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
/*******************************************************************************
* 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.LAZY;
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: Java Persistence 1.0
/**
* Specifies a many-valued association with one-to-many multiplicity.
*
* <p> 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
* <code> mappedBy</code> element must be used to specify the relationship field or
* property of the entity that is the owner of the relationship.
*
* <p> The <code>OneToMany</code> 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
* <code> mappedBy</code> 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 <code>java.util.Map</code>, the <code>cascade</code>
* element and the <code>orphanRemoval</code> element apply to the map value.
*
* <pre>
*
* 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;}
*
* </pre>
*
* @since Java Persistence 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.
/**
* (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.
*
* <p> 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
java.util.Map, the cascade element applies to the
map value.
/**
* (Optional) The operations that must be cascaded to
* the target of the association.
* <p> Defaults to no operations being cascaded.
*
* <p> When the target collection is a {@link java.util.Map
* java.util.Map}, the <code>cascade</code> 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.
/** (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 LAZY;
The field that owns the relationship. Required unless
the relationship is unidirectional.
/**
* 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: Java Persistence 2.0
/**
* (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;
}