src/javax/persistence/metamodel/IdentifiableType.java

/*******************************************************************************
 * Copyright (c) 2008 - 2012 Oracle Corporation. 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 2.1
 *     Linda DeMichiel - Java Persistence 2.0
 *
 ******************************************************************************/ 
package javax.persistence.metamodel;

import java.util.Set;

/**
 *  Instances of the type <code>IdentifiableType</code> represent entity or 
 *  mapped superclass types.
 *
 *  @param <X> The represented entity or mapped superclass type.
 *
 *  @since Java Persistence 2.0
 *
 */
public interface IdentifiableType<X> extends ManagedType<X> {
	
    /**
     *  Return the attribute that corresponds to the id attribute of 
     *  the entity or mapped superclass.
     *  @param type  the type of the represented id attribute
     *  @return id attribute
     *  @throws IllegalArgumentException if id attribute of the given
     *          type is not present in the identifiable type or if
     *          the identifiable type has an id class
     */
    <Y> SingularAttribute<? super X, Y> getId(Class<Y> type);

    /**
     *  Return the attribute that corresponds to the id attribute 
     *  declared by the entity or mapped superclass.
     *  @param type  the type of the represented declared 
     *               id attribute
     *  @return declared id attribute
     *  @throws IllegalArgumentException if id attribute of the given
     *          type is not declared in the identifiable type or if
     *          the identifiable type has an id class
     */
    <Y> SingularAttribute<X, Y> getDeclaredId(Class<Y> type);

    /**
     *  Return the attribute that corresponds to the version 
     *  attribute of the entity or mapped superclass.
     *  @param type  the type of the represented version attribute
     *  @return version attribute
     *  @throws IllegalArgumentException if version attribute of the 
     * 	        given type is not present in the identifiable type
     */
    <Y> SingularAttribute<? super X, Y> getVersion(Class<Y> type);

    /**
     *  Return the attribute that corresponds to the version 
     *  attribute declared by the entity or mapped superclass.
     *  @param type  the type of the represented declared version 
     *               attribute
     *  @return declared version attribute
     *  @throws IllegalArgumentException if version attribute of the 
     *          type is not declared in the identifiable type
     */
    <Y> SingularAttribute<X, Y> getDeclaredVersion(Class<Y> type);
	
    /**
     *  Return the identifiable type that corresponds to the most
     *  specific mapped superclass or entity extended by the entity 
     *  or mapped superclass. 
     *  @return supertype of identifiable type or null if no 
     *          such supertype
     */
    IdentifiableType<? super X> getSupertype();

    /**
     *  Whether the identifiable type has a single id attribute.
     *  Returns true for a simple id or embedded id; returns false
     *  for an idclass.
     *  @return boolean indicating whether the identifiable
     *          type has a single id attribute
     */
    boolean hasSingleIdAttribute();

    /**
     *  Whether the identifiable type has a version attribute.
     *  @return boolean indicating whether the identifiable
     *          type has a version attribute
     */
    boolean hasVersionAttribute();

    /**
     *   Return the attributes corresponding to the id class of the
     *   identifiable type.
     *   @return id attributes
     *   @throws IllegalArgumentException if the identifiable type
     *           does not have an id class
     */
     Set<SingularAttribute<? super X, ?>> getIdClassAttributes();

    /**
     *  Return the type that represents the type of the id.
     *  @return type of id
     */
    Type<?> getIdType();
}