@Override
public ClassDescriptor getDescriptor() {
if (isAttribute()) {
return null;
}
if (descriptor == null) {
// Look first for query keys, then mappings. Ultimately we should have query keys
// for everything and can dispense with the mapping part.
ForeignReferenceQueryKey queryKey = (ForeignReferenceQueryKey) getQueryKeyOrNull();
if (queryKey != null) {
descriptor =
convertToCastDescriptor(
getSession().getDescriptor(queryKey.getReferenceClass()), getSession());
return descriptor;
}
if (getMapping() == null) {
throw QueryException.invalidQueryKeyInExpression(this);
}
// We assume this is either a foreign reference or an aggregate mapping
descriptor = getMapping().getReferenceDescriptor();
if (getMapping().isVariableOneToOneMapping()) {
throw QueryException.cannotQueryAcrossAVariableOneToOneMapping(getMapping(), descriptor);
}
descriptor = convertToCastDescriptor(descriptor, getSession());
}
return descriptor;
}
/**
* INTERNAL Return the descriptor which contains this query key, look in the inheritance hierarchy
* of rootDescriptor for the descriptor.
*/
public ClassDescriptor convertToCastDescriptor(
ClassDescriptor rootDescriptor, AbstractSession session) {
if (castClass == null || rootDescriptor == null || rootDescriptor.getJavaClass() == castClass) {
return rootDescriptor;
}
ClassDescriptor castDescriptor = session.getClassDescriptor(castClass);
if (castDescriptor == null) {
throw QueryException.couldNotFindCastDescriptor(castClass, getBaseExpression());
}
if (!castDescriptor.hasInheritance()) {
throw QueryException.castMustUseInheritance(getBaseExpression());
}
ClassDescriptor parentDescriptor = castDescriptor.getInheritancePolicy().getParentDescriptor();
while (parentDescriptor != null) {
if (parentDescriptor == rootDescriptor) {
return castDescriptor;
}
parentDescriptor = parentDescriptor.getInheritancePolicy().getParentDescriptor();
}
ClassDescriptor childDescriptor = rootDescriptor;
while (childDescriptor != null) {
if (childDescriptor == castDescriptor) {
return rootDescriptor;
}
childDescriptor = childDescriptor.getInheritancePolicy().getParentDescriptor();
}
throw QueryException.couldNotFindCastDescriptor(castClass, getBaseExpression());
}
/**
* INTERNAL Return true if it uses a cast class and query is downcasting. It will look into
* inheritance hierarchy of the root descriptor.
*/
public boolean isDowncast(ClassDescriptor rootDescriptor, AbstractSession session) {
if (castClass == null) {
return false;
}
if (rootDescriptor.getJavaClass() == castClass) {
return false;
}
ClassDescriptor castDescriptor = session.getClassDescriptor(castClass);
if (castDescriptor == null) {
throw QueryException.couldNotFindCastDescriptor(castClass, getBaseExpression());
}
if (castDescriptor.getInheritancePolicy() == null) {
throw QueryException.castMustUseInheritance(getBaseExpression());
}
ClassDescriptor parentDescriptor = castDescriptor.getInheritancePolicy().getParentDescriptor();
while (parentDescriptor != null) {
if (parentDescriptor == rootDescriptor) {
return true;
}
parentDescriptor = parentDescriptor.getInheritancePolicy().getParentDescriptor();
}
throw QueryException.couldNotFindCastDescriptor(castClass, getBaseExpression());
}
public DatabaseMapping getMappingFromQueryKey() {
QueryKey queryKey = getQueryKeyOrNull();
if ((queryKey == null) || (!(queryKey instanceof DirectQueryKey))) {
throw QueryException.cannotConformExpression();
}
mapping =
queryKey
.getDescriptor()
.getObjectBuilder()
.getMappingForField(((DirectQueryKey) queryKey).getField());
if (mapping == null) {
throw QueryException.cannotConformExpression();
}
return mapping;
}
/** INTERNAL: Return if the expression is for a direct mapped attribute. */
public boolean isAttribute() {
if (isAttributeExpression == null) {
if (getSession() == null) {
// We can't tell, so say no.
return false;
}
QueryKey queryKey = getQueryKeyOrNull();
if (queryKey != null) {
isAttributeExpression = Boolean.valueOf(queryKey.isDirectQueryKey());
} else {
DatabaseMapping mapping = getMapping();
if (mapping != null) {
if (mapping.isVariableOneToOneMapping()) {
throw QueryException.cannotQueryAcrossAVariableOneToOneMapping(
mapping, mapping.getDescriptor());
} else {
isAttributeExpression = Boolean.valueOf(mapping.isDirectToFieldMapping());
}
} else {
isAttributeExpression = Boolean.FALSE;
}
}
}
return isAttributeExpression.booleanValue();
}
/**
* PUBLIC: Configure the query to use an instance of the specified container class to hold the
* result objects. The key used to index the value in the Map is the value returned by a call to
* the specified zero-argument method. The method must be implemented by the class (or a
* superclass) of the value to be inserted into the Map.
*
* <p>jdk1.2.x: The container class must implement (directly or indirectly) the Map interface.
*
* <p>jdk1.1.x: The container class must be a subclass of Hashtable.
*
* <p>The referenceClass must set before calling this method.
*/
public void useMapClass(Class concreteClass, String methodName) {
// the reference class has to be specified before coming here
if (getReferenceClass() == null) {
throw QueryException.referenceClassMissing(this);
}
ContainerPolicy policy = ContainerPolicy.buildPolicyFor(concreteClass);
policy.setKeyName(methodName, getReferenceClass().getName());
setContainerPolicy(policy);
}
/** Do any required validation for this node. Throw an exception if it's incorrect. */
public void validateNode() {
if ((getQueryKeyOrNull() == null) && (getMapping() == null)) {
throw QueryException.invalidQueryKeyInExpression(getName());
}
QueryKey queryKey = getQueryKeyOrNull();
DatabaseMapping mapping = getMapping();
Object theOneThatsNotNull = null;
boolean qkIsToMany = false;
if (queryKey != null) {
theOneThatsNotNull = queryKey;
qkIsToMany = queryKey.isManyToManyQueryKey() || queryKey.isOneToManyQueryKey();
}
boolean isNestedMapping = false;
if (mapping != null) {
// Bug 2847621 - Add Aggregate Collection to the list of valid items for outer join.
if (shouldUseOuterJoin
&& (!(mapping.isOneToOneMapping()
|| mapping.isOneToManyMapping()
|| mapping.isManyToManyMapping()
|| mapping.isAggregateCollectionMapping()
|| mapping.isDirectCollectionMapping()))) {
throw QueryException.outerJoinIsOnlyValidForOneToOneMappings(getMapping());
}
qkIsToMany = mapping.isCollectionMapping();
if (index != null) {
if (qkIsToMany) {
CollectionMapping collectionMapping = (CollectionMapping) getMapping();
if (collectionMapping.getListOrderField() != null) {
index.setField(collectionMapping.getListOrderField());
if (collectionMapping.shouldUseListOrderFieldTableExpression()) {
Expression newBase = getTable(collectionMapping.getListOrderField().getTable());
index.setBaseExpression(newBase);
} else {
addDerivedField(index);
}
} else {
throw QueryException.indexRequiresCollectionMappingWithListOrderField(
this, collectionMapping);
}
} else {
throw QueryException.indexRequiresCollectionMappingWithListOrderField(this, mapping);
}
}
isNestedMapping = mapping.isNestedTableMapping();
theOneThatsNotNull = mapping;
} else {
if (index != null) {
throw QueryException.indexRequiresCollectionMappingWithListOrderField(this, null);
}
}
if ((!shouldQueryToManyRelationship()) && qkIsToMany && (!isNestedMapping)) {
throw QueryException.invalidUseOfToManyQueryKeyInExpression(theOneThatsNotNull);
}
if (shouldQueryToManyRelationship() && !qkIsToMany) {
throw QueryException.invalidUseOfAnyOfInExpression(theOneThatsNotNull);
}
}
/**
* INTERNAL: Execute the query. If there are cached results return those. This must override the
* super to support result caching.
*
* @param session - the session in which the receiver will be executed.
* @return An object or vector, the result of executing the query.
* @exception DatabaseException - an error has occurred on the database
*/
public Object execute(AbstractSession session, AbstractRecord row) throws DatabaseException {
if (shouldCacheQueryResults()) {
if (getContainerPolicy().overridesRead()) {
throw QueryException.cannotCacheCursorResultsOnQuery(this);
}
if (shouldConformResultsInUnitOfWork()) {
throw QueryException.cannotConformAndCacheQueryResults(this);
}
if (isPrepared()) { // only prepared queries can have cached results.
Object queryResults = getQueryResults(session, row, true);
if (queryResults != null) {
if (QueryMonitor.shouldMonitor()) {
QueryMonitor.incrementReadAllHits(this);
}
// bug6138532 - check for "cached no results" (InvalidObject singleton) in query
// results, and return an empty container instance as configured
if (queryResults == InvalidObject.instance) {
return getContainerPolicy().containerInstance(0);
}
Collection results = (Collection) queryResults;
if (session.isUnitOfWork()) {
ContainerPolicy policy = getContainerPolicy();
Object resultCollection = policy.containerInstance(results.size());
Object iterator = policy.iteratorFor(results);
while (policy.hasNext(iterator)) {
Object result =
((UnitOfWorkImpl) session)
.registerExistingObject(policy.next(iterator, session), this.descriptor);
policy.addInto(result, resultCollection, session);
}
return resultCollection;
}
return results;
}
}
}
if (QueryMonitor.shouldMonitor()) {
QueryMonitor.incrementReadAllMisses(this);
}
return super.execute(session, row);
}
public QueryKey getQueryKeyOrNull() {
if (!hasQueryKey) {
return null;
}
// Oct 19, 2000 JED
// Added try/catch. This was throwing a NPE in the following case
// expresssionBuilder.get("firstName").get("bob")
// moved by Gordon Yorke to cover validate and normalize
if (getContainingDescriptor() == null) {
throw QueryException.invalidQueryKeyInExpression(getName());
}
if (queryKey == null) {
queryKey = getContainingDescriptor().getQueryKeyNamed(getName());
if (queryKey == null) {
hasQueryKey = false;
}
}
return queryKey;
}
/**
* INTERNAL This method iterates through a collection and gets the values from the objects to
* conform in an in-memory query. Creation date: (1/19/01 1:18:27 PM)
*/
public Object valuesFromCollection(
Object object, AbstractSession session, int valueHolderPolicy, boolean isObjectUnregistered) {
// in case the mapping is null - this can happen if a query key is being used
// In this case, check for the query key and find it's mapping.
boolean readMappingFromQueryKey = false;
if (getMapping() == null) {
getMappingFromQueryKey();
readMappingFromQueryKey = true;
}
// For bug 2780817 get the mapping directly from the object. In EJB 2.0
// inheritance, each child must override mappings defined in an abstract
// class with its own.
DatabaseMapping mapping = this.mapping;
ClassDescriptor descriptor = mapping.getDescriptor();
if (descriptor.hasInheritance() && (descriptor.getJavaClass() != object.getClass())) {
mapping =
session
.getDescriptor(object.getClass())
.getObjectBuilder()
.getMappingForAttributeName(getName());
descriptor = mapping.getDescriptor();
}
// fetch group support
if (descriptor.hasFetchGroupManager()) {
FetchGroupManager fetchGroupManager = descriptor.getFetchGroupManager();
if (fetchGroupManager.isPartialObject(object)
&& (!fetchGroupManager.isAttributeFetched(object, mapping.getAttributeName()))) {
// the conforming attribute is not fetched, simply throw exception
throw QueryException.cannotConformUnfetchedAttribute(mapping.getAttributeName());
}
}
if (mapping.isDirectToFieldMapping()) {
return ((AbstractDirectMapping) mapping).valueFromObject(object, mapping.getField(), session);
} else if (mapping.isForeignReferenceMapping()) {
// CR 3677 integration of a ValueHolderPolicy
Object valueFromMapping = mapping.getAttributeValueFromObject(object);
if (!((ForeignReferenceMapping) mapping)
.getIndirectionPolicy()
.objectIsInstantiated(valueFromMapping)) {
if (valueHolderPolicy != InMemoryQueryIndirectionPolicy.SHOULD_TRIGGER_INDIRECTION) {
// If the client wishes us to trigger the indirection then we should do so,
// Other wise throw the exception
throw QueryException
.mustInstantiateValueholders(); // you should instantiate the valueholder for this to
// work
}
// maybe we should throw this exception from the start, to save time
}
Object valueToIterate = mapping.getRealAttributeValueFromObject(object, session);
UnitOfWorkImpl uow = isObjectUnregistered ? (UnitOfWorkImpl) session : null;
// First check that object in fact is unregistered.
// toDo: ?? Why is this commented out? Why are we supporting the unregistered thing at all?
// Does not seem to be any public API for this, nor every used internally?
// if (isObjectUnregistered) {
// isObjectUnregistered = !uow.getCloneMapping().containsKey(object);
// }
if (mapping.isCollectionMapping() && (valueToIterate != null)) {
// For bug 2766379 must use the correct version of vectorFor to
// unwrap the result same time.
valueToIterate = mapping.getContainerPolicy().vectorFor(valueToIterate, session);
// toDo: If the value is empty, need to support correct inner/outer join filtering
// symantics.
// For CR 2612601, try to partially replace the result with already
// registered objects.
if (isObjectUnregistered && (uow.getCloneMapping().get(object) == null)) {
Vector objectValues = (Vector) valueToIterate;
for (int i = 0; i < objectValues.size(); i++) {
Object original = objectValues.elementAt(i);
Object clone =
uow.getIdentityMapAccessorInstance()
.getIdentityMapManager()
.getFromIdentityMap(original);
if (clone != null) {
objectValues.setElementAt(clone, i);
}
}
}
// For CR 2612601, conforming without registering, a query could be
// bob.get("address").get("city").equal("Ottawa"); where the address
// has been registered and modified in the UOW, but bob has not. Thus
// even though bob does not point to the modified address now, it will
// as soon as it is registered, so should point to it here.
} else if (isObjectUnregistered && (uow.getCloneMapping().get(object) == null)) {
Object clone =
uow.getIdentityMapAccessorInstance()
.getIdentityMapManager()
.getFromIdentityMap(valueToIterate);
if (clone != null) {
valueToIterate = clone;
}
}
return valueToIterate;
} else if (mapping.isAggregateMapping()) {
Object aggregateValue = mapping.getAttributeValueFromObject(object);
// Bug 3995468 - if this query key is to a mapping in an aggregate object, get the object from
// actual mapping rather than the aggregate mapping
while (readMappingFromQueryKey
&& mapping.isAggregateObjectMapping()
&& !((AggregateObjectMapping) mapping)
.getReferenceClass()
.equals(queryKey.getDescriptor().getJavaClass())) {
mapping =
mapping
.getReferenceDescriptor()
.getObjectBuilder()
.getMappingForField(((DirectQueryKey) queryKey).getField());
aggregateValue = mapping.getRealAttributeValueFromObject(aggregateValue, session);
}
return aggregateValue;
} else {
throw QueryException.cannotConformExpression();
}
}
/**
* PUBLIC: Specify the foreign-reference mapped attribute to be optimized in this query. The query
* will execute normally, however when any of the batched parts is accessed, the parts will all be
* read in a single query, this allows all of the data required for the parts to be read in a
* single query instead of (n) queries. This should be used when the application knows that it
* requires the part for all of the objects being read. This can be used for one-to-one,
* one-to-many, many-to-many and direct collection mappings.
*
* <p>The use of the expression allows for nested batch reading to be expressed.
*
* <p>Example: query.addBatchReadAttribute("phoneNumbers")
*
* @see #addBatchReadAttribute(Expression)
* @see ObjectLevelReadQuery#addJoinedAttribute(String)
*/
public void addBatchReadAttribute(String attributeName) {
if (!getQueryMechanism().isExpressionQueryMechanism()) {
throw QueryException.batchReadingNotSupported(this);
}
getBatchReadAttributeExpressions().add(getExpressionBuilder().get(attributeName));
}
/**
* INTERNAL: Possible for future development, not currently supported.
*
* <p>Retrieve the value through using batch reading. This executes a single query to read the
* target for all of the objects and stores the result of the batch query in the original query to
* allow the other objects to share the results.
*/
@Override
protected Object batchedValueFromRow(AbstractRecord row, ReadAllQuery query) {
throw QueryException.batchReadingNotSupported(this, query);
}