| /* |
| * 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; |
| |
| /** |
| * Specifies the value of the discriminator column for |
| * entities of the given type. |
| * |
| * <p> The <code>DiscriminatorValue</code> |
| * annotation can only be specified on a concrete entity |
| * class. |
| * |
| * <p> If the <code>DiscriminatorValue</code> annotation is not |
| * specified and a discriminator column is used, a provider-specific |
| * function will be used to generate a value representing the |
| * entity type. If the {@link DiscriminatorType} is <code> |
| * STRING</code>, the discriminator value |
| * default is the entity name. |
| * |
| * <p> The inheritance strategy and the discriminator column |
| * are only specified in the root of an entity class hierarchy |
| * or subhierarchy in which a different inheritance strategy is |
| * applied. The discriminator value, if not defaulted, should be |
| * specified for each entity class in the hierarchy. |
| * |
| * <pre> |
| * |
| * Example: |
| * |
| * @Entity |
| * @Table(name="CUST") |
| * @Inheritance(strategy=SINGLE_TABLE) |
| * @DiscriminatorColumn(name="DISC", discriminatorType=STRING, length=20) |
| * @DiscriminatorValue("CUSTOMER") |
| * public class Customer { ... } |
| * |
| * @Entity |
| * @DiscriminatorValue("VCUSTOMER") |
| * public class ValuedCustomer extends Customer { ... } |
| * </pre> |
| * |
| * @see DiscriminatorColumn |
| * |
| * @since Java Persistence 1.0 |
| */ |
| @Target({TYPE}) |
| @Retention(RUNTIME) |
| |
| public @interface DiscriminatorValue { |
| |
| /** |
| * (Optional) The value that indicates that the |
| * row is an entity of the annotated entity type. |
| * |
| * <p> If the <code>DiscriminatorValue</code> annotation is not |
| * specified and a discriminator column is used, a |
| * provider-specific function will be used to generate a value |
| * representing the entity type. If the <code>DiscriminatorType</code> is |
| * <code>STRING</code>, the discriminator value default is the |
| * entity name. |
| */ |
| String value(); |
| } |