| /******************************************************************************* |
| * Copyright (c) 2008 - 2013 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; |
| |
| import java.lang.annotation.Target; |
| import java.lang.annotation.Retention; |
| import javax.persistence.CascadeType; |
| import static java.lang.annotation.ElementType.METHOD; |
| import static java.lang.annotation.ElementType.FIELD; |
| import static java.lang.annotation.RetentionPolicy.RUNTIME; |
| import static javax.persistence.FetchType.EAGER; |
| |
| /** |
| * Specifies a single-valued association to another entity that has |
| * one-to-one multiplicity. It is not normally necessary to specify |
| * the associated target entity explicitly since it can usually be |
| * inferred from the type of the object being referenced. If the relationship is |
| * bidirectional, the non-owning side must use the <code>mappedBy</code> element of |
| * the <code>OneToOne</code> annotation to specify the relationship field or |
| * property of the owning side. |
| * |
| * <p> The <code>OneToOne</code> annotation may be used within an |
| * embeddable class to specify a relationship from the embeddable |
| * class to an entity class. If the relationship is bidirectional and |
| * the entity containing the embeddable class is on the owning side of |
| * the relationship, the non-owning side must use the |
| * <code>mappedBy</code> element of the <code>OneToOne</code> |
| * annotation to specify the relationship field or property of the |
| * embeddable class. The dot (".") notation syntax must be used in the |
| * <code>mappedBy</code> element to indicate the relationship attribute within the |
| * embedded attribute. The value of each identifier used with the dot |
| * notation is the name of the respective embedded field or property. |
| * |
| * <pre> |
| * Example 1: One-to-one association that maps a foreign key column |
| * |
| * // On Customer class: |
| * |
| * @OneToOne(optional=false) |
| * @JoinColumn( |
| * name="CUSTREC_ID", unique=true, nullable=false, updatable=false) |
| * public CustomerRecord getCustomerRecord() { return customerRecord; } |
| * |
| * // On CustomerRecord class: |
| * |
| * @OneToOne(optional=false, mappedBy="customerRecord") |
| * public Customer getCustomer() { return customer; } |
| * |
| * |
| * Example 2: One-to-one association that assumes both the source and target share the same primary key values. |
| * |
| * // On Employee class: |
| * |
| * @Entity |
| * public class Employee { |
| * @Id Integer id; |
| * |
| * @OneToOne @MapsId |
| * EmployeeInfo info; |
| * ... |
| * } |
| * |
| * // On EmployeeInfo class: |
| * |
| * @Entity |
| * public class EmployeeInfo { |
| * @Id Integer id; |
| * ... |
| * } |
| * |
| * |
| * Example 3: One-to-one association from an embeddable class to another entity. |
| * |
| * @Entity |
| * public class Employee { |
| * @Id int id; |
| * @Embedded LocationDetails location; |
| * ... |
| * } |
| * |
| * @Embeddable |
| * public class LocationDetails { |
| * int officeNumber; |
| * @OneToOne ParkingSpot parkingSpot; |
| * ... |
| * } |
| * |
| * @Entity |
| * public class ParkingSpot { |
| * @Id int id; |
| * String garage; |
| * @OneToOne(mappedBy="location.parkingSpot") Employee assignedTo; |
| * ... |
| * } |
| * |
| * </pre> |
| * |
| * @since Java Persistence 1.0 |
| */ |
| @Target({METHOD, FIELD}) |
| @Retention(RUNTIME) |
| |
| public @interface OneToOne { |
| |
| /** |
| * (Optional) The entity class that is the target of |
| * the association. |
| * |
| * <p> Defaults to the type of the field or property |
| * that stores the association. |
| */ |
| Class targetEntity() default void.class; |
| |
| /** |
| * (Optional) The operations that must be cascaded to |
| * the target of the association. |
| * |
| * <p> By default no operations are cascaded. |
| */ |
| CascadeType[] cascade() default {}; |
| |
| /** |
| * (Optional) Whether the association should be lazily |
| * loaded or must be eagerly fetched. The EAGER |
| * strategy is a requirement on the persistence provider runtime that |
| * the associated entity must be eagerly fetched. The LAZY |
| * strategy is a hint to the persistence provider runtime. |
| */ |
| FetchType fetch() default EAGER; |
| |
| /** |
| * (Optional) Whether the association is optional. If set |
| * to false then a non-null relationship must always exist. |
| */ |
| boolean optional() default true; |
| |
| /** (Optional) The field that owns the relationship. This |
| * element is only specified on the inverse (non-owning) |
| * side of the association. |
| */ |
| String mappedBy() default ""; |
| |
| |
| /** |
| * (Optional) Whether to apply the remove operation to entities that have |
| * been removed from the relationship and to cascade the remove operation to |
| * those entities. |
| * @since Java Persistence 2.0 |
| */ |
| boolean orphanRemoval() default false; |
| } |