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/*
 * Copyright (c) 2008, 2020 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 - 2.1
//     Linda DeMichiel - 2.0

package jakarta.persistence;

import java.lang.annotation.Target;
import java.lang.annotation.Retention;

import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * Specifies a many-valued association with one-to-many multiplicity.
 * 
 * 

If the collection is defined using generics to specify the * element type, the associated target entity type need not be * specified; otherwise the target entity class must be specified. * If the relationship is bidirectional, the * mappedBy element must be used to specify the relationship field or * property of the entity that is the owner of the relationship. * *

The OneToMany annotation may be used within an embeddable class * contained within an entity class to specify a relationship to a * collection of entities. If the relationship is bidirectional, the * mappedBy element must be used to specify the relationship field or * property of the entity that is the owner of the relationship. * * When the collection is a java.util.Map, the cascade * element and the orphanRemoval element apply to the map value. * *

 *
 *    Example 1: One-to-Many association using generics
 *
 *    // In Customer class:
 *
 *    @OneToMany(cascade=ALL, mappedBy="customer")
 *    public Set<Order> getOrders() { return orders; }
 *
 *    In Order class:
 *
 *    @ManyToOne
 *    @JoinColumn(name="CUST_ID", nullable=false)
 *    public Customer getCustomer() { return customer; }
 *
 *
 *    Example 2: One-to-Many association without using generics
 *
 *    // In Customer class:
 *
 *    @OneToMany(targetEntity=com.acme.Order.class, cascade=ALL,
 *                mappedBy="customer")
 *    public Set getOrders() { return orders; }
 *
 *    // In Order class:
 *
 *    @ManyToOne
 *    @JoinColumn(name="CUST_ID", nullable=false)
 *    public Customer getCustomer() { return customer; }
 *
 *
 *    Example 3: Unidirectional One-to-Many association using a foreign key mapping
 *
 *    // In Customer class:
 *
 *    @OneToMany(orphanRemoval=true)
 *    @JoinColumn(name="CUST_ID") // join column is in table for Order
 *    public Set<Order> getOrders() {return orders;}
 *    
 * 
* * @since 1.0 */ @Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface OneToMany { /** * (Optional) The entity class that is the target * of the association. Optional only if the collection * property is defined using Java generics. * Must be specified otherwise. * *

Defaults to the parameterized type of * the collection when defined using generics. */ Class targetEntity() default void.class; /** * (Optional) The operations that must be cascaded to * the target of the association. *

Defaults to no operations being cascaded. * *

When the target collection is a {@link java.util.Map * java.util.Map}, the cascade element applies to the * map value. */ 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 entities * must be eagerly fetched. The LAZY strategy is a hint to the * persistence provider runtime. */ FetchType fetch() default FetchType.LAZY; /** * The field that owns the relationship. Required unless * the relationship is unidirectional. */ 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 2.0 */ boolean orphanRemoval() default false; }





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