CursoredStreamPolicy

public CursoredStreamPolicy(ReadQuery query,
                            int initialReadSize,
                            int pageSize,
                            ValueReadQuery sizeQuery)

Method Detail

execute

public Object execute()

INTERNAL: Execute the cursored select and build the stream.

Specified by:

execute in class CursorPolicy

getInitialReadSize

public int getInitialReadSize()

Specifies the number of elements to be read initially into a cursored stream.

getSizeQuery

public ValueReadQuery getSizeQuery()

Return the query used to read the size. This is required for SQL read queries.

hasSizeQuery

public boolean hasSizeQuery()

INTERNAL: Return if a custom size query is defined.

isCursoredStreamPolicy

public boolean isCursoredStreamPolicy()

Overrides:

isCursoredStreamPolicy in class ContainerPolicy

prepare

public void prepare(DatabaseQuery query,
                    AbstractSession session)
             throws QueryException

INTERNAL: Prepare and validate.

Overrides:

prepare in class CursorPolicy

Throws:

QueryException

remoteExecute

public Object remoteExecute()

INTERNAL: Execute the cursored select and build the stream.

Specified by:

remoteExecute in class CursorPolicy

setInitialReadSize

public void setInitialReadSize(int initialReadSize)

Specifies the number of elements to be read initially into a cursored stream

setSizeQuery

public void setSizeQuery(ValueReadQuery sizeQuery)

Set the query used to read the size. This is required for SQL read queries.