org.eclipse.persistence.internal.queries.CollectionContainerPolicy Maven / Gradle / Ivy
Show all versions of eclipselink Show documentation
/*
* Copyright (c) 1998, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.internal.queries;
import java.util.Collection;
import java.util.Vector;
import org.eclipse.persistence.exceptions.QueryException;
import org.eclipse.persistence.internal.helper.ClassConstants;
import org.eclipse.persistence.internal.helper.Helper;
import org.eclipse.persistence.internal.sessions.AbstractSession;
/**
* Purpose: A CollectionContainerPolicy is ContainerPolicy whose container class
* implements the Collection interface.
*
*
Responsibilities:
* Provide the functionality to operate on an instance of a Collection.
*
* @see ContainerPolicy
* @see MapContainerPolicy
*/
public class CollectionContainerPolicy extends InterfaceContainerPolicy {
/**
* INTERNAL:
* Construct a new policy.
*/
public CollectionContainerPolicy() {
super();
}
/**
* INTERNAL:
* Construct a new policy for the specified class.
*/
public CollectionContainerPolicy(Class containerClass) {
super(containerClass);
}
/**
* INTERNAL:
* Construct a new policy for the specified class name.
*/
public CollectionContainerPolicy(String containerClassName) {
super(containerClassName);
}
/**
* INTERNAL:
* Add element into a container which implements the Collection interface.
* @return boolean indicating whether the container changed.
*/
@Override
public boolean addInto(Object key, Object element, Object container, AbstractSession session) {
Object elementToAdd = element;
// PERF: Using direct access.
if (this.elementDescriptor != null) {
elementToAdd = this.elementDescriptor.getObjectBuilder().wrapObject(element, session);
}
try {
return ((Collection)container).add(elementToAdd);
} catch (ClassCastException ex1) {
throw QueryException.cannotAddElement(element, container, ex1);
} catch (IllegalArgumentException ex2) {
throw QueryException.cannotAddElement(element, container, ex2);
} catch (UnsupportedOperationException ex3) {
throw QueryException.cannotAddElement(element, container, ex3);
}
}
/**
* INTERNAL:
* Return a container populated with the contents of the specified Vector.
*/
@Override
public Object buildContainerFromVector(Vector vector, AbstractSession session) {
if ((getContainerClass() == vector.getClass()) && (!hasElementDescriptor())) {
return vector;
} else {
return super.buildContainerFromVector(vector, session);
}
}
/**
* INTERNAL:
* Remove all the elements from container.
*
* @param container java.lang.Object
*/
@Override
public void clear(Object container) {
try {
((Collection)container).clear();
} catch (UnsupportedOperationException ex) {
throw QueryException.methodNotValid(container, "clear()");
}
}
/**
* INTERNAL:
* Return a clone of the specified container.
*/
@Override
public Object cloneFor(Object container) {
if (container == null) {
return null;
}
if (container instanceof java.lang.Cloneable) {
return super.cloneFor(container);
}
Collection original = (Collection)container;
Collection clone = (Collection)containerInstance(original.size());
clone.addAll(original);
return clone;
}
/**
* INTERNAL:
* Return the true if element exists in container.
*
* @param element java.lang.Object
* @param container java.lang.Object
* @return boolean true if container 'contains' element
*/
@Override
protected boolean contains(Object element, Object container) {
return ((Collection)container).contains(element);
}
@Override
public Class getInterfaceType() {
return ClassConstants.Collection_Class;
}
/**
* INTERNAL:
* Return whether the collection has order.
* SortedSets cannot be indexed, but they are order-sensitive.
*/
@Override
public boolean hasOrder() {
return Helper.classImplementsInterface(this.getContainerClass(), ClassConstants.SortedSet_Class);
}
/**
* INTERNAL:
* Validate the container type.
*/
@Override
public boolean isValidContainer(Object container) {
// PERF: Use instanceof which is inlined, not isAssignable which is very inefficent.
return container instanceof Collection;
}
@Override
public boolean isCollectionPolicy() {
return true;
}
/**
* INTERNAL:
* Return an iterator for the given container.
*
* @param container java.lang.Object
* @return java.util.Enumeration/java.util.Iterator
*/
@Override
public Object iteratorFor(Object container) {
return ((Collection)container).iterator();
}
/**
* INTERNAL:
* Remove element from container which implements the Collection interface.
*
* @param key java.lang.Object This param represents the key that would be used by this object in a map, may be null
* @param element java.lang.Object
* @param container java.lang.Object
*/
@Override
protected boolean removeFrom(Object key, Object element, Object container) {
try {
return ((Collection)container).remove(element);
} catch (UnsupportedOperationException ex) {
throw QueryException.methodNotValid(element, "remove(Object element)");
}
}
/**
* INTERNAL:
* Return the size of container.
*
* @return int The size of the container.
*/
@Override
public int sizeFor(Object container) {
return ((Collection)container).size();
}
}