/******************************************************************************* | |
* Copyright (c) 1998, 2013 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 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.descriptors; | |
import java.io.Serializable; | |
import org.eclipse.persistence.exceptions.*; | |
import org.eclipse.persistence.internal.sessions.AbstractSession; | |
/** | |
* <p><b>Purpose</b>: The wrapper policy can be used to wrap all objects read from the database in another object. | |
* This allows for EclipseLink to utilize one version of the class for its purposes and allows for the | |
* application to deal with another version of the object. | |
* The wrapper policy is used for things such as EJB Entity Beans and is directly used by the | |
* TopLink for WebLogic product for EJB Container Managed Persistence. | |
* | |
* It is assumed that relationships must be through the wrapper objects. | |
* Object identity is not maintained on the wrapper objects, only the wrapped object. | |
*/ | |
public interface WrapperPolicy extends Serializable { | |
/** | |
* PUBLIC: | |
* Required: Lets the policy perform initialization. | |
* @param session the session to initialize against | |
*/ | |
void initialize(AbstractSession session) throws DescriptorException; | |
/** | |
* PUBLIC: | |
* Required: Return true if the wrapped value should be traversed. | |
* Normally the wrapped value is looked after independently, it is not required to be traversed. | |
*/ | |
boolean isTraversable(); | |
/** | |
* PUBLIC: | |
* Required: Return true if the object is already wrapped. | |
*/ | |
boolean isWrapped(Object object); | |
/** | |
* PUBLIC: | |
* Required: Set the descriptor. | |
* @param descriptor the descriptor for the object being wrapped | |
*/ | |
void setDescriptor(ClassDescriptor descriptor); | |
/** | |
* PUBLIC: | |
* Required: Unwrap the object to return the implementation that is meant to be used by EclipseLink. | |
* The object may already be unwrapped in which case the object should be returned. | |
* @param proxy the wrapped object | |
* @param session the session to unwrap into | |
*/ | |
Object unwrapObject(Object proxy, AbstractSession session); | |
/** | |
* PUBLIC: | |
* Required: Wrap the object to return the implementation that the application requires. | |
* The object may already be wrapped in which case the object should be returned. | |
* @param original, the object to be wrapped | |
* @param session the session to wrap the object against. | |
* @return java.lang.Object the wrapped object | |
*/ | |
Object wrapObject(Object original, AbstractSession session); | |
} |