oracle.toplink.essentials.mappings.AggregateObjectMapping Maven / Gradle / Ivy
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package oracle.toplink.essentials.mappings;
import java.util.*;
import oracle.toplink.essentials.exceptions.*;
import oracle.toplink.essentials.expressions.*;
import oracle.toplink.essentials.internal.helper.*;
import oracle.toplink.essentials.internal.queryframework.JoinedAttributeManager;
import oracle.toplink.essentials.internal.sessions.*;
import oracle.toplink.essentials.internal.descriptors.ObjectBuilder;
import oracle.toplink.essentials.sessions.DatabaseRecord;
import oracle.toplink.essentials.queryframework.*;
import oracle.toplink.essentials.internal.sessions.AbstractRecord;
import oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl;
import oracle.toplink.essentials.internal.sessions.AbstractSession;
import oracle.toplink.essentials.descriptors.ClassDescriptor;
/**
* Purpose:Two objects can be considered to be related by aggregation if there is a strict
* 1:1 relationship between the objects. This means that if the source (parent)
* object exists, then the target (child or owned) object must exist.
*
* In TopLink, it also means the data for the owned object is in the same table as
* the parent.
*
* @author Sati
* @since TOPLink/Java 1.0
*/
public class AggregateObjectMapping extends AggregateMapping implements RelationalMapping {
/**
* If all the fields in the database row for the aggregate object are NULL,
* then, by default, TopLink will place a null in the appropriate source object
* (as opposed to an aggregate object filled with nulls).
* To change this behavior, set the value of this variable to false. Then TopLink
* will build a new instance of the aggregate object that is filled with nulls
* and place it in the source object.
*/
protected boolean isNullAllowed;
/** Map the name of a field in the aggregate descriptor to a field in the source table. */
protected transient Map aggregateToSourceFieldNames;
/**
* Default constructor.
*/
public AggregateObjectMapping() {
aggregateToSourceFieldNames = new HashMap(5);
isNullAllowed = true;
}
/**
* INTERNAL:
*/
public boolean isRelationalMapping() {
return true;
}
/**
* PUBLIC:
* Add a field name translation that maps from a field name in the
* source table to a field name in the aggregate descriptor.
*/
public void addFieldNameTranslation(String sourceFieldName, String aggregateFieldName) {
String unQualifiedAggregateFieldName = aggregateFieldName.substring(aggregateFieldName.lastIndexOf('.') + 1);// -1 is returned for no ".".
getAggregateToSourceFieldNames().put(unQualifiedAggregateFieldName, sourceFieldName);
}
/**
* INTERNAL:
* Return whether all the aggregate fields in the specified
* row are NULL.
*/
protected boolean allAggregateFieldsAreNull(AbstractRecord databaseRow) {
for (Enumeration fieldsEnum = getReferenceFields().elements();
fieldsEnum.hasMoreElements();) {
DatabaseField field = (DatabaseField)fieldsEnum.nextElement();
Object value = databaseRow.get(field);
if (value != null) {
return false;
}
}
return true;
}
/**
* PUBLIC:
* If all the fields in the database row for the aggregate object are NULL,
* then, by default, TopLink will place a null in the appropriate source object
* (as opposed to an aggregate object filled with nulls). This behavior can be
* explicitly set by calling #allowNull().
* To change this behavior, call #dontAllowNull(). Then TopLink
* will build a new instance of the aggregate object that is filled with nulls
* and place it in the source object.
* In either situation, when writing, TopLink will place a NULL in all the
* fields in the database row for the aggregate object.
*/
public void allowNull() {
setIsNullAllowed(true);
}
/**
* INTERNAL:
* Return whether the query's backup object has an attribute
* value of null.
*/
protected boolean backupAttributeValueIsNull(WriteObjectQuery query) {
if (query.getSession().isUnitOfWork()) {
Object backupAttributeValue = getAttributeValueFromObject(query.getBackupClone());
if (backupAttributeValue == null) {
return true;
}
}
return false;
}
/**
* INTERNAL:
* Build and return an aggregate object from the specified row.
* If a null value is allowed and
* all the appropriate fields in the row are NULL, return a null.
* Otherwise, simply create a new aggregate object and return it.
*/
protected Object buildAggregateFromRow(AbstractRecord databaseRow, Object targetObject, JoinedAttributeManager joinManager, boolean buildShallowOriginal, AbstractSession session) throws DatabaseException {
// check for all NULLs
if (isNullAllowed() && allAggregateFieldsAreNull(databaseRow)) {
return null;
}
// If refreshing, maintain object identity;
// otherwise construct a new aggregate object.
Object aggregate = null;
ClassDescriptor descriptor = getReferenceDescriptor();
boolean refreshing = true;
if (descriptor.hasInheritance()) {
Class newAggregateClass = descriptor.getInheritancePolicy().classFromRow(databaseRow, session);
descriptor = getReferenceDescriptor(newAggregateClass, session);
if (joinManager.getBaseQuery().shouldRefreshIdentityMapResult()) {
aggregate = getMatchingAttributeValueFromObject(databaseRow, targetObject, session, descriptor);
if ((aggregate != null) && (aggregate.getClass() != newAggregateClass)) {
// if the class has changed out from underneath us, we cannot preserve object identity
// build a new instance of the *new* class
aggregate = descriptor.getObjectBuilder().buildNewInstance();
refreshing = false;
}
}
} else {
if (joinManager.getBaseQuery().shouldRefreshIdentityMapResult()) {
aggregate = getMatchingAttributeValueFromObject(databaseRow, targetObject, session, descriptor);
}
}
if (aggregate == null) {
aggregate = descriptor.getObjectBuilder().buildNewInstance();
refreshing = false;
}
ObjectBuildingQuery nestedQuery = joinManager.getBaseQuery();
nestedQuery.setSession(session); //ensure the correct session is set on the query.
if (joinManager.getBaseQuery().isObjectLevelReadQuery()){
if (joinManager.isAttributeJoined(getDescriptor(), getAttributeName()) ){
// A nested query must be built to pass to the descriptor that looks like the real query execution would.
nestedQuery = (ObjectLevelReadQuery)((ObjectLevelReadQuery)joinManager.getBaseQuery()).deepClone();
// Must cascade the nested partial/join expression and filter the nested ones.
((ObjectLevelReadQuery)nestedQuery).getJoinedAttributeManager().setJoinedAttributeExpressions_(extractNestedExpressions(joinManager.getJoinedAttributeExpressions(), joinManager.getBaseExpressionBuilder(), false));
nestedQuery.setDescriptor(descriptor);
}
}
if (buildShallowOriginal) {
descriptor.getObjectBuilder().buildAttributesIntoShallowObject(aggregate, databaseRow, nestedQuery);
} else if (session.isUnitOfWork()) {
descriptor.getObjectBuilder().buildAttributesIntoWorkingCopyClone(aggregate, nestedQuery, joinManager, databaseRow, (UnitOfWorkImpl)session, refreshing);
} else {
descriptor.getObjectBuilder().buildAttributesIntoObject(aggregate, databaseRow, nestedQuery, joinManager, refreshing);
}
return aggregate;
}
/**
* INTERNAL:
* Build and return a database row with all the reference
* fields set to nulls.
*/
protected AbstractRecord buildNullReferenceRow() {
AbstractRecord result = new DatabaseRecord(getReferenceFields().size());
for (Enumeration stream = getReferenceFields().elements(); stream.hasMoreElements();) {
result.put((DatabaseField)stream.nextElement(), null);
}
return result;
}
/**
* INTERNAL:
* Used to allow object level comparisons.
* In the case of an Aggregate which has no primary key must do an attribute
* by attribute comparison.
*/
public Expression buildObjectJoinExpression(Expression expression, Object value, AbstractSession session) {
Expression attributeByAttributeComparison = null;
Expression join = null;
Object attributeValue = null;
// value need not be unwrapped as it is an aggregate, nor should it
// influence a call to getReferenceDescriptor.
ClassDescriptor referenceDescriptor = getReferenceDescriptor();
if ((value != null) && !referenceDescriptor.getJavaClass().isInstance(value)) {
throw QueryException.incorrectClassForObjectComparison(expression, value, this);
}
Enumeration mappings = referenceDescriptor.getMappings().elements();
for (; mappings.hasMoreElements();) {
DatabaseMapping mapping = (DatabaseMapping)mappings.nextElement();
if (value == null) {
attributeValue = null;
} else {
attributeValue = mapping.getAttributeValueFromObject(value);
}
join = expression.get(mapping.getAttributeName()).equal(attributeValue);
if (attributeByAttributeComparison == null) {
attributeByAttributeComparison = join;
} else {
attributeByAttributeComparison = attributeByAttributeComparison.and(join);
}
}
return attributeByAttributeComparison;
}
/**
* INTERNAL:
* Used to allow object level comparisons.
*/
public Expression buildObjectJoinExpression(Expression expression, Expression argument, AbstractSession session) {
Expression attributeByAttributeComparison = null;
//Enumeration mappingsEnum = getSourceToTargetKeyFields().elements();
Enumeration mappingsEnum = getReferenceDescriptor().getMappings().elements();
for (; mappingsEnum.hasMoreElements();) {
DatabaseMapping mapping = (DatabaseMapping)mappingsEnum.nextElement();
String attributeName = mapping.getAttributeName();
Expression join = expression.get(attributeName).equal(argument.get(attributeName));
if (attributeByAttributeComparison == null) {
attributeByAttributeComparison = join;
} else {
attributeByAttributeComparison = attributeByAttributeComparison.and(join);
}
}
return attributeByAttributeComparison;
}
/**
* INTERNAL:
* Build and return a database row built with the values from
* the specified attribute value.
*/
protected AbstractRecord buildRowFromAggregate(Object object, Object attributeValue, AbstractSession session) throws DescriptorException {
return buildRowFromAggregate(object, attributeValue, session, false);
}
/**
* INTERNAL:
* Build and return a database row built with the values from
* the specified attribute value.
*/
protected AbstractRecord buildRowFromAggregate(Object object, Object attributeValue, AbstractSession session, boolean forceWriteOfReadOnlyClasses) throws DescriptorException {
if (attributeValue == null) {
if (isNullAllowed()) {
return buildNullReferenceRow();
} else {
throw DescriptorException.nullForNonNullAggregate(object, this);
}
} else {
if ((!forceWriteOfReadOnlyClasses) && (session.isClassReadOnly(attributeValue.getClass()))) {
return new DatabaseRecord(1);
} else {
return getObjectBuilder(attributeValue, session).buildRow(attributeValue, session);
}
}
}
/**
* INTERNAL:
* Build and return a database row built with the values from
* the specified attribute value.
*/
protected AbstractRecord buildRowFromAggregateWithChangeRecord(ChangeRecord changeRecord, ObjectChangeSet objectChangeSet, AbstractSession session) throws DescriptorException {
return buildRowFromAggregateWithChangeRecord(changeRecord, objectChangeSet, session, false);
}
/**
* INTERNAL:
* Build and return a database row built with the values from
* the specified attribute value.
*/
protected AbstractRecord buildRowFromAggregateWithChangeRecord(ChangeRecord changeRecord, ObjectChangeSet objectChangeSet, AbstractSession session, boolean forceWriteOfReadOnlyClasses) throws DescriptorException {
if (objectChangeSet == null) {
if (isNullAllowed()) {
return buildNullReferenceRow();
} else {
Object object = ((ObjectChangeSet)changeRecord.getOwner()).getUnitOfWorkClone();
throw DescriptorException.nullForNonNullAggregate(object, this);
}
} else {
if ((!forceWriteOfReadOnlyClasses) && (session.isClassReadOnly(objectChangeSet.getClassType(session)))) {
return new DatabaseRecord(1);
} else {
return getReferenceDescriptor(objectChangeSet.getClassType(session), session).getObjectBuilder().buildRowWithChangeSet(objectChangeSet, session);
}
}
}
/**
* INTERNAL:
* Build and return a database row built with the changed values from
* the specified attribute value.
*/
protected AbstractRecord buildRowFromAggregateForUpdate(WriteObjectQuery query, Object attributeValue) throws DescriptorException {
if (attributeValue == null) {
if (isNullAllowed()) {
if (backupAttributeValueIsNull(query)) {
return new DatabaseRecord(1);// both attributes are null - no update required
} else {
return buildNullReferenceRow();
}
} else {
throw DescriptorException.nullForNonNullAggregate(query.getObject(), this);
}
} else if ((query.getBackupClone() != null) && ((getMatchingBackupAttributeValue(query, attributeValue) == null) || !(attributeValue.getClass().equals(getMatchingBackupAttributeValue(query, attributeValue).getClass())))) {
return getObjectBuilder(attributeValue, query.getSession()).buildRow(attributeValue, query.getSession());
} else {
if (query.getSession().isClassReadOnly(attributeValue.getClass())) {
return new DatabaseRecord(1);
}
WriteObjectQuery clonedQuery = (WriteObjectQuery)query.clone();
clonedQuery.setObject(attributeValue);
if (query.getSession().isUnitOfWork()) {
Object backupAttributeValue = getMatchingBackupAttributeValue(query, attributeValue);
if (backupAttributeValue == null) {
backupAttributeValue = getObjectBuilder(attributeValue, query.getSession()).buildNewInstance();
}
clonedQuery.setBackupClone(backupAttributeValue);
}
return getObjectBuilder(attributeValue, query.getSession()).buildRowForUpdate(clonedQuery);
}
}
/**
* INTERNAL:
* Clone the attribute from the original and assign it to the clone.
*/
public void buildClone(Object original, Object clone, UnitOfWorkImpl unitOfWork, JoinedAttributeManager joinedAttributeManager) {
Object attributeValue = getAttributeValueFromObject(original);
Object aggregateClone = buildClonePart(original, attributeValue, unitOfWork);
if (aggregateClone != null) {
ClassDescriptor descriptor = getReferenceDescriptor(aggregateClone, unitOfWork);
descriptor.getObjectChangePolicy().setAggregateChangeListener(clone, aggregateClone, unitOfWork, descriptor, getAttributeName());
}
setAttributeValueInObject(clone, aggregateClone);
}
/**
* INTERNAL:
* A combination of readFromRowIntoObject and buildClone.
*
* buildClone assumes the attribute value exists on the original and can
* simply be copied.
*
* readFromRowIntoObject assumes that one is building an original.
*
* Both of the above assumptions are false in this method, and actually
* attempts to do both at the same time.
*
* Extract value from the row and set the attribute to this value in the
* working copy clone.
* In order to bypass the shared cache when in transaction a UnitOfWork must
* be able to populate working copies directly from the row.
*/
public void buildCloneFromRow(AbstractRecord databaseRow, JoinedAttributeManager joinManager, Object clone, ObjectBuildingQuery sourceQuery, UnitOfWorkImpl unitOfWork, AbstractSession executionSession) {
// This method is a combination of buildggregateFromRow and
// buildClonePart on the super class.
// none of buildClonePart used, as not an orignal new object, nor
// do we worry about creating heavy clones for aggregate objects.
Object clonedAttributeValue = buildAggregateFromRow(databaseRow, clone, joinManager, false, executionSession);
ClassDescriptor descriptor = getReferenceDescriptor(clonedAttributeValue, unitOfWork);
descriptor.getObjectChangePolicy().setAggregateChangeListener(clone, clonedAttributeValue, unitOfWork, descriptor, getAttributeName());
setAttributeValueInObject(clone, clonedAttributeValue);
return;
}
/**
* INTERNAL:
* Builds a shallow original object. Only direct attributes and primary
* keys are populated. In this way the minimum original required for
* instantiating a working copy clone can be built without placing it in
* the shared cache (no concern over cycles).
*/
public void buildShallowOriginalFromRow(AbstractRecord databaseRow, Object original, JoinedAttributeManager joinManager, AbstractSession executionSession) {
Object aggregate = buildAggregateFromRow(databaseRow, original, joinManager, true, executionSession);// shallow only.
setAttributeValueInObject(original, aggregate);
}
/**
* INTERNAL:
* Build and return a "template" database row with all the fields
* set to null.
*/
protected AbstractRecord buildTemplateInsertRow(AbstractSession session) {
AbstractRecord result = getReferenceDescriptor().getObjectBuilder().buildTemplateInsertRow(session);
List processedMappings = (List)getReferenceDescriptor().getMappings().clone();
if (getReferenceDescriptor().hasInheritance()) {
Enumeration children = getReferenceDescriptor().getInheritancePolicy().getChildDescriptors().elements();
while (children.hasMoreElements()) {
Enumeration mappings = ((ClassDescriptor)children.nextElement()).getMappings().elements();
while (mappings.hasMoreElements()) {
DatabaseMapping mapping = (DatabaseMapping)mappings.nextElement();
// Only write mappings once.
if (!processedMappings.contains(mapping)) {
mapping.writeInsertFieldsIntoRow(result, session);
processedMappings.add(mapping);
}
}
}
}
return result;
}
/**
* INTERNAL:
* Cascade perform delete through mappings that require the cascade
*/
public void cascadePerformRemoveIfRequired(Object object, UnitOfWorkImpl uow, IdentityHashtable visitedObjects){
//objects referenced by this mapping are not registered as they have
// no identity, however mappings from the referenced object may need cascading.
Object objectReferenced = getRealAttributeValueFromObject(object, uow);
if ((objectReferenced == null)){
return ;
}
if ( ! visitedObjects.contains(objectReferenced)){
visitedObjects.put(objectReferenced, objectReferenced);
ObjectBuilder builder = getReferenceDescriptor(objectReferenced.getClass(), uow).getObjectBuilder();
builder.cascadePerformRemove(objectReferenced, uow, visitedObjects);
}
}
/**
* INTERNAL:
* Cascade registerNew for Create through mappings that require the cascade
*/
public void cascadeRegisterNewIfRequired(Object object, UnitOfWorkImpl uow, IdentityHashtable visitedObjects){
//aggregate objects are not registered but their mappings should be.
Object objectReferenced = getRealAttributeValueFromObject(object, uow);
if ( (objectReferenced == null) ){
return ;
}
if ( ! visitedObjects.contains(objectReferenced)){
visitedObjects.put(objectReferenced, objectReferenced);
ObjectBuilder builder = getReferenceDescriptor(objectReferenced.getClass(), uow).getObjectBuilder();
builder.cascadeRegisterNewForCreate(objectReferenced, uow, visitedObjects);
}
}
/**
* INTERNAL:
* Return the fields handled by the mapping.
*/
protected Vector collectFields() {
return getReferenceFields();
}
/**
* PUBLIC:
* If all the fields in the database row for the aggregate object are NULL,
* then, by default, TopLink will place a null in the appropriate source object
* (as opposed to an aggregate object filled with nulls). This behavior can be
* explicitly set by calling #allowNull().
* To change this behavior, call #dontAllowNull(). Then TopLink
* will build a new instance of the aggregate object that is filled with nulls
* and place it in the source object.
* In either situation, when writing, TopLink will place a NULL in all the
* fields in the database row for the aggregate object.
*/
public void dontAllowNull() {
setIsNullAllowed(false);
}
/**
* INTERNAL:
* Return a collection of the aggregate to source field name associations.
*/
public Vector getAggregateToSourceFieldNameAssociations() {
Vector associations = new Vector(getAggregateToSourceFieldNames().size());
Iterator aggregateEnum = getAggregateToSourceFieldNames().keySet().iterator();
Iterator sourceEnum = getAggregateToSourceFieldNames().values().iterator();
while (aggregateEnum.hasNext()) {
associations.addElement(new Association(aggregateEnum.next(), sourceEnum.next()));
}
return associations;
}
/**
* INTERNAL:
* Return the hashtable that stores aggregate field name to source field name.
*/
public Map getAggregateToSourceFieldNames() {
return aggregateToSourceFieldNames;
}
/**
* INTERNAL:
* Return the classification for the field contained in the mapping.
* This is used to convert the row value to a consistent Java value.
*/
public Class getFieldClassification(DatabaseField fieldToClassify) {
DatabaseMapping mapping = getReferenceDescriptor().getObjectBuilder().getMappingForField(fieldToClassify);
if (mapping == null) {
return null;// Means that the mapping is read-only
}
return mapping.getFieldClassification(fieldToClassify);
}
/**
* INTERNAL:
* This is used to preserve object identity during a refreshObject()
* query. Return the object corresponding to the specified database row.
* The default is to simply return the attribute value.
*/
protected Object getMatchingAttributeValueFromObject(AbstractRecord row, Object targetObject, AbstractSession session, ClassDescriptor descriptor) {
return getAttributeValueFromObject(targetObject);
}
/**
* INTERNAL:
* This is used to match up objects during an update in a UOW.
* Return the object corresponding to the specified attribute value.
* The default is to simply return the backup attribute value.
*/
protected Object getMatchingBackupAttributeValue(WriteObjectQuery query, Object attributeValue) {
return getAttributeValueFromObject(query.getBackupClone());
}
/**
* INTERNAL:
* Since aggregate object mappings clone their descriptors, for inheritance the correct child clone must be found.
*/
protected ClassDescriptor getReferenceDescriptor(Class theClass, AbstractSession session) {
if (getReferenceDescriptor().getJavaClass().equals(theClass)) {
return getReferenceDescriptor();
}
ClassDescriptor subclassDescriptor = getReferenceDescriptor().getInheritancePolicy().getSubclassDescriptor(theClass);
if (subclassDescriptor == null) {
throw DescriptorException.noSubClassMatch(theClass, this);
} else {
return subclassDescriptor;
}
}
/**
* INTERNAL:
* Return the fields used to build the aggregate object.
*/
protected Vector getReferenceFields() {
return getReferenceDescriptor().getAllFields();
}
/**
* INTERNAL:
* Return if the mapping has any ownership or other dependency over its target object(s).
*/
public boolean hasDependency() {
return getReferenceDescriptor().hasDependencyOnParts();
}
/**
* INTERNAL:
* For an aggregate mapping the reference descriptor is cloned. The cloned descriptor is then
* assigned primary keys and table names before initialize. Once the cloned descriptor is initialized
* it is assigned as reference descriptor in the aggregate mapping. This is a very specific
* behaviour for aggregate mappings. The original descriptor is used only for creating clones and
* after that the aggregate mapping never uses it.
* Some initialization is done in postInitialize to ensure the target descriptor's references are initialized.
*/
public void initialize(AbstractSession session) throws DescriptorException {
super.initialize(session);
ClassDescriptor clonedDescriptor = (ClassDescriptor)getReferenceDescriptor().clone();
if (clonedDescriptor.isChildDescriptor()) {
ClassDescriptor parentDescriptor = session.getDescriptor(clonedDescriptor.getInheritancePolicy().getParentClass());
initializeParentInheritance(parentDescriptor, clonedDescriptor, session);
}
setReferenceDescriptor(clonedDescriptor);
initializeReferenceDescriptor(clonedDescriptor);
clonedDescriptor.preInitialize(session);
clonedDescriptor.initialize(session);
translateFields(clonedDescriptor, session);
if (clonedDescriptor.hasInheritance() && clonedDescriptor.getInheritancePolicy().hasChildren()) {
//clone child descriptors
initializeChildInheritance(clonedDescriptor, session);
}
setFields(collectFields());
}
/**
* INTERNAL:
* For an aggregate mapping the reference descriptor is cloned.
* If the reference descriptor is involved in an inheritance tree,
* all the parent and child descriptors are cloned also.
* The cloned descriptors are then assigned primary keys and
* table names before initialize.
* This is a very specific behaviour for aggregate mappings.
*/
public void initializeChildInheritance(ClassDescriptor parentDescriptor, AbstractSession session) throws DescriptorException {
//recursive call to the further childern descriptors
if (parentDescriptor.getInheritancePolicy().hasChildren()) {
//setFields(clonedChildDescriptor.getFields());
Vector childDescriptors = parentDescriptor.getInheritancePolicy().getChildDescriptors();
Vector cloneChildDescriptors = oracle.toplink.essentials.internal.helper.NonSynchronizedVector.newInstance();
for (Enumeration enumtr = childDescriptors.elements(); enumtr.hasMoreElements();) {
ClassDescriptor clonedChildDescriptor = (ClassDescriptor)((ClassDescriptor)enumtr.nextElement()).clone();
clonedChildDescriptor.getInheritancePolicy().setParentDescriptor(parentDescriptor);
initializeReferenceDescriptor(clonedChildDescriptor);
clonedChildDescriptor.preInitialize(session);
clonedChildDescriptor.initialize(session);
translateFields(clonedChildDescriptor, session);
cloneChildDescriptors.addElement(clonedChildDescriptor);
initializeChildInheritance(clonedChildDescriptor, session);
}
parentDescriptor.getInheritancePolicy().setChildDescriptors(cloneChildDescriptors);
}
}
/**
* INTERNAL:
* For an aggregate mapping the reference descriptor is cloned.
* If the reference descriptor is involved in an inheritance tree,
* all the parent and child descriptors are cloned also.
* The cloned descriptors are then assigned primary keys and
* table names before initialize.
* This is a very specific behaviour for aggregate mappings.
*/
public void initializeParentInheritance(ClassDescriptor parentDescriptor, ClassDescriptor childDescriptor, AbstractSession session) throws DescriptorException {
ClassDescriptor clonedParentDescriptor = (ClassDescriptor)parentDescriptor.clone();
//recursive call to the further parent descriptors
if (clonedParentDescriptor.getInheritancePolicy().isChildDescriptor()) {
ClassDescriptor parentToParentDescriptor = session.getDescriptor(clonedParentDescriptor.getJavaClass());
initializeParentInheritance(parentToParentDescriptor, parentDescriptor, session);
}
initializeReferenceDescriptor(clonedParentDescriptor);
Vector children = oracle.toplink.essentials.internal.helper.NonSynchronizedVector.newInstance(1);
children.addElement(childDescriptor);
clonedParentDescriptor.getInheritancePolicy().setChildDescriptors(children);
clonedParentDescriptor.preInitialize(session);
clonedParentDescriptor.initialize(session);
translateFields(clonedParentDescriptor, session);
}
/**
* INTERNAL:
* Initialize the cloned reference descriptor with table names and primary keys
*/
protected void initializeReferenceDescriptor(ClassDescriptor clonedDescriptor) {
// Must ensure default tables remains the same.
clonedDescriptor.setDefaultTable(getDescriptor().getDefaultTable());
clonedDescriptor.setTables(getDescriptor().getTables());
clonedDescriptor.setPrimaryKeyFields(getDescriptor().getPrimaryKeyFields());
}
/**
* INTERNAL:
* Related mapping should implement this method to return true.
*/
public boolean isAggregateObjectMapping() {
return true;
}
/**
* INTERNAL:
* Return if this mapping supports change tracking.
*/
public boolean isChangeTrackingSupported() {
return false;
}
/**
* INTERNAL
* Return true if this mapping supports cascaded version optimistic locking.
*/
public boolean isCascadedLockingSupported() {
return true;
}
/**
* INTERNAL:
* Return setting.
*/
public boolean isNullAllowed() {
return isNullAllowed;
}
/**
* INTERNAL:
* For an aggregate mapping the reference descriptor is cloned. The cloned descriptor is then
* assigned primary keys and table names before initialize. Once the cloned descriptor is initialized
* it is assigned as reference descriptor in the aggregate mapping. This is a very specific
* behaviour for aggregate mappings. The original descriptor is used only for creating clones and
* after that the aggregate mapping never uses it.
* Some initialization is done in postInitialize to ensure the target descriptor's references are initialized.
*/
public void postInitialize(AbstractSession session) throws DescriptorException {
super.postInitialize(session);
if (getReferenceDescriptor() != null) {
getReferenceDescriptor().postInitialize(session);
}
}
/**
* INTERNAL:
* Build an aggregate object from the specified return row and put it
* in the specified target object.
* Return row is merged into object after execution of insert or update call
* accordiing to ReturningPolicy.
*/
public Object readFromReturnRowIntoObject(AbstractRecord row, Object targetObject, ReadObjectQuery query, Collection handledMappings) throws DatabaseException {
Object aggregate = getAttributeValueFromObject(targetObject);
if (aggregate == null) {
aggregate = readFromRowIntoObject(row, null, targetObject, query);
handledMappings.add(this);
return aggregate;
}
for (int i = 0; i < getReferenceFields().size(); i++) {
DatabaseField field = (DatabaseField)getReferenceFields().elementAt(i);
if (row.containsKey(field)) {
getObjectBuilder(aggregate, query.getSession()).assignReturnValueForField(aggregate, query, row, field, handledMappings);
}
}
if (isNullAllowed()) {
boolean allAttributesNull = true;
for (int i = 0; (i < getReferenceFields().size()) && allAttributesNull; i++) {
DatabaseField field = (DatabaseField)fields.elementAt(i);
if (row.containsKey(field)) {
allAttributesNull = row.get(field) == null;
} else {
Object fieldValue = valueFromObject(targetObject, field, query.getSession());
if (fieldValue == null) {
Object baseValue = getDescriptor().getObjectBuilder().getBaseValueForField(field, targetObject);
if (baseValue != null) {
DatabaseMapping baseMapping = getDescriptor().getObjectBuilder().getBaseMappingForField(field);
if (baseMapping.isForeignReferenceMapping()) {
ForeignReferenceMapping refMapping = (ForeignReferenceMapping)baseMapping;
if (refMapping.usesIndirection()) {
allAttributesNull = refMapping.getIndirectionPolicy().objectIsInstantiated(baseValue);
}
}
}
} else {
allAttributesNull = false;
}
}
}
if (allAttributesNull) {
aggregate = null;
setAttributeValueInObject(targetObject, aggregate);
}
}
handledMappings.add(this);
return aggregate;
}
/**
* INTERNAL:
* Build an aggregate object from the specified row and put it
* in the specified target object.
*/
public Object readFromRowIntoObject(AbstractRecord databaseRow, JoinedAttributeManager joinManager, Object targetObject, ObjectBuildingQuery sourceQuery, AbstractSession executionSession) throws DatabaseException {
Object aggregate = buildAggregateFromRow(databaseRow, targetObject, joinManager, false, executionSession);// don't just build a shallow original
setAttributeValueInObject(targetObject, aggregate);
return aggregate;
}
/**
* INTERNAL:
* Rehash any hashtables based on fields.
* This is used to clone descriptors for aggregates, which hammer field names.
*/
public void rehashFieldDependancies(AbstractSession session) {
getReferenceDescriptor().rehashFieldDependancies(session);
}
/**
* INTERNAL:
* Set a collection of the aggregate to source field name associations.
*/
public void setAggregateToSourceFieldNameAssociations(Vector fieldAssociations) {
Hashtable fieldNames = new Hashtable(fieldAssociations.size() + 1);
for (Enumeration associationsEnum = fieldAssociations.elements();
associationsEnum.hasMoreElements();) {
Association association = (Association)associationsEnum.nextElement();
fieldNames.put(association.getKey(), association.getValue());
}
setAggregateToSourceFieldNames(fieldNames);
}
/**
* INTERNAL:
* Set the hashtable that stores target field name to the source field name.
*/
protected void setAggregateToSourceFieldNames(Map aggregateToSource) {
aggregateToSourceFieldNames = aggregateToSource;
}
/**
* INTERNAL:
* Will be used by Gromit only.
*/
public void setIsNullAllowed(boolean aBoolean) {
isNullAllowed = aBoolean;
}
/**
* INTERNAL:
* If field names are different in the source and aggregate objects then the translation
* is done here. The aggregate field name is converted to source field name from the
* field name mappings stored.
*/
protected void translateFields(ClassDescriptor clonedDescriptor, AbstractSession session) {
for (Enumeration entry = clonedDescriptor.getFields().elements(); entry.hasMoreElements();) {
DatabaseField field = (DatabaseField)entry.nextElement();
String nameInAggregate = field.getName();
String nameInSource = (String)getAggregateToSourceFieldNames().get(nameInAggregate);
// Do not modify non-translated fields.
if (nameInSource != null) {
DatabaseField fieldInSource = new DatabaseField(nameInSource);
// Check if the translated field specified a table qualifier.
if (fieldInSource.getName().equals(nameInSource)) {
// No table so just set the field name.
field.setName(nameInSource);
} else {
// There is a table, so set the name and table.
field.setName(fieldInSource.getName());
field.setTable(clonedDescriptor.getTable(fieldInSource.getTable().getName()));
}
}
}
clonedDescriptor.rehashFieldDependancies(session);
}
/**
* INTERNAL:
* A subclass should implement this method if it wants different behaviour.
* Write the foreign key values from the attribute to the row.
*/
public void writeFromAttributeIntoRow(Object attribute, AbstractRecord row, AbstractSession session)
{
AbstractRecord targetRow = buildRowFromAggregate(null, attribute, session);
for (Enumeration stream = targetRow.keys(); stream.hasMoreElements(); ) {
DatabaseField field = (DatabaseField) stream.nextElement();
Object value = targetRow.get(field);
row.put(field, value);
}
}
/**
* INTERNAL:
* Extract value of the field from the object
*/
public Object valueFromObject(Object object, DatabaseField field, AbstractSession session) throws DescriptorException {
Object attributeValue = getAttributeValueFromObject(object);
if (attributeValue == null) {
if (isNullAllowed()) {
return null;
} else {
throw DescriptorException.nullForNonNullAggregate(object, this);
}
} else {
return getObjectBuilder(attributeValue, session).extractValueFromObjectForField(attributeValue, field, session);
}
}
/**
* INTERNAL:
* Get the attribute value from the object and add the appropriate
* values to the specified database row.
*/
public void writeFromObjectIntoRow(Object object, AbstractRecord databaseRow, AbstractSession session) throws DescriptorException {
if (isReadOnly()) {
return;
}
AbstractRecord targetRow = buildRowFromAggregate(object, getAttributeValueFromObject(object), session);
for (Enumeration stream = targetRow.keys(); stream.hasMoreElements();) {
DatabaseField field = (DatabaseField)stream.nextElement();
Object value = targetRow.get(field);
databaseRow.add(field, value);
}
}
/**
* INTERNAL:
* Get the attribute value from the object and add the appropriate
* values to the specified database row.
*/
public void writeFromObjectIntoRowWithChangeRecord(ChangeRecord changeRecord, AbstractRecord databaseRow, AbstractSession session) throws DescriptorException {
if (isReadOnly()) {
return;
}
AbstractRecord targetRow = buildRowFromAggregateWithChangeRecord(changeRecord, (ObjectChangeSet)((AggregateChangeRecord)changeRecord).getChangedObject(), session);
for (Enumeration stream = targetRow.keys(); stream.hasMoreElements();) {
DatabaseField field = (DatabaseField)stream.nextElement();
Object value = targetRow.get(field);
databaseRow.add(field, value);
}
}
/**
* INTERNAL:
* Get the attribute value from the object and add the changed
* values to the specified database row.
*/
public void writeFromObjectIntoRowForUpdate(WriteObjectQuery query, AbstractRecord databaseRow) throws DescriptorException {
if (isReadOnly()) {
return;
}
AbstractRecord targetRow = buildRowFromAggregateForUpdate(query, getAttributeValueFromObject(query.getObject()));
for (Enumeration stream = targetRow.keys(); stream.hasMoreElements();) {
DatabaseField field = (DatabaseField)stream.nextElement();
Object value = targetRow.get(field);
databaseRow.add(field, value);
}
}
/**
* INTERNAL:
* Write fields needed for insert into the template for with null values.
*/
public void writeInsertFieldsIntoRow(AbstractRecord databaseRow, AbstractSession session) {
if (isReadOnly()) {
return;
}
AbstractRecord targetRow = buildTemplateInsertRow(session);
for (Enumeration keyEnum = targetRow.keys(); keyEnum.hasMoreElements();) {
DatabaseField field = (DatabaseField)keyEnum.nextElement();
Object value = targetRow.get(field);
//CR-3286097 - Should use add not put, to avoid linear search.
databaseRow.add(field, value);
}
}
/**
* INTERNAL:
* Add a primary key join column (secondary field).
* If this contain primary keys and the descriptor(or its subclass) has multiple tables
* (secondary tables or joined inheritance strategy), this should also know the primary key
* join columns to handle some cases properly.
*/
public void addPrimaryKeyJoinField(DatabaseField primaryKeyField, DatabaseField secondaryField) {
// now it doesn't need to manage this as a separate table here,
// it's enough just to add the mapping to ObjectBuilder.mappingsByField
ObjectBuilder builder = getReferenceDescriptor().getObjectBuilder();
DatabaseMapping mapping = builder.getMappingForField(primaryKeyField);
if (mapping != null) {
builder.getMappingsByField().put(secondaryField, mapping);
}
}
}