src/javax/persistence/Inheritance.java

/*
 * Copyright (c) 2008, 2018 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:
//     Linda DeMichiel - Java Persistence 2.1
//     Linda DeMichiel - Java Persistence 2.0

package javax.persistence;

import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import static javax.persistence.InheritanceType.SINGLE_TABLE;

/**
 * Specifies the inheritance strategy to be used for an entity class
 * hierarchy. It is specified on the entity class that is the root of
 * the entity class hierarchy.  If the <code>Inheritance</code> annotation is not
 * specified or if no inheritance type is specified for an entity
 * class hierarchy, the <code>SINGLE_TABLE</code> mapping strategy is used.
 *
 * <pre>
 *
 *   Example:
 *
 *   &#064;Entity
 *   &#064;Inheritance(strategy=JOINED)
 *   public class Customer { ... }
 *
 *   &#064;Entity
 *   public class ValuedCustomer extends Customer { ... }
 * </pre>
 *
 * @since Java Persistence 1.0
 */
@Target({TYPE})
@Retention(RUNTIME)

public @interface Inheritance {

    /** The strategy to be used for the entity inheritance hierarchy. */
    InheritanceType strategy() default SINGLE_TABLE;
}