/*******************************************************************************
* Copyright (c) 1998, 2008 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.queries;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.eclipse.persistence.exceptions.QueryException;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.localization.ExceptionLocalization;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
import org.eclipse.persistence.internal.security.PrivilegedClassForName;
import org.eclipse.persistence.mappings.DatabaseMapping;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.mappings.OneToOneMapping;
import org.eclipse.persistence.sessions.DatabaseRecord;
/**
* <p><b>Purpose</b>:
* Concrete class to represent the EntityResult structure as defined by
* the EJB 3.0 Persistence specification. This class is a subcomponent of the
* SQLResultSetMapping
*
* @see SQLResultSetMapping
* @author Gordon Yorke
* @since TopLink Java Essentials
*/
public class EntityResult extends SQLResult {
/** Stores the class name of result */
protected String entityClassName;
protected Class entityClass;
/** Stores the list of FieldResult */
protected Map fieldResults;
/** Stores the column that will contain the value to determine the correct subclass
* to create if applicable.
*/
protected String discriminatorColumn;
public EntityResult(Class entityClass){
this.entityClass = entityClass;
if (this.entityClass == null){
throw new IllegalArgumentException(ExceptionLocalization.buildMessage("null_value_for_entity_result"));
}
}
public EntityResult(String entityClassName){
this.entityClassName = entityClassName;
if (this.entityClassName == null){
throw new IllegalArgumentException(ExceptionLocalization.buildMessage("null_value_for_entity_result"));
}
}
public void addFieldResult(FieldResult fieldResult){
if (fieldResult == null || fieldResult.getAttributeName() == null){
return;
}
FieldResult existingFieldResult = (FieldResult)getFieldResults().get(fieldResult.getAttributeName());
if (existingFieldResult==null){
getFieldResults().put(fieldResult.getAttributeName(), fieldResult);
}else{
existingFieldResult.add(fieldResult);
}
}
/**
* INTERNAL:
* Convert all the class-name-based settings in this query to actual class-based
* settings. This method is used when converting a project that has been built
* with class names to a project with classes.
* @param classLoader
*/
public void convertClassNamesToClasses(ClassLoader classLoader){
super.convertClassNamesToClasses(classLoader);
Class entityClass = null;
try{
if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){
try {
entityClass = (Class)AccessController.doPrivileged(new PrivilegedClassForName(entityClassName, true, classLoader));
} catch (PrivilegedActionException exception) {
throw ValidationException.classNotFoundWhileConvertingClassNames(entityClassName, exception.getException());
}
} else {
entityClass = org.eclipse.persistence.internal.security.PrivilegedAccessHelper.getClassForName(entityClassName, true, classLoader);
}
} catch (ClassNotFoundException exc){
throw ValidationException.classNotFoundWhileConvertingClassNames(entityClassName, exc);
}
this.entityClass = entityClass;
};
/**
* Accessor for the internally stored list of FieldResult. Calling this
* method will result in a collection being created to store the FieldResult
*/
public Map getFieldResults(){
if (this.fieldResults == null){
this.fieldResults = new HashMap();
}
return this.fieldResults;
}
/**
* Returns the column name for the column that will store the value used to
* determine the subclass type if applicable.
*/
public String getDiscriminatorColumn(){
return this.discriminatorColumn;
}
/**
* Sets the column name for the column that will store the value used to
* determine the subclass type if applicable.
*/
public void setDiscriminatorColumn(String column){
if (column == null){
return;
}
this.discriminatorColumn = column;
}
/**
* INTERNAL:
* This method is a convenience method for extracting values from Results
*/
public Object getValueFromRecord(DatabaseRecord record, ResultSetMappingQuery query){
// From the row data build result entity.
// To do this let's collect the column based data for this entity from
// the results and call build object with this new row.
ClassDescriptor descriptor = query.getSession().getDescriptor(this.entityClass);
DatabaseRecord entityRecord = new DatabaseRecord(descriptor.getFields().size());
if (descriptor.hasInheritance()) {
if (this.discriminatorColumn != null) {
Object value = record.get(this.discriminatorColumn);
if (value == null){
throw QueryException.discriminatorColumnNotSelected(this.discriminatorColumn, query.getSQLResultSetMapping().getName());
}
entityRecord.put(descriptor.getInheritancePolicy().getClassIndicatorField(), record.get(this.discriminatorColumn));
} else {
entityRecord.put(descriptor.getInheritancePolicy().getClassIndicatorField(), record.get(descriptor.getInheritancePolicy().getClassIndicatorField()));
}
// if the descriptor uses inheritance and multiple types may have been read
//get the correct descriptor.
if (descriptor.hasInheritance() && descriptor.getInheritancePolicy().shouldReadSubclasses()) {
Class classValue = descriptor.getInheritancePolicy().classFromRow(entityRecord, query.getSession());
descriptor = query.getSession().getDescriptor(classValue);
}
}
for (Iterator mappings = descriptor.getMappings().iterator(); mappings.hasNext();) {
DatabaseMapping mapping = (DatabaseMapping)mappings.next();
FieldResult fieldResult = (FieldResult)this.getFieldResults().get(mapping.getAttributeName());
if (fieldResult != null){
if (mapping.getFields().size() == 1 ) {
entityRecord.put(mapping.getFields().firstElement(), record.get(fieldResult.getColumnName()));
} else if (mapping.getFields().size() >1){
getValueFromRecordForMapping(entityRecord,mapping,fieldResult,record);
}
} else {
for (Iterator fields = mapping.getFields().iterator(); fields.hasNext();) {
DatabaseField field = (DatabaseField)fields.next();
entityRecord.put(field, record.get(field));
}
}
}
query.setReferenceClass(this.entityClass);
query.setDescriptor(descriptor);
return descriptor.getObjectBuilder().buildObject(query, entityRecord, null);
}
public boolean isEntityResult(){
return true;
}
/**
* INTERNAL:
* This method is for processing all FieldResults for a mapping. Adds DatabaseFields to the passed in entityRecord
*/
public void getValueFromRecordForMapping(DatabaseRecord entityRecord,DatabaseMapping mapping, FieldResult fieldResult, DatabaseRecord databaseRecord){
ClassDescriptor currentDescriptor = mapping.getReferenceDescriptor();
/** check if this FieldResult contains any other FieldResults, process it if it doesn't */
if (fieldResult.getFieldResults()==null){
DatabaseField dbfield = processValueFromRecordForMapping(currentDescriptor,fieldResult.getMultipleFieldIdentifiers(),1);
/** If it is a 1:1 mapping we need to do the target to source field conversion. If it is an aggregate, it is fine as it is*/
if (mapping.isOneToOneMapping()){
dbfield = (((OneToOneMapping)mapping).getTargetToSourceKeyFields().get(dbfield));
}
entityRecord.put(dbfield, databaseRecord.get(fieldResult.getColumnName()));
return;
}
/** This processes each FieldResult stored in the collection of FieldResults individually */
Iterator fieldResults = fieldResult.getFieldResults().iterator();
while (fieldResults.hasNext()){
FieldResult tempFieldResult = ((FieldResult)fieldResults.next());
DatabaseField dbfield = processValueFromRecordForMapping(currentDescriptor,tempFieldResult.getMultipleFieldIdentifiers(),1);
if (mapping.isOneToOneMapping()){
dbfield = (((OneToOneMapping)mapping).getTargetToSourceKeyFields().get(dbfield));
}
entityRecord.put(dbfield, databaseRecord.get(tempFieldResult.getColumnName()));
}
}
/**
* INTERNAL:
* This method is for processing a single FieldResult, returning the DatabaseField it refers to.
*/
public DatabaseField processValueFromRecordForMapping(ClassDescriptor descriptor, String[] attributeNames, int currentLoc){
DatabaseMapping mapping = descriptor.getObjectBuilder().getMappingForAttributeName(attributeNames[currentLoc]);
if (mapping==null){throw QueryException.mappingForFieldResultNotFound(attributeNames,currentLoc);}
currentLoc++;
if (attributeNames.length!=currentLoc){
ClassDescriptor currentDescriptor = mapping.getReferenceDescriptor();
DatabaseField df= processValueFromRecordForMapping(currentDescriptor, attributeNames, currentLoc);
if (mapping.isOneToOneMapping()){
return (((OneToOneMapping)mapping).getTargetToSourceKeyFields().get(df));
}
return df;
}else{
//this is it.. return this mapping's field
return mapping.getFields().firstElement();
}
}
}