| /* |
| * 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: |
| // Petros Splinakis - Java Persistence 2.2 |
| // Linda DeMichiel - Java Persistence 2.1 |
| // Linda DeMichiel - Java Persistence 2.0 |
| |
| package javax.persistence; |
| |
| import java.lang.annotation.Repeatable; |
| import java.lang.annotation.Target; |
| import java.lang.annotation.Retention; |
| import static java.lang.annotation.ElementType.FIELD; |
| import static java.lang.annotation.ElementType.METHOD; |
| import static java.lang.annotation.RetentionPolicy.RUNTIME; |
| import static javax.persistence.ConstraintMode.PROVIDER_DEFAULT; |
| |
| /** |
| * Specifies a mapping to an entity that is a map key. The map key |
| * join column is in the collection table, join table, or table of the |
| * target entity that is used to represent the map. If no |
| * <code>MapKeyJoinColumn</code> annotation is specified, a single |
| * join column is assumed and the default values apply. |
| * |
| * <pre> |
| * |
| * Example 1: |
| * |
| * @Entity |
| * public class Company { |
| * @Id int id; |
| * ... |
| * @OneToMany // unidirectional |
| * @JoinTable(name="COMPANY_ORGANIZATION", |
| * joinColumns=@JoinColumn(name="COMPANY"), |
| * inverseJoinColumns=@JoinColumn(name="VICEPRESIDENT")) |
| * @MapKeyJoinColumn(name="DIVISION") |
| * Map<Division, VicePresident> organization; |
| * } |
| * |
| * Example 2: |
| * |
| * @Entity |
| * public class VideoStore { |
| * @Id int id; |
| * String name; |
| * Address location; |
| * ... |
| * @ElementCollection |
| * @CollectionTable(name="INVENTORY", |
| * joinColumns=@JoinColumn(name="STORE")) |
| * @Column(name="COPIES_IN_STOCK") |
| * @MapKeyJoinColumn(name="MOVIE", referencedColumnName="ID") |
| * Map<Movie, Integer> videoInventory; |
| * ... |
| * } |
| * |
| * @Entity |
| * public class Movie { |
| * @Id long id; |
| * String title; |
| * ... |
| * } |
| * |
| * Example 3: |
| * |
| * @Entity |
| * public class Student { |
| * @Id int studentId; |
| * ... |
| * @ManyToMany // students and courses are also many-many |
| * @JoinTable(name="ENROLLMENTS", |
| * joinColumns=@JoinColumn(name="STUDENT"), |
| * inverseJoinColumns=@JoinColumn(name="SEMESTER")) |
| * @MapKeyJoinColumn(name="COURSE") |
| * Map<Course, Semester> enrollment; |
| * ... |
| * } |
| * </pre> |
| * |
| * @see ForeignKey |
| * |
| * @since Java Persistence 2.0 |
| */ |
| @Repeatable(MapKeyJoinColumns.class) |
| @Target( { METHOD, FIELD }) |
| @Retention(RUNTIME) |
| public @interface MapKeyJoinColumn { |
| /** |
| * (Optional) The name of the foreign key column for the map |
| * key. The table in which it is found depends upon the |
| * context. |
| * <ul> |
| * <li> If the join is for a map key for an |
| * element collection, the foreign key column is in the |
| * collection table for the map value. |
| * <li> If the join is for a map key for a ManyToMany entity |
| * relationship or for a OneToMany entity relationship |
| * using a join table, the foreign key column is in a join table. |
| * <li> If the join is for a OneToMany entity relationship using |
| * a foreign key mapping strategy, the foreign key column for the |
| * map key is in the table of the entity that is the value of the map. |
| * </ul> |
| * |
| * <p> Default (only applies if a single join column is used.) |
| * The concatenation of the following: the name of the |
| * referencing relationship property or field of the |
| * referencing entity or embeddable class; "_"; "KEY". |
| */ |
| String name() default ""; |
| |
| /** |
| * (Optional) The name of the column referenced by this foreign key column. |
| * The referenced column is in the table of the target entity. |
| * |
| * <p> Default (only applies if single join column is being |
| * used.) The same name as the primary key column of the |
| * referenced table |
| */ |
| String referencedColumnName() default ""; |
| |
| /** |
| * (Optional) Whether the property is a unique key. This is a |
| * shortcut for the <code>UniqueConstraint</code> annotation |
| * at the table level and is useful for when the unique key |
| * constraint is only a single field. |
| */ |
| boolean unique() default false; |
| |
| /** |
| * (Optional) Whether the foreign key column is nullable. |
| */ |
| boolean nullable() default false; |
| |
| /** |
| * (Optional) Whether the column is included in SQL INSERT statements |
| * generated by the persistence provider. |
| */ |
| boolean insertable() default true; |
| |
| /** |
| * (Optional) Whether the column is included in SQL UPDATE statements |
| * generated by the persistence provider. |
| */ |
| boolean updatable() default true; |
| |
| /** |
| * (Optional) The SQL fragment that is used when generating the DDL for the |
| * column. |
| * Defaults to SQL generated by the provider for the column. |
| */ |
| String columnDefinition() default ""; |
| |
| /** |
| * (Optional) The name of the table that contains the foreign key column. |
| * <ul> |
| * <li> If the join is for a map key for an element collection, the foreign key |
| * column is in the collection table for the map value. |
| * <li> If the join is for a map key for a ManyToMany entity relationship |
| * or for a OneToMany entity relationship using a join table, |
| * the foreign key column is in a join table. |
| * <li> If the join is for a OneToMany entity relationship using a foreign |
| * key mapping strategy, the foreign key column for the map key is in the |
| * table of the entity that is the value of the map. |
| * </ul> |
| * <p> Default: |
| * <ul> |
| * <li> If the map is for an element collection, the |
| * name of the collection table for the map value. |
| * <li> If the map is for a OneToMany or ManyToMany entity relationship |
| * using a join table, the name of the join table for the map. |
| * <li> If the map is for a OneToMany entity relationship using a |
| * foreign key mapping strategy, the name of the primary table |
| * of the entity that is the value of the map. |
| * </ul> |
| */ |
| String table() default ""; |
| |
| /** |
| * (Optional) Used to specify or control the generation of a |
| * foreign key constraint when table generation is in effect. If |
| * this element is not specified, the persistence provider's |
| * default foreign key strategy will apply. |
| * |
| * @since Java Persistence 2.1 |
| */ |
| ForeignKey foreignKey() default @ForeignKey(PROVIDER_DEFAULT); |
| } |