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.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import static javax.persistence.FetchType.LAZY;
Specifies a many-valued association with many-to-many multiplicity.
Every many-to-many association has two sides, the owning side
and the non-owning, or inverse, side. The join table is specified
on the owning side. If the association is bidirectional, either
side may be designated as the owning side. If the relationship is
bidirectional, the non-owning side must use the mappedBy element of
the ManyToMany annotation to specify the relationship field or
property of the owning side.
The join table for the relationship, if not defaulted, is
specified on the owning side.
The ManyToMany 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 and the entity containing the embeddable class is the
owner of the relationship, the non-owning side must use the
mappedBy element of the ManyToMany
annotation to specify the relationship field or property of the
embeddable class. The dot (".") notation syntax must be used in the
mappedBy 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.
Example 1:
// In Customer class:
@ManyToMany
@JoinTable(name="CUST_PHONES")
public Set<PhoneNumber> getPhones() { return phones; }
// In PhoneNumber class:
@ManyToMany(mappedBy="phones")
public Set<Customer> getCustomers() { return customers; }
Example 2:
// In Customer class:
@ManyToMany(targetEntity=com.acme.PhoneNumber.class)
public Set getPhones() { return phones; }
// In PhoneNumber class:
@ManyToMany(targetEntity=com.acme.Customer.class, mappedBy="phones")
public Set getCustomers() { return customers; }
Example 3:
// In Customer class:
@ManyToMany
@JoinTable(name="CUST_PHONE",
joinColumns=
@JoinColumn(name="CUST_ID", referencedColumnName="ID"),
inverseJoinColumns=
@JoinColumn(name="PHONE_ID", referencedColumnName="ID")
)
public Set<PhoneNumber> getPhones() { return phones; }
// In PhoneNumberClass:
@ManyToMany(mappedBy="phones")
public Set<Customer> getCustomers() { return customers; }
See Also: - JoinTable
Since: Java Persistence 1.0
/**
* Specifies a many-valued association with many-to-many multiplicity.
*
* <p> Every many-to-many association has two sides, the owning side
* and the non-owning, or inverse, side. The join table is specified
* on the owning side. If the association is bidirectional, either
* side may be designated as the owning side. If the relationship is
* bidirectional, the non-owning side must use the <code>mappedBy</code> element of
* the <code>ManyToMany</code> annotation to specify the relationship field or
* property of the owning side.
*
* <p> The join table for the relationship, if not defaulted, is
* specified on the owning side.
*
* <p> The <code>ManyToMany</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 and the entity containing the embeddable class is the
* owner of the relationship, the non-owning side must use the
* <code>mappedBy</code> element of the <code>ManyToMany</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:
*
* // In Customer class:
*
* @ManyToMany
* @JoinTable(name="CUST_PHONES")
* public Set<PhoneNumber> getPhones() { return phones; }
*
* // In PhoneNumber class:
*
* @ManyToMany(mappedBy="phones")
* public Set<Customer> getCustomers() { return customers; }
*
* Example 2:
*
* // In Customer class:
*
* @ManyToMany(targetEntity=com.acme.PhoneNumber.class)
* public Set getPhones() { return phones; }
*
* // In PhoneNumber class:
*
* @ManyToMany(targetEntity=com.acme.Customer.class, mappedBy="phones")
* public Set getCustomers() { return customers; }
*
* Example 3:
*
* // In Customer class:
*
* @ManyToMany
* @JoinTable(name="CUST_PHONE",
* joinColumns=
* @JoinColumn(name="CUST_ID", referencedColumnName="ID"),
* inverseJoinColumns=
* @JoinColumn(name="PHONE_ID", referencedColumnName="ID")
* )
* public Set<PhoneNumber> getPhones() { return phones; }
*
* // In PhoneNumberClass:
*
* @ManyToMany(mappedBy="phones")
* public Set<Customer> getCustomers() { return customers; }
* </pre>
*
* @see JoinTable
*
* @since Java Persistence 1.0
*/
@Target({METHOD, FIELD})
@Retention(RUNTIME)
public @interface ManyToMany {
(Optional) The entity class that is the target of the
association. Optional only if the collection-valued
relationship 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-valued
* relationship 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.
When the target collection is a
java.util.Map, the cascade element applies to the
map value.
Defaults to no operations being cascaded.
/**
* (Optional) The operations that must be cascaded to the target
* of the association.
*
* <p> When the target collection is a {@link java.util.Map
* java.util.Map}, the <code>cascade</code> element applies to the
* map value.
*
* <p> Defaults to no operations being 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 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 "";
}