/*******************************************************************************
* Copyright (c) 1998, 2009 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.security.AccessController;
import java.security.PrivilegedActionException;
import java.util.*;
import java.lang.reflect.*;
import org.eclipse.persistence.exceptions.*;
import org.eclipse.persistence.internal.helper.*;
import org.eclipse.persistence.queries.DatabaseQuery;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
import org.eclipse.persistence.internal.security.PrivilegedClassForName;
import org.eclipse.persistence.internal.security.PrivilegedMethodInvoker;
import org.eclipse.persistence.internal.security.PrivilegedGetValueFromField;
import org.eclipse.persistence.internal.sessions.CollectionChangeRecord;
import org.eclipse.persistence.internal.sessions.ObjectChangeSet;
import org.eclipse.persistence.internal.sessions.UnitOfWorkImpl;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.descriptors.changetracking.MapChangeEvent;
import org.eclipse.persistence.descriptors.changetracking.CollectionChangeEvent;
/**
* <p><b>Purpose</b>: A MapContainerPolicy is ContainerPolicy whose container class
* implements the Map interface.
* <p>
* <p><b>Responsibilities</b>:
* Provide the functionality to operate on an instance of a Map.
*
* @see ContainerPolicy
* @see CollectionContainerPolicy
*/
public class MapContainerPolicy extends InterfaceContainerPolicy {
/** The Method which is called on each value added to the Map and whose result is used as key to the value. */
protected String keyName;
protected String elementClassName;
protected Class elementClass;
protected transient Field keyField;
protected transient Method keyMethod;
/**
* INTERNAL:
* Construct a new policy.
*/
public MapContainerPolicy() {
super();
}
/**
* INTERNAL:
* Construct a new policy for the specified class.
*/
public MapContainerPolicy(Class containerClass) {
super(containerClass);
}
/**
* INTERNAL:
* Construct a new policy for the specified class name.
*/
public MapContainerPolicy(String containerClassName) {
super(containerClassName);
}
/**
* Prepare and validate.
* Set the element class.
*/
public void prepare(DatabaseQuery query, AbstractSession session) throws QueryException {
if ((getElementClass() == null) && (query.getDescriptor() != null)) {
setElementClass(query.getDescriptor().getJavaClass());
}
super.prepare(query, session);
}
/**
* INTERNAL:
* Add element into container which implements the Map interface.
*/
public boolean addInto(Object key, Object element, Object container, AbstractSession session) {
Object wrapped = element;
if (hasElementDescriptor()) {
wrapped = getElementDescriptor().getObjectBuilder().wrapObject(element, session);
}
try {
if (key != null) {
return ((Map)container).put(key, wrapped) != null;
} else {
Object keyFromElement = keyFrom(element, session);
try {
Object result = ((Map)container).put(keyFromElement, wrapped);
return null != result;
} catch (NullPointerException e) {
// If the container Map is a concrete type that does not
// allow null keys then throw a QueryException. Note, a
// HashMap permits null keys.
if (keyFromElement == null) {
// TreeMap, HashTable, SortedMap do not permit null keys
throw QueryException.mapKeyIsNull(element, container);
} else {
// We got a null pointer exception for some other reason
// so re-throw the exception.
throw e;
}
}
}
} catch (ClassCastException ex1) {
throw QueryException.mapKeyNotComparable(key, container);
}
}
/**
* INTERNAL:
* Remove all the elements from container.
*/
public void clear(Object container) {
try {
((Map)container).clear();
} catch (UnsupportedOperationException ex) {
throw QueryException.methodNotValid(container, "clear()");
}
}
/**
* 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
*/
public boolean compareKeys(Object sourceValue, AbstractSession session) {
if (((UnitOfWorkImpl)session).isClassReadOnly(sourceValue.getClass())) {
return true;
}
Object backUpVersion = ((UnitOfWorkImpl)session).getBackupClone(sourceValue, getElementDescriptor());
return (keyFrom(backUpVersion, session).equals(keyFrom(sourceValue, session)));
}
/**
* INTERNAL:
* Return the true if element exists in container.
* @return boolean true if container 'contains' element
*/
protected boolean contains(Object element, Object container) {
return ((Map)container).containsValue(element);
}
/**
* INTERNAL:
* Convert all the class-name-based settings in this ContainerPolicy 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);
if (elementClassName == null){
return;
}
try {
Class elementClass = null;
if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){
try {
elementClass = (Class)AccessController.doPrivileged(new PrivilegedClassForName(elementClassName, true, classLoader));
} catch (PrivilegedActionException exception) {
throw ValidationException.classNotFoundWhileConvertingClassNames(containerClassName, exception.getException());
}
} else {
elementClass = org.eclipse.persistence.internal.security.PrivilegedAccessHelper.getClassForName(elementClassName, true, classLoader);
}
setElementClass(elementClass);
} catch (ClassNotFoundException exc){
throw ValidationException.classNotFoundWhileConvertingClassNames(containerClassName, exc);
}
}
/**
* INTERNAL:
* Returns the element class which defines the map key.
*/
public Class getElementClass() {
return elementClass;
}
/**
* INTERNAL:
* Returns the element class name which defines the map key.
*/
public String getElementClassName() {
return elementClassName;
}
/**
* INTERNAL:
*/
public Class getInterfaceType() {
return ClassConstants.Map_Class;
}
/**
* INTERNAL:
* Returns the key name which will return the value of the key to be used
* in the container.
*/
public String getKeyName() {
return keyName;
}
/**
* INTERNAL
* Yes this is a MapPolicy
*/
public boolean isMapPolicy() {
return true;
}
/**
* INTERNAL:
* Return an Iterator for the given container.
*/
public Object iteratorFor(Object container) {
return ((Map)container).values().iterator();
}
/**
* INTERNAL:
* Return the key for the specified element.
*/
public Object keyFrom(Object element, AbstractSession session) {
// Should only run through this once ...
if (keyName != null && keyMethod == null && keyField == null) {
try {
keyMethod = Helper.getDeclaredMethod(elementClass, keyName, (Class[]) null);
} catch (NoSuchMethodException ex) {
try {
keyField = Helper.getField(elementClass, keyName);
} catch (NoSuchFieldException e) {
throw ValidationException.mapKeyNotDeclaredInItemClass(keyName, elementClass);
}
}
}
Object keyElement = element;
if (hasElementDescriptor()) {
keyElement = getElementDescriptor().getObjectBuilder().unwrapObject(element, session);
}
if (keyMethod != null) {
try {
if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){
try {
return AccessController.doPrivileged(new PrivilegedMethodInvoker(keyMethod, keyElement, (Object[])null));
} catch (PrivilegedActionException exception) {
Exception throwableException = exception.getException();
if (throwableException instanceof IllegalAccessException) {
throw QueryException.cannotAccessMethodOnObject(keyMethod, keyElement);
} else {
throw QueryException.calledMethodThrewException(keyMethod, keyElement, throwableException);
}
}
} else {
return PrivilegedAccessHelper.invokeMethod(keyMethod, keyElement, (Object[])null);
}
} catch (IllegalAccessException e) {
throw QueryException.cannotAccessMethodOnObject(keyMethod, keyElement);
} catch (InvocationTargetException exception) {
throw QueryException.calledMethodThrewException(keyMethod, keyElement, exception);
}
} else if (keyField != null) {
try {
if (PrivilegedAccessHelper.shouldUsePrivilegedAccess()){
try {
return AccessController.doPrivileged(new PrivilegedGetValueFromField(keyField, keyElement));
} catch (PrivilegedActionException exception) {
throw QueryException.cannotAccessFieldOnObject(keyField, keyElement);
}
} else {
return org.eclipse.persistence.internal.security.PrivilegedAccessHelper.getValueFromField(keyField, keyElement);
}
} catch (IllegalAccessException e) {
throw QueryException.cannotAccessFieldOnObject(keyField, keyElement);
}
} else {
// If we get this far I think it is safe to assume we have
// an element descriptor.
return getElementDescriptor().getCMPPolicy().createPrimaryKeyInstance(keyElement, session);
}
}
/**
* 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){
Object key = null;
//This is to allow non-MapChangeEvent. Not sure how one could get here, but wasn't willing to remove the chance that it could
if (event.getClass().equals(ClassConstants.MapChangeEvent_Class)){
key = ((MapChangeEvent)event).getKey();
}
if (event.getChangeType() == CollectionChangeEvent.ADD) {
recordAddToCollectionInChangeRecord(changeSet, collectionChangeRecord);
changeSet.setNewKey(key);
} else if (event.getChangeType() == MapChangeEvent.REMOVE) {
recordRemoveFromCollectionInChangeRecord(changeSet, collectionChangeRecord);
changeSet.setOldKey(key);
} else {
throw ValidationException.wrongCollectionChangeEventType(event.getChangeType());
}
}
/**
* INTERNAL:
* Remove element from container which implements the Map interface.
*/
public boolean removeFrom(Object key, Object element, Object container, AbstractSession session) {
try {
Object returnValue = null;
if (key != null) {
returnValue = ((Map)container).remove(key);
} else if (element != null) {
returnValue = ((Map)container).remove(keyFrom(element, session));
}
if (returnValue == null) {
return false;
} else {
return true;
}
} catch (UnsupportedOperationException ex) {
throw QueryException.methodNotValid(container, "remove(Object element)");
}
}
/**
* INTERNAL:
* Remove element from container which implements the Map interface.
*/
public boolean removeFromWithIdentity(Object element, Object container, AbstractSession session) {
boolean found = false;
Vector knownKeys = new Vector(1);
try {
Iterator iterator = ((Map)container).keySet().iterator();
while (iterator.hasNext()) {
Object key = iterator.next();
if (((Map)container).get(key) == element) {
knownKeys.addElement(key);
found = true;
}
}
if (found) {
for (int index = 0; index < knownKeys.size(); ++index) {
((Map)container).remove(knownKeys.elementAt(index));
}
}
return found;
} catch (UnsupportedOperationException ex) {
throw QueryException.methodNotValid(container, "remove(Object element)");
}
}
/**
* INTERNAL:
* Sets the element class which defines the method.
*/
public void setElementClass(Class elementClass) {
if (elementClass != null) {
elementClassName = elementClass.getName();
}
this.elementClass = elementClass;
}
/**
* INTERNAL:
* Validate the container type.
*/
public boolean isValidContainer(Object container) {
// PERF: Use instanceof which is inlined, not isAssignable which is very inefficent.
return container instanceof Map;
}
/**
* 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.
*/
public void setKeyName(String keyName, String elementClassName) {
// The key name and class name must be held as the policy is used
// directly from the mapping.
this.keyName = keyName;
this.elementClassName = elementClassName;
}
/**
* 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 keyName, Class elementClass) {
// The key name and class name must be held as the policy is used
// directly from the mapping.
this.keyName = keyName;
this.elementClass = elementClass;
}
/**
* INTERNAL:
* Sets the key name to be used to generate the key in a Map type container
* class. The key name, maybe the name of a field or method.
*/
public void setKeyName(String keyName) {
this.keyName = keyName;
}
/**
* INTERNAL:
* Sets the Method to be used to generate the key in a Map type container class.
*/
public void setKeyMethod(String keyMethodName, Class elementClass) {
this.setKeyName(keyMethodName, elementClass);
}
/**
* INTERNAL:
* Sets the Method to be used to generate the key in a Map type container class.
*/
public void setKeyMethod(String keyMethodName, String elementClassName) {
this.setKeyName(keyMethodName, elementClassName);
}
/**
* INTERNAL:
* Sets the Method to be used to generate the key in a Map type container class.
*/
public void setKeyMethodName(String keyMethodName) {
this.setKeyName(keyMethodName);
}
/**
* INTERNAL:
* Return the size of container.
*/
public int sizeFor(Object container) {
return ((Map)container).size();
}
/**
* INTERNAL:
* If the key has changed, remove the element and add it back into the target.
*/
public void validateElementAndRehashIfRequired(Object sourceValue, Object targetMap, AbstractSession session, Object targetVersionOfSource) {
if (session.isUnitOfWork()) {
//this must be a unit of work at this point
Object backupValue = ((UnitOfWorkImpl)session).getBackupClone(sourceValue, getElementDescriptor());
if (!keyFrom(backupValue, session).equals(keyFrom(sourceValue, session))) {
//the key has been changed. Remove the old value and put back the new one
removeFrom(backupValue, targetMap, session);
addInto(targetVersionOfSource, targetMap, session);
}
}
}
}