/*******************************************************************************
* Copyright (c) 1998, 2010 Oracle. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.internal.queries;
import java.util.*;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.io.Serializable;
import java.lang.reflect.Constructor;
import org.eclipse.persistence.internal.descriptors.DescriptorIterator;
import org.eclipse.persistence.internal.expressions.SQLSelectStatement;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.helper.DatabaseTable;
import org.eclipse.persistence.internal.helper.Helper;
import org.eclipse.persistence.internal.helper.ClassConstants;
import org.eclipse.persistence.internal.sessions.CollectionChangeRecord;
import org.eclipse.persistence.internal.sessions.MergeManager;
import org.eclipse.persistence.internal.sessions.ObjectChangeSet;
import org.eclipse.persistence.internal.sessions.UnitOfWorkChangeSet;
import org.eclipse.persistence.queries.*;
import org.eclipse.persistence.exceptions.*;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
import org.eclipse.persistence.internal.security.PrivilegedNewInstanceFromClass;
import org.eclipse.persistence.internal.security.PrivilegedInvokeConstructor;
import org.eclipse.persistence.internal.security.PrivilegedGetConstructorFor;
import org.eclipse.persistence.internal.sessions.UnitOfWorkImpl;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.descriptors.CMPPolicy;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.descriptors.changetracking.CollectionChangeEvent;
import org.eclipse.persistence.indirection.IndirectCollection;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.mappings.CollectionMapping;
import org.eclipse.persistence.mappings.DatabaseMapping;
/**
* <p><b>Purpose</b>:
* Used to support collections in read queries.
* <p>
* <p><b>Responsibilities</b>:
* Map the results into the appropriate collection instance.
* Generically support special collections like cursored stream and virtual collection.
*
* @author James Sutherland
* @since TOPLink/Java 1.2
*/
public abstract class ContainerPolicy implements Cloneable, Serializable {
private static final long serialVersionUID = 6971791021041582975L;
/**
* Allow the default collection class to be set.
*/
protected static Class defaultContainerClass = ClassConstants.Vector_class;
/** The descriptor is used to wrap and unwrap objects using the wrapper policy. **/
protected transient ClassDescriptor elementDescriptor;
protected transient Constructor constructor;
/**
* ADVANCED:
* Return the default collection class.
*/
public static Class getDefaultContainerClass() {
return defaultContainerClass;
}
/**
* ADVANCED:
* Allow the default collection class to be set.
*/
public static void setDefaultContainerClass(Class collectionClass) {
defaultContainerClass = collectionClass;
}
/**
* Default constructor.
*/
public ContainerPolicy() {
}
/**
* INTERNAL:
* Called when the selection query is being initialized to add any required additional fields to the
* query. By default, there are not additional fields required but this method is overridden by subclasses.
*
* @see MappedKeyMapContinerPolicy
*/
public void addAdditionalFieldsToQuery(ReadQuery selectionQuery, Expression baseExpression){
}
/**
* INTERNAL:
* Called when the insert query is being initialized to ensure the fields for the key are in the insert query
*
* @see MappedKeyMapContainerPolicy
*/
public void addFieldsForMapKey(AbstractRecord joinRow){
}
/**
* INTERNAL:
* Add element to container.
* This is used to add to a collection independent of JDK 1.1 and 1.2.
* The session may be required to wrap for the wrapper policy.
* Return whether the container changed
*/
public boolean addInto(Object element, Object container, AbstractSession session) {
return addInto(null, element, container, session);
}
/**
* INTERNAL:
* Add element to container.
* This is used to add to a collection independent of type.
* The session may be required to wrap for the wrapper policy.
* The row may be required by subclasses, such as MappedKeyMap.
* Return whether the container changed.
*/
public boolean addInto(Object element, Object container, AbstractSession session, AbstractRecord dbRow, ObjectBuildingQuery query) {
return addInto(null, element, container, session);
}
/**
* INTERNAL:
* This is used for ordered List containers to add all of the elements
* to the collection in the order of the index field in the row.
* This is currently only used by OrderListContainerPolicy, so this is just a stub.
* The passing of the query is to allow future compatibility with Maps (ordered Map).
*/
public boolean addAll(List elements, Object container, AbstractSession session, List<AbstractRecord> dbRows, ObjectBuildingQuery query) {
boolean changed = false;
for(int i=0; i < elements.size(); i++) {
changed |= addInto(elements.get(i), container, session, dbRows.get(i), query);
}
return changed;
}
/**
* INTERNAL:
* This is used for adding to a direct map or direct collection from the database.
* The row data may also be requires, as in the case of indexed ordered lists,
* or direct maps.
*/
public boolean addInto(Object element, Object container, AbstractSession session, AbstractRecord row, DataReadQuery query) {
return addInto(null, element, container, session);
}
/**
* INTERNAL:
* This is used for ordered List containers to add all of the elements
* to the collection in the order of the index field in the row.
* This is currently only used by OrderListContainerPolicy, so this is just a stub.
* The passing of the query is to allow future compatibility with Maps (ordered Map).
*/
public boolean addAll(List elements, Object container, AbstractSession session, List<AbstractRecord> rows, DataReadQuery query) {
boolean changed = false;
for(int i=0; i < elements.size(); i++) {
changed |= addInto(elements.get(i), container, session, rows.get(i), query);
}
return changed;
}
/**
* INTERNAL:
* Add element to container.
* This is used to add to a collection independent of type.
* The session may be required to wrap for the wrapper policy.
* Return whether the container changed.
*/
public boolean addInto(Object key, Object element, Object container, AbstractSession session) {
throw QueryException.cannotAddToContainer(element, container, this);
}
/**
* INTERNAL:
* Used for joining. Add any queries necessary for joining to the join manager
* This method will be overridden by subclasses that handle map keys
*/
public void addNestedJoinsQueriesForMapKey(JoinedAttributeManager joinManager, ObjectLevelReadQuery query, AbstractSession session){
}
/**
* INTERNAL:
* This method is used to add the next value from an iterator built using ContainerPolicy's iteratorFor() method
* into the toCollection.
* This method is overridden by subclasses to provide extended functionality for map keys
*
* @see MappedKeyMapContainerPolicy
*
* @param valuesIterator
* @param toCollection
* @param mapping
* @param unitOfWork
* @param isExisting
*/
public void addNextValueFromIteratorInto(Object valuesIterator, Object parent, Object toCollection, CollectionMapping mapping, UnitOfWorkImpl unitOfWork, boolean isExisting){
Object cloneValue = mapping.buildElementClone(next(valuesIterator, unitOfWork), parent, unitOfWork, isExisting);
// add the object to the uow list of private owned objects if it is a candidate and the
// uow should discover new objects
if (!isExisting && mapping.isCandidateForPrivateOwnedRemoval() && unitOfWork.shouldDiscoverNewObjects() && cloneValue != null && unitOfWork.isObjectNew(cloneValue)) {
unitOfWork.addPrivateOwnedObject(mapping, cloneValue);
}
addInto(cloneValue, toCollection, unitOfWork);
}
/**
* Build a clone for the key of a Map represented by this container policy if necessary.
* By default, the key is not cloned since in standard EclipseLink Mappings it will not be
* an Entity
* @param key
* @param uow
* @param isExisting
* @return
*/
public Object buildCloneForKey(Object key, Object parent, UnitOfWorkImpl uow, boolean isExisting){
return key;
}
/**
* INTERNAL:
* Return an object representing an entry in the collection represented by this container policy
* This method will be overridden to allow MapContainerPolicy to return a construct that
* contains the key and the value
*
* @see MappedKeyMapContainerPolicy
* @param objectAdded
* @param changeSet
* @return
*/
public Object buildCollectionEntry(Object objectAdded, ObjectChangeSet changeSet){
return objectAdded;
}
/**
* INTERNAL:
* Return a container populated with the contents of the specified Vector.
*/
public Object buildContainerFromVector(Vector vector, AbstractSession session) {
Object container = containerInstance(vector.size());
int size = vector.size();
for (int index = 0; index < size; index++) {
addInto(vector.get(index), container, session);
}
return container;
}
/**
* Extract the key for the map from the provided row
* overridden by subclasses that deal with map keys
* @param row
* @param query
* @param session
* @return
*/
public Object buildKey(AbstractRecord row, ObjectBuildingQuery query, AbstractSession session){
return null;
}
/**
* INTERNAL:
* This method will access the target relationship and create a list of information to rebuild the collection.
* This method is used in combination with the CachedValueHolder to store references to PK's to be loaded
* from a cache instead of a query.
* @see ContainerPolicy.buildReferencesPKList()
* @see MappedKeyMapContainerPolicy.buildReferencesPKList()
*/
public Object[] buildReferencesPKList(Object container, AbstractSession session){
Object[] result = new Object[this.sizeFor(container)];
Iterator iterator = (Iterator)this.iteratorFor(container);
int index = 0;
while(iterator.hasNext()){
Object target = iterator.next();
if (target != null){
CMPPolicy policy = elementDescriptor.getCMPPolicy();
if (policy != null && policy.isCMP3Policy()){
result[index] = policy.createPrimaryKeyInstance(target, session);
}else{
result[index] = elementDescriptor.getObjectBuilder().extractPrimaryKeyFromObject(target, session);
}
++index;
}
}
return result;
}
/**
* Extract the key for the map from the provided row
* overridden by subclasses that deal with map keys
* @param row
* @param query
* @param session
* @return
*/
public Object buildKeyFromJoinedRow(AbstractRecord row, JoinedAttributeManager joinManager, ObjectBuildingQuery query, AbstractSession session){
return null;
}
/**
* INTERNAL:
* Return the appropriate container policy for the default container class.
*/
public static ContainerPolicy buildDefaultPolicy() {
return buildPolicyFor(ContainerPolicy.getDefaultContainerClass());
}
/**
* INTERNAL:
* Return the appropriate container policy for the specified
* concrete container class.
*/
public static ContainerPolicy buildPolicyFor(Class concreteContainerClass) {
return buildPolicyFor(concreteContainerClass, false);
}
/**
* INTERNAL:
* Return the appropriate container policy for the specified
* concrete container class.
*/
public static ContainerPolicy buildPolicyFor(Class concreteContainerClass, boolean hasOrdering) {
if (Helper.classImplementsInterface(concreteContainerClass, ClassConstants.List_Class)) {
if (hasOrdering) {
return new OrderedListContainerPolicy(concreteContainerClass);
} else if (concreteContainerClass == ClassConstants.Vector_class) {
return new VectorContainerPolicy(concreteContainerClass);
} else if (concreteContainerClass == ClassConstants.IndirectList_Class) {
return new IndirectListContainerPolicy(concreteContainerClass);
} else if (concreteContainerClass == ClassConstants.ArrayList_class) {
return new ArrayListContainerPolicy(concreteContainerClass);
} else {
return new ListContainerPolicy(concreteContainerClass);
}
} else if (Helper.classImplementsInterface(concreteContainerClass, ClassConstants.SortedSet_Class)) {
return new SortedCollectionContainerPolicy(concreteContainerClass);
} else if (Helper.classImplementsInterface(concreteContainerClass, ClassConstants.Collection_Class)) {
return new CollectionContainerPolicy(concreteContainerClass);
} else if (Helper.classImplementsInterface(concreteContainerClass, ClassConstants.Map_Class)) {
return new MapContainerPolicy(concreteContainerClass);
} else if (concreteContainerClass.equals(ClassConstants.CursoredStream_Class)) {
return new CursoredStreamPolicy();
} else if (concreteContainerClass.equals(ClassConstants.ScrollableCursor_Class)) {
return new ScrollableCursorPolicy();
}
throw ValidationException.illegalContainerClass(concreteContainerClass);
}
/**
* INTERNAL:
* This
* Certain key mappings favor different types of selection query. Return the appropriate
* type of selectionQuery
* @return
*/
public ReadQuery buildSelectionQueryForDirectCollectionMapping(){
DirectReadQuery query = new DirectReadQuery();
query.setSQLStatement(new SQLSelectStatement());
query.setContainerPolicy(this);
return query;
}
/**
* INTERNAL:
* Remove all the elements from the specified container.
* Valid only for certain subclasses.
*/
public void clear(Object container) {
throw QueryException.methodNotValid(this, "clear(Object container)");
}
/**
* INTERNAL:
* Creates a CollectionChangeEvent for the container
*/
public abstract CollectionChangeEvent createChangeEvent(Object collectionOwner, String propertyName, Object collectionChanged, Object elementChanged, int changeType, Integer index);
/**
* INTERNAL:
* Return if the policy is equal to the other.
* By default if they are the same class, they are considered equal.
* This is used for query parse caching.
*/
@Override
public boolean equals(Object object) {
return (object != null) && (getClass().equals(object.getClass()));
}
/**
* INTERNAL:
* Cascade DiscoverAndPersistUnregisteredNewObjects to any mappings managed by the container policy. Be default, this is a no-op, but
* will be overridden by subclasses
*/
public void cascadeDiscoverAndPersistUnregisteredNewObjects(Object object, Map newObjects, Map unregisteredExistingObjects, Map visitedObjects, UnitOfWorkImpl uow) {
}
/**
* INTERNAL:
* Cascade performRemove to any mappings managed by the container policy. Be default, this is a no-op, but
* will be overridden by subclasses
*/
public void cascadePerformRemoveIfRequired(Object object, UnitOfWorkImpl uow, Map visitedObjects) {
}
/**
* INTERNAL:
* Cascade registerNew to any mappings managed by the container policy. Be default, this is a no-op, but
* will be overridden by subclasses
*/
public void cascadeRegisterNewIfRequired(Object object, UnitOfWorkImpl uow, Map visitedObjects) {
}
@Override
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
throw new InternalError();
}
}
public ContainerPolicy clone(ReadQuery query) {
return (ContainerPolicy)clone();
}
/**
* INTERNAL:
* Return a clone of the specified container. Can only be called for select subclasses.
*/
public Object cloneFor(Object container) {
throw QueryException.cannotCreateClone(this, container);
}
/**
* INTERNAL:
* Create change sets that contain map keys.
* This method will be overridden by subclasses that handle map keys
* @param originalKeyValues
* @param changeRecord
* @param session
* @param referenceDescriptor
*/
protected void createChangeSetForKeys(Map originalKeyValues, CollectionChangeRecord changeRecord, AbstractSession session, ClassDescriptor referenceDescriptor){
}
/**
* INTERNAL:
* Iterate over the list of new objects and create change sets for them
* This method is overridden by subclasses to handle map keys
* @param originalKeyValues
* @param cloneKeyValues
* @param newCollection
* @param changeRecord
* @param session
* @param referenceDescriptor
*/
protected void collectObjectForNewCollection(Map originalKeyValues, Map cloneKeyValues, Object newCollection, CollectionChangeRecord changeRecord, AbstractSession session, ClassDescriptor referenceDescriptor){
Object cloneIter = iteratorFor(newCollection);
while (hasNext(cloneIter)) {
Object wrappedFirstObject = nextEntry(cloneIter, session);
Object firstObject = unwrapIteratorResult(wrappedFirstObject);
// CR2378 null check to prevent a null pointer exception - XC
// If value is null then nothing can be done with it.
if (firstObject != null) {
Object key = firstObject;
if (changeRecord.getMapping().isAggregateCollectionMapping()){
key = referenceDescriptor.getObjectBuilder().extractPrimaryKeyFromObject(firstObject, session);
}
if (originalKeyValues.containsKey(key)) {
// There is an original in the cache
if ((compareKeys(firstObject, session))) {
// The keys have not changed
originalKeyValues.remove(key);
} else {
// The keys have changed, create a changeSet
// (it will be reused later) and set the old key
// value to be used to remove.
Object backUpVersion = null;
// CR4172 compare the keys from the back up to the
// clone not from the original to the clone.
if (((UnitOfWorkImpl)session).isClassReadOnly(firstObject.getClass())) {
backUpVersion = firstObject;
} else {
backUpVersion = ((UnitOfWorkImpl)session).getBackupClone(firstObject, referenceDescriptor);
}
ObjectChangeSet changeSet = referenceDescriptor.getObjectBuilder().createObjectChangeSet(firstObject, (UnitOfWorkChangeSet) changeRecord.getOwner().getUOWChangeSet(), session);
changeSet.setOldKey(keyFrom(backUpVersion, session));
changeSet.setNewKey(keyFrom(firstObject, session));
cloneKeyValues.put(key, firstObject);
}
} else {
// Place it in the add collection
buildChangeSetForNewObjectInCollection(wrappedFirstObject, referenceDescriptor, (UnitOfWorkChangeSet) changeRecord.getOwner().getUOWChangeSet(), session);
cloneKeyValues.put(key, firstObject);
}
}
}
}
/**
* INTERNAL:
* This method is used to calculate the differences between two collections.
*/
public void compareCollectionsForChange(Object oldCollection, Object newCollection, CollectionChangeRecord changeRecord, AbstractSession session, ClassDescriptor referenceDescriptor) {
// 2612538 - the default size of Map (32) is appropriate
Map originalKeyValues = null;
Map cloneKeyValues = null;
if (changeRecord.getMapping().isAggregateCollectionMapping()){
originalKeyValues = new HashMap();
cloneKeyValues = new HashMap();
}else{
originalKeyValues = new IdentityHashMap();
cloneKeyValues = new IdentityHashMap();
}
// Collect the values from the oldCollection.
if (oldCollection != null) {
Object backUpIter = iteratorFor(oldCollection);
while (hasNext(backUpIter)) {
Object wrappedSecondObject = nextEntry(backUpIter, session);
Object secondObject = unwrapIteratorResult(wrappedSecondObject);
// CR2378 null check to prevent a null pointer exception - XC
if (secondObject != null) {
Object key = secondObject;
if (changeRecord.getMapping().isAggregateCollectionMapping()){
key = referenceDescriptor.getObjectBuilder().extractPrimaryKeyFromObject(secondObject, session);
}
originalKeyValues.put(key, wrappedSecondObject);
}
}
}
if (newCollection != null){
collectObjectForNewCollection(originalKeyValues, cloneKeyValues, newCollection, changeRecord, session, referenceDescriptor);
}
createChangeSetForKeys(originalKeyValues, changeRecord, session, referenceDescriptor);
changeRecord.addAdditionChange(cloneKeyValues, this, (UnitOfWorkChangeSet) changeRecord.getOwner().getUOWChangeSet(), session);
changeRecord.addRemoveChange(originalKeyValues, this, (UnitOfWorkChangeSet) changeRecord.getOwner().getUOWChangeSet(), session);
}
public void buildChangeSetForNewObjectInCollection(Object object, ClassDescriptor referenceDescriptor, UnitOfWorkChangeSet uowChangeSet, AbstractSession session){
}
/**
* INTERNAL:
* Return true if keys are the same in the source as the backup. False otherwise
* in the case of readonly compare against the original
* For non map container policies return true always, because these policies have no concepts of Keys
*/
public boolean compareKeys(Object sourceKey, AbstractSession session) {
return true;
}
/**
* INTERNAL:
* Build a new container, add the contents of each of the specified containers
* to it, and return it.
* Both of the containers must use the same container policy (namely, this one).
*/
public Object concatenateContainers(Object firstContainer, Object secondContainer, AbstractSession session) {
Object container = containerInstance(sizeFor(firstContainer) + sizeFor(secondContainer));
for (Object firstIter = iteratorFor(firstContainer); hasNext(firstIter);) {
addInto(null, next(firstIter), container, session);
}
for (Object secondIter = iteratorFor(secondContainer); hasNext(secondIter);) {
addInto(null, next(secondIter), container, session);
}
return container;
}
/**
* INTERNAL:
* Return an instance of the container class.
* Null should never be returned.
* A ValidationException is thrown on error.
*/
public Object containerInstance() {
try {
if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){
try {
return AccessController.doPrivileged(new PrivilegedNewInstanceFromClass(getContainerClass()));
} catch (PrivilegedActionException exception) {
throw QueryException.couldNotInstantiateContainerClass(getContainerClass(), exception.getException());
}
} else {
return PrivilegedAccessHelper.newInstanceFromClass(getContainerClass());
}
} catch (Exception ex) {
throw QueryException.couldNotInstantiateContainerClass(getContainerClass(), ex);
}
}
/**
* INTERNAL:
* Return an instance of the container class with the specified initial capacity.
* Null should never be returned.
* A ValidationException is thrown on error.
*/
public Object containerInstance(int initialCapacity) {
if (getConstructor() == null) {
return containerInstance();
}
try {
Object[] arguments = new Object[1];
//Code change for 3732. No longer need to add 1 as this was for JDK 1.1
arguments[0] = Integer.valueOf(initialCapacity);
if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){
try {
return AccessController.doPrivileged(new PrivilegedInvokeConstructor(getConstructor(), arguments));
} catch (PrivilegedActionException exception) {
throw QueryException.couldNotInstantiateContainerClass(getContainerClass(), exception.getException());
}
} else {
return PrivilegedAccessHelper.invokeConstructor(getConstructor(), arguments);
}
} catch (Exception ex) {
throw QueryException.couldNotInstantiateContainerClass(getContainerClass(), ex);
}
}
/**
* INTERNAL:
* Return whether element exists in container.
*/
protected boolean contains(Object element, Object container) {
throw QueryException.methodNotValid(this, "contains(Object element, Object container)");
}
/**
* INTERNAL:
* Check if the object is contained in the collection.
* This is used to check contains in a collection independent of JDK 1.1 and 1.2.
* The session may be required to unwrap for the wrapper policy.
*/
public boolean contains(Object element, Object container, AbstractSession session) {
if (hasElementDescriptor() && getElementDescriptor().hasWrapperPolicy()) {
// The wrapper for the object must be removed.
Object iterator = iteratorFor(container);
while (hasNext(iterator)) {
Object next = next(iterator);
if (getElementDescriptor().getObjectBuilder().unwrapObject(next, session).equals(element)) {
return true;
}
}
return false;
} else {
return contains(element, container);
}
}
/**
* INTERNAL:
* Convert all the class-name-based settings in this ContainerPolicy to actual class-based
* settings
* This method is implemented by subclasses as necessary.
* @param classLoader
*/
public void convertClassNamesToClasses(ClassLoader classLoader){};
/**
* INTERNAL:
* This method will actually potentially wrap an object in two ways. It will first wrap the object
* based on the referenceDescriptor's wrapper policy. It will also potentially do some wrapping based
* on what is required by the container policy.
*
* @see MappedKeyMapContainerPolicy
* @param wrappedObject
* @param parent if this is an aggregate, the owner of the aggregate
* @param referenceDescriptor
* @param mergeManager
* @return
*/
public Object createWrappedObjectFromExistingWrappedObject(Object wrappedObject, Object parent, ClassDescriptor referenceDescriptor, MergeManager mergeManager){
return referenceDescriptor.getObjectBuilder().wrapObject(mergeManager.getTargetVersionOfSourceObject(unwrapIteratorResult(wrappedObject)), mergeManager.getSession());
}
/**
* INTERNAL:
* Delete the passed object
* This may be overridden by subclasses to deal with composite objects
*
* @see MappedKeyMapContainerPolicy
* @param objectDeleted
* @param session
*/
public void deleteWrappedObject(Object objectDeleted, AbstractSession session){
session.deleteObject(objectDeleted);
}
/**
* INTERNAL:
* This can be used by collection such as cursored stream to gain control over execution.
*/
public Object execute() {
throw QueryException.methodNotValid(this, "execute()");
}
/**
* INTERNAL:
* Return any tables that will be required when this mapping is used as part of a join query.
*/
public List<DatabaseTable> getAdditionalTablesForJoinQuery(){
return null;
}
/**
* INTERNAL:
* Return any additional fields required by the policy for a fetch join.
* This method will be overridden by ContainerPolicies that handle map keys.
*/
public List<DatabaseField> getAdditionalFieldsForJoin(CollectionMapping baseMapping) {
return null;
}
/**
* INTERNAL:
* Used to create an iterator on a the Map object passed to CollectionChangeRecord.addRemoveChange()
* to access the values to be removed. In the case of some container policies the values will actually
* be the keys.
*/
public Iterator getChangeValuesFrom(Map map){
return map.values().iterator();
}
/**
* INTERNAL:
* Used when objects are added or removed during an update.
* This method returns either the clone from the ChangeSet or a packaged
* version of it that contains things like map keys.
*/
public Object getCloneDataFromChangeSet(ObjectChangeSet changeSet){
return changeSet.getUnitOfWorkClone();
}
/**
* INTERNAL:
* Return the size constructor if available.
*/
protected Constructor getConstructor() {
return constructor;
}
/**
* INTERNAL:
* Return the class used for the container.
*/
public Class getContainerClass() {
throw QueryException.methodNotValid(this, "getContainerClass()");
}
/**
* INTERNAL:
* Used by the MW
*/
public String getContainerClassName() {
throw QueryException.methodNotValid(this, "getContainerClassName()");
}
/**
* INTERNAL:
* Return the reference descriptor for the map key if it exists
*/
public ClassDescriptor getDescriptorForMapKey(){
return null;
}
/**
* INTERNAL:
* Used for wrapping and unwrapping with the wrapper policy.
*/
public ClassDescriptor getElementDescriptor() {
return elementDescriptor;
}
/**
* INTERNAL:
* Return the fields that make up the identity of the key if this mapping is a list
* This method will be overridden by subclasses.
*/
public List<DatabaseField> getIdentityFieldsForMapKey(){
return null;
}
/**
* INTERNAL:
* Add any non-Foreign-key data from an Object describe by a MapKeyMapping to a database row
* This is typically used in write queries to ensure all the data stored in the collection table is included
* in the query.
*/
public Map getKeyMappingDataForWriteQuery(Object object, AbstractSession session){
return null;
}
/**
* INTERNAL:
* Get the selection criteria for the map key
* This will be overridden by container policies that allow maps
*/
public Expression getKeySelectionCriteria(){
return null;
}
/**
* INTERNAL:
* Return the type of the map key, this will be overridden by container policies that allow maps.
*/
public Object getKeyType(){
return null;
}
/**
* INTERNAL:
* Used for wrapping and unwrapping with the wrapper policy.
*/
public boolean hasElementDescriptor() {
return elementDescriptor != null;
}
/**
* INTERNAL:
* Return whether the iterator has more objects.
* The iterator is the one returned from #iteratorFor().
* Valid for some subclasses only.
*
* @see ContainerPolicy#iteratorFor(java.lang.Object)
*/
public abstract boolean hasNext(Object iterator);
/**
* INTERNAL:
* Returns true if the collection has order
*/
public boolean hasOrder() {
return false;
}
/**
* INTERNAL:
* Provide a hook to allow initialization of Container Policy parts
*/
public void initialize(AbstractSession session, DatabaseTable keyTable){
}
/**
* INTERNAL:
* Find the size constructor.
* Providing a size is important for performance.
*/
public void initializeConstructor() {
try {
Constructor constructor = null;
if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){
try {
constructor = (Constructor)AccessController.doPrivileged(new PrivilegedGetConstructorFor(getContainerClass(), new Class[] { ClassConstants.PINT }, false));
} catch (PrivilegedActionException exception) {
// If there is no constructor then the default will be used.
return;
}
} else {
constructor = PrivilegedAccessHelper.getConstructorFor(getContainerClass(), new Class[] { ClassConstants.PINT }, false);
}
setConstructor(constructor);
} catch (Exception exception) {
// If there is no constructor then the default will be used.
return;
}
}
public boolean isCollectionPolicy() {
return false;
}
public boolean isCursoredStreamPolicy() {
return false;
}
public boolean isScrollableCursorPolicy() {
return false;
}
public boolean isCursorPolicy() {
return false;
}
public boolean isDirectMapPolicy() {
return false;
}
/**
* INTERNAL:
* Return whether the container is empty.
*/
public boolean isEmpty(Object container) {
return sizeFor(container) == 0;
}
public boolean isListPolicy() {
return false;
}
public boolean isOrderedListPolicy() {
return false;
}
public boolean isMapPolicy() {
return false;
}
public boolean isMappedKeyMapPolicy(){
return false;
}
/**
* INTERNAL:
* Return if the map key this container policy represents is a OneToOne.
*/
public boolean isMapKeyObject() {
return false;
}
/**
* INTERNAL:
* Return whether the specified object is of a valid container type.
*
* @see org.eclipse.persistence.internal.queries.CollectionContainerPolicy#isValidContainer(Object)
* @see org.eclipse.persistence.internal.queries.MapContainerPolicy#isValidContainer(Object)
*/
public boolean isValidContainer(Object container) {
throw QueryException.methodNotValid(this, "isValidContainer(Object container)");
}
/**
* INTERNAL:
* Return whether the specified type is a valid container type.
*/
public boolean isValidContainerType(Class containerType) {
throw QueryException.methodNotValid(this, "isValidContainerType(Class containerType)");
}
/**
* INTERNAL:
* Used in Descriptor Iteration to iterate on map keys.
* This method is a no-op here, but will be overridden by subclasses
*/
public void iterateOnMapKey(DescriptorIterator iterator, Object element) {
}
/**
* INTERNAL:
* Return an iterator for the given container.
* This iterator can then be used as a parameter to #hasNext()
* and #next().
*
* @see ContainerPolicy#hasNext(java.lang.Object)
* @see ContainerPolicy#next(java.lang.Object)
*/
public abstract Object iteratorFor(Object container);
/**
* INTERNAL:
* Return the key for the specified element..
*/
public Object keyFrom(Object element, AbstractSession session) {
return null;
}
/**
* Get the key from the passed in Map.Entry
* This method will be overridden by ContainerPolicies that allows maps.
*/
public Object keyFromEntry(Object entry){
return null;
}
public Object keyFromIterator(Object iterator){
return null;
}
/**
* INTERNAL:
* Merge changes from the source to the target object. Because this is a
* collection mapping, values are added to or removed from the collection
* based on the change set.
*/
public Object mergeCascadeParts(ObjectChangeSet objectChanges, MergeManager mergeManager, AbstractSession parentSession) {
Object object = null;
if (mergeManager.shouldMergeChangesIntoDistributedCache()) {
// CR 2855 - Try to find the object first we may have merged it already.
object = objectChanges.getTargetVersionOfSourceObject(parentSession);
if ((object == null) && (objectChanges.isNew() || objectChanges.isAggregate()) && objectChanges.containsChangesFromSynchronization()) {
if (!mergeManager.getObjectsAlreadyMerged().containsKey(objectChanges)) {
// CR 2855 - If we haven't merged this object already then
// build a new object otherwise leave it as null which will
// stop the recursion.
// CR 3424 - Need to build the right instance based on
// class type instead of referenceDescriptor.
Class objectClass = objectChanges.getClassType(mergeManager.getSession());
object = mergeManager.getSession().getDescriptor(objectClass).getObjectBuilder().buildNewInstance();
// Store the change set to prevent us from creating this new object again.
mergeManager.getObjectsAlreadyMerged().put(objectChanges, object);
} else {
// CR 4012 - We have all ready created the object, must be
// in a cyclic merge on a new object so get it out of the
// already merged collection
object = mergeManager.getObjectsAlreadyMerged().get(objectChanges);
}
} else {
object = objectChanges.getTargetVersionOfSourceObject(parentSession, true);
}
if (objectChanges.containsChangesFromSynchronization()) {
mergeManager.mergeChanges(object, objectChanges);
}
} else {
mergeManager.mergeChanges(objectChanges.getUnitOfWorkClone(), objectChanges);
}
return object;
}
/**
* INTERNAL:
* Merge changes from the source to the target object. Because this is a
* collection mapping, values are added to or removed from the collection
* based on the change set.
*/
public void mergeChanges(CollectionChangeRecord changeRecord, Object valueOfTarget, boolean shouldMergeCascadeParts, MergeManager mergeManager, AbstractSession parentSession) {
ObjectChangeSet objectChanges;
// Step 1 - iterate over the removed changes and remove them from the container.
Iterator removeObjects = changeRecord.getRemoveObjectList().keySet().iterator();
// Ensure the collection is synchronized while changes are being made,
// clone also synchronizes on collection (does not have cache key read-lock for indirection).
// Must synchronize of the real collection as the clone does so.
Object synchronizedValueOfTarget = valueOfTarget;
if (valueOfTarget instanceof IndirectCollection) {
synchronizedValueOfTarget = ((IndirectCollection)valueOfTarget).getDelegateObject();
}
synchronized (synchronizedValueOfTarget) {
while (removeObjects.hasNext()) {
objectChanges = (ObjectChangeSet) removeObjects.next();
removeFrom(objectChanges.getOldKey(), objectChanges.getTargetVersionOfSourceObject(mergeManager.getSession()), valueOfTarget, parentSession);
if (!mergeManager.shouldMergeChangesIntoDistributedCache()) {
mergeManager.registerRemovedNewObjectIfRequired(objectChanges.getUnitOfWorkClone());
}
}
// Step 2 - iterate over the added changes and add them to the container.
Iterator addObjects = changeRecord.getAddObjectList().keySet().iterator();
while (addObjects.hasNext()) {
objectChanges = (ObjectChangeSet) addObjects.next();
Object object = null;
if (shouldMergeCascadeParts) {
object = mergeCascadeParts(objectChanges, mergeManager, parentSession);
}
if (object == null) {
// Retrieve the object to be added to the collection.
object = objectChanges.getTargetVersionOfSourceObject(mergeManager.getSession(), false);
}
// I am assuming that at this point the above merge will have created a new object if required
if (mergeManager.shouldMergeChangesIntoDistributedCache()) {
//bug#4458089 and 4454532- check if collection contains new item before adding during merge into distributed cache
if (!contains(object, valueOfTarget, mergeManager.getSession())) {
addInto(objectChanges.getNewKey(), object, valueOfTarget, mergeManager.getSession());
}
} else {
addInto(objectChanges.getNewKey(), object, valueOfTarget, mergeManager.getSession());
}
}
}
}
/**
* INTERNAL:
* Return the next object on the queue. The iterator is the one
* returned from #iteratorFor().
* Valid for some subclasses only.
*
* @see ContainerPolicy#iteratorFor(java.lang.Object)
*/
protected abstract Object next(Object iterator);
/**
* INTERNAL:
* Return the next object from the iterator.
* This is used to stream over a collection independent of JDK 1.1 and 1.2.
* The session may be required to unwrap for the wrapper policy.
*/
public Object next(Object iterator, AbstractSession session) {
Object next = next(iterator);
if (hasElementDescriptor()) {
next = getElementDescriptor().getObjectBuilder().unwrapObject(next, session);
}
return next;
}
/**
* INTERNAL:
* Return the next object on the queue. The iterator is the one
* returned from #iteratorFor().
*
* In the case of a Map, this will return a MapEntry to allow use of the key
*
* @see ContainerPolicy#iteratorFor(java.lang.Object)
* @see MapContainerPolicy.unwrapIteratorResult(Object object)
*/
public Object nextEntry(Object iterator){
return next(iterator);
}
/**
* INTERNAL:
* Return the next object on the queue. The iterator is the one
* returned from #iteratorFor().
*
* In the case of a Map, this will return a MapEntry to allow use of the key
*
* @see ContainerPolicy#iteratorFor(Object iterator, AbstractSession session)
* @see MapContainerPolicy.unwrapIteratorResult(Object object)
*/
public Object nextEntry(Object iterator, AbstractSession session) {
return next(iterator, session);
}
/**
* This can be used by collection such as cursored stream to gain control over execution.
*/
public boolean overridesRead() {
return false;
}
/**
* INTERNAL:
* Some subclasses need to post initialize mappings associated with them
*/
public void postInitialize(AbstractSession session) {
}
/**
* INTERNAL:
* Add the provided object to the deleted objects list on the commit manager.
* This may be overridden by subclasses to process a composite object
*
* @see MappedKeyMapContainerPolicy
* @param object
* @param manager
*/
public void postCalculateChanges(ObjectChangeSet ocs, ClassDescriptor referenceDescriptor, DatabaseMapping mapping, UnitOfWorkImpl uow){
if (mapping.isForeignReferenceMapping()){
Object clone = ocs.getUnitOfWorkClone();
uow.addDeletedPrivateOwnedObjects(mapping, clone);
}
}
/**
* INTERNAL:
* Add the provided object to the deleted objects list on the commit manager.
* This may be overridden by subclasses to process a composite object.
*/
public void postCalculateChanges(Object key, Object value, ClassDescriptor referenceDescriptor, DatabaseMapping mapping, UnitOfWorkImpl uow){
if (! mapping.isDirectCollectionMapping() && ! mapping.isAggregateCollectionMapping()){
uow.addDeletedPrivateOwnedObjects(mapping, value);
}
}
/**
* INTERNAL:
* Add the provided object to the deleted objects list on the commit manager.
* This may be overridden by subclasses to process a composite object.
*/
public void recordPrivateOwnedRemovals(Object object, ClassDescriptor referenceDescriptor, UnitOfWorkImpl uow){
if (referenceDescriptor != null){
referenceDescriptor.getObjectBuilder().recordPrivateOwnedRemovals(unwrapIteratorResult(object), uow, false);
}
}
/**
* Prepare and validate.
* Allow subclasses to override.
*/
public void prepare(DatabaseQuery query, AbstractSession session) throws QueryException {
if (query.isReadAllQuery() && (!query.isReportQuery()) && query.shouldUseWrapperPolicy()) {
setElementDescriptor(query.getDescriptor());
//make sure DataReadQuery points to this container policy
} else if (query.isDataReadQuery()) {
((DataReadQuery)query).setContainerPolicy(this);
}
}
/**
* Prepare and validate.
* Allow subclasses to override.
*/
public void prepareForExecution() throws QueryException {
}
/**
* INTERNAL:
* This method is used to check the key mapping to ensure that it does not write to
* a field that is written by another mapping.
* This method will be overridden by subclasses that deal MapKeys
*
*/
public void processAdditionalWritableMapKeyFields(AbstractSession session){
}
/**
* INTERNAL:
* Propagate the postDeleteEvent to any additional objects the query is aware of
* This method will be overridden by subclasses that deal MapKeys
*/
public void propogatePostDelete(DeleteObjectQuery query, Object object) {
}
/**
* INTERNAL:
* Propagate the postDeleteEvent to any additional objects the query is aware of
* This method will be overridden by subclasses that deal MapKeys
*/
public void propogatePostInsert(WriteObjectQuery query, Object object) {
}
/**
* INTERNAL:
* Propagate the postDeleteEvent to any additional objects the query is aware of
* This method will be overridden by subclasses that deal MapKeys
*/
public void propogatePostUpdate(WriteObjectQuery query, Object object) {
}
/**
* INTERNAL:
* Propagate the postDeleteEvent to any additional objects the query is aware of
* This method will be overridden by subclasses that deal MapKeys
*/
public void propogatePreDelete(DeleteObjectQuery query, Object object) {
}
/**
* INTERNAL:
* Propagate the postDeleteEvent to any additional objects the query is aware of
* This method will be overridden by subclasses that deal MapKeys
*/
public void propogatePreInsert(WriteObjectQuery query, Object object) {
}
/**
* INTERNAL:
* Propagate the postDeleteEvent to any additional objects the query is aware of
* This method will be overridden by subclasses that deal MapKeys
*/
public void propogatePreUpdate(WriteObjectQuery query, Object object) {
}
/**
* INTERNAL:
* Returns false. Most container policies do not need to propagate events within the collections
* This will be overridden by subclasses
*/
public boolean propagatesEventsToCollection(){
return false;
}
/**
* This method is used to bridge the behavior between Attribute Change Tracking and
* deferred change tracking with respect to adding the same instance multiple times.
* Each ContainerPolicy type will implement specific behavior for the collection
* type it is wrapping. These methods are only valid for collections containing object references
*/
public void recordAddToCollectionInChangeRecord(ObjectChangeSet changeSetToAdd, CollectionChangeRecord collectionChangeRecord){
if (collectionChangeRecord.getRemoveObjectList().containsKey(changeSetToAdd)) {
collectionChangeRecord.getRemoveObjectList().remove(changeSetToAdd);
} else {
collectionChangeRecord.getAddObjectList().put(changeSetToAdd, changeSetToAdd);
}
}
/**
* This method is used to bridge the behavior between Attribute Change Tracking and
* deferred change tracking with respect to adding the same instance multiple times.
* Each ContainerPolicy type will implement specific behavior for the collection
* type it is wrapping. These methods are only valid for collections containing object references
*/
public void recordRemoveFromCollectionInChangeRecord(ObjectChangeSet changeSetToRemove, CollectionChangeRecord collectionChangeRecord){
if(collectionChangeRecord.getAddObjectList().containsKey(changeSetToRemove)) {
collectionChangeRecord.getAddObjectList().remove(changeSetToRemove);
} else {
collectionChangeRecord.getRemoveObjectList().put(changeSetToRemove, changeSetToRemove);
}
}
/**
* This method is used to bridge the behavior between Attribute Change Tracking and
* deferred change tracking with respect to adding the same instance multiple times.
* Each ContainerPolicy type will implement specific behavior for the collection
* type it is wrapping. These methods are only valid for collections containing object references
*/
public void recordUpdateToCollectionInChangeRecord(CollectionChangeEvent event, ObjectChangeSet changeSet, CollectionChangeRecord collectionChangeRecord){
if (event.getChangeType() == CollectionChangeEvent.ADD) {
recordAddToCollectionInChangeRecord(changeSet, collectionChangeRecord);
} else if (event.getChangeType() == CollectionChangeEvent.REMOVE) {
recordRemoveFromCollectionInChangeRecord(changeSet, collectionChangeRecord);
} else {
throw ValidationException.wrongCollectionChangeEventType(event.getChangeType());
}
}
/**
* This can be used by collection such as cursored stream to gain control over execution.
*/
public Object remoteExecute() {
return null;
}
/**
* INTERNAL:
* Remove element from container.
* Valid for some subclasses only.
*/
protected boolean removeFrom(Object key, Object element, Object container) {
throw QueryException.cannotRemoveFromContainer(element, container, this);
}
/**
* INTERNAL:
* Remove the object from the collection.
* This is used to remove from a collection independent of JDK 1.1 and 1.2.
* The session may be required to unwrap for the wrapper policy.
*/
public boolean removeFrom(Object key, Object element, Object container, AbstractSession session) {
Object objectToRemove = element;
if (hasElementDescriptor() && getElementDescriptor().hasWrapperPolicy()) {
// The wrapper for the object must be removed.
Object iterator = iteratorFor(container);
while (hasNext(iterator)) {
Object next = next(iterator);
if (getElementDescriptor().getObjectBuilder().unwrapObject(next, session).equals(element)) {
objectToRemove = next;
break;
}
}
}
return removeFrom(key, objectToRemove, container);
}
/**
* INTERNAL:
* Remove the object from the collection.
* This is used to remove from a collection independent of JDK 1.1 and 1.2.
* The session may be required to unwrap for the wrapper policy.
*/
public boolean removeFrom(Object element, Object container, AbstractSession session) {
return removeFrom(null, element, container, session);
}
/**
* INTERNAL:
* Returns whether this ContainerPolicy should requires data modification events when
* objects are added or deleted during update
* @return
*/
public boolean requiresDataModificationEvents(){
return false;
}
/**
* INTERNAL:
* Set the size constructor if available.
*/
protected void setConstructor(Constructor constructor) {
this.constructor = constructor;
}
/**
* INTERNAL:
* Set the class used for the container.
*/
public void setContainerClass(Class containerClass) {
throw QueryException.methodNotValid(this, "getContainerClass()");
}
/**
* INTERNAL:
* Used by the MW
*/
public void setContainerClassName(String containerClassName) {
throw QueryException.methodNotValid(this, "getContainerClassName()");
}
/**
* INTERNAL:
* Used for wrapping and unwrapping with the wrapper policy.
*/
public void setElementDescriptor(ClassDescriptor elementDescriptor) {
this.elementDescriptor = elementDescriptor;
}
/**
* INTERNAL:
* It is illegal to send this message to this receiver. Try one of my
* subclasses. Throws an exception.
*
* @see MapContainerPolicy
*/
public void setKeyName(String instanceVariableName, String elementClassName) {
throw ValidationException.containerPolicyDoesNotUseKeys(this, instanceVariableName);
}
/**
* INTERNAL:
* Sets the key name to be used to generate the key in a Map type container
* class. The key name, may be the name of a field or method.
* An instance of the class is provided in the case when the descriptor is being
* built in code.
*/
public void setKeyName(String instanceVariableName, Class elementClass) {
throw ValidationException.containerPolicyDoesNotUseKeys(this, instanceVariableName);
}
/**
* INTERNAL:
* Indicates whether addAll method should be called to add entire collection,
* or it's possible to call addInto multiple times instead.
* @return
*/
public boolean shouldAddAll(){
return false;
}
/**
* INTERNAL:
* Return whether data for a map key must be included on a Delete data modification event
* This will be overridden by subclasses that handle maps.
*/
public boolean shouldIncludeKeyInDeleteEvent(){
return false;
}
/**
* INTERNAL:
* Certain types of container policies require an extra update statement after a relationship
* is inserted. Return whether this update statement is required.
*/
public boolean shouldUpdateForeignKeysPostInsert(){
return false;
}
/**
* INTERNAL:
* Return the size of container.
*/
public int sizeFor(Object container) {
throw QueryException.methodNotValid(this, "sizeFor(Object container)");
}
@Override
public String toString() {
return Helper.getShortClassName(this.getClass()) + "(" + toStringInfo() + ")";
}
protected Object toStringInfo() {
return "";
}
/**
* INTERNAL:
* Update the joined mapping indices
* This method is a no-op, but will be overridden by subclasses
*/
public int updateJoinedMappingIndexesForMapKey(Map<DatabaseMapping, Object> indexList, int index){
return 0;
}
/**
* INTERNAL:
* MapContainerPolicy's iterator iterates on the Entries of a Map.
* This method returns the object from the iterator
*
* @see MapContainerPolicy.nextWrapped(Object iterator)
*/
public Object unwrapElement(Object object){
return object;
}
/**
* INTERNAL:
* Depending on the container, the entries returned of iteration using the ContainerPolicy.iteratorFor() method
* may be wrapped. This method unwraps the values.
*
* @see MapContainerPolicy.unwrapIteratorResult(Object object)
*/
public Object unwrapIteratorResult(Object object){
return object;
}
/**
* INTERNAL:
* This method is used to load a relationship from a list of PKs. This list
* may be available if the relationship has been cached.
*/
public Object valueFromPKList(Object[] pks, AbstractSession session){
Object result = containerInstance(pks.length);
for (int index = 0; index < pks.length; ++index){
Object pk = null;
if (elementDescriptor.hasCMPPolicy()){
pk = elementDescriptor.getCMPPolicy().createPrimaryKeyFromId(pks[index], session);
}else{
pk = pks[index];
}
ReadObjectQuery query = new ReadObjectQuery();
query.setReferenceClass(elementDescriptor.getJavaClass());
query.setSelectionId(pk);
query.setIsExecutionClone(true);
addInto(session.executeQuery(query), result, session);
}
return result;
}
/**
* INTERNAL:
* Return a Vector populated with the contents of container.
* Added for bug 2766379, must implement a version of vectorFor that
* handles wrapped objects.
*/
public Vector vectorFor(Object container, AbstractSession session) {
Vector result = new Vector(sizeFor(container));
for (Object iter = iteratorFor(container); hasNext(iter);) {
result.addElement(next(iter, session));
}
return result;
}
/**
* INTERNAL:
* convenience method to copy the keys and values from a Map into an AbstractRecord
* @param mappingData a Map containing a database field as the key and the value of that field as the value
* @param databaseRow
*/
public static void copyMapDataToRow(Map mappingData, AbstractRecord databaseRow){
if (mappingData != null){
for (Iterator<Map.Entry> keys = mappingData.entrySet().iterator(); keys.hasNext();) {
Map.Entry entry = keys.next();
Object entryKey = entry.getKey();
Object entryValue = entry.getValue();
databaseRow.put(entryKey, entryValue);
}
}
}
}