/*
* Copyright (c) 2008, 2009 Sun Microsystems. 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:
* Linda DeMichiel - Java Persistence 2.0 - Version 2.0 (October 1, 2009)
* Specification available from http://jcp.org/en/jsr/detail?id=317
*/
// $Id: PersistenceUtil.java 17036 2009-07-08 09:09:38Z epbernard $
package javax.persistence;
/**
* Utility interface between the application and the persistence
* provider managing the persistence unit.
* <p/>
* <p>The methods of this interface should only be invoked on entity
* instances obtained from or managed by entity managers for this
* persistence unit or on new entity instances.
*
* @since Java Persistence 2.0
*/
public interface PersistenceUnitUtil extends PersistenceUtil {
/**
* Determine the load state of a given persistent attribute
* of an entity belonging to the persistence unit.
*
* @param entity entity instance containing the attribute
* @param attributeName name of attribute whose load state is
* to be determined
*
* @return false if entity's state has not been loaded or if
* the attribute state has not been loaded, else true
*/
public boolean isLoaded(Object entity, String attributeName);
/**
* Determine the load state of an entity belonging to the
* persistence unit. This method can be used to determine the
* load state of an entity passed as a reference. An entity is
* considered loaded if all attributes for which
* <code>FetchType.EAGER</code> has been specified have been
* loaded.
* <p> The <code>isLoaded(Object, String)</code> method
* should be used to determine the load state of an attribute.
* Not doing so might lead to unintended loading of state.
*
* @param entity entity instance whose load state is to be determined
*
* @return false if the entity has not been loaded, else true
*/
public boolean isLoaded(Object entity);
/**
* Return the id of the entity.
* A generated id is not guaranteed to be available until after
* the database insert has occurred.
* Returns null if the entity does not yet have an id.
*
* @param entity entity instance
*
* @return id of the entity
*
* @throws IllegalArgumentException if the object is found not
* to be an entity
*/
public Object getIdentifier(Object entity);
}