http://www.avaje.org/java8-parent/persistence-api: For open source java artifacts.
  • Rob Bygrave 
/*
 * Copyright (c) 2008, 2009, 2011 Oracle, Inc. 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.
 */
package javax.persistence;


Utility interface between the application and the persistence provider(s).


The PersistenceUtil interface instance obtained from the Persistence class is used to determine the load state of an entity or entity attribute regardless of which persistence provider in the environment created the entity. 
Since:Java Persistence 2.0
/**
 * Utility interface between the application and the persistence provider(s).
 * <p>
 * The <code>PersistenceUtil</code> interface instance obtained from the {@link Persistence} class is used to
 * determine the load state of an entity or entity attribute regardless of which persistence provider in the
 * environment created the entity.
 *
 * @since Java Persistence 2.0
 */
public interface PersistenceUtil {
  
Determine the load state of a given persistent attribute.

Params:
  • entity –        entity containing the attribute
  • attributeName – name of attribute whose load state is to be determined
Returns:false if entity's state has not been loaded or if the attribute state has not been loaded, else
true
/**
   * Determine the load state of a given persistent attribute.
   *
   * @param entity        entity 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. 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
FetchType.EAGER has been specified have been loaded.


The isLoaded(Object, String) method should be used to determine the load state of an
attribute. Not doing so might lead to unintended loading of state.

Params:
  • entity – whose load state is to be determined
Returns:false if the entity has not been loaded, else true
/**
   * Determine the load state of an entity. 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 whose load state is to be determined
   * @return false if the entity has not been loaded, else true
   */
  public boolean isLoaded(Object entity);
}