/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2004-2010 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package javax.xml.bind.annotation;
import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;
/**
* <p>
* Maps a JavaBean property to XML IDREF.
*
* <p>
* To preserve referential integrity of an object graph across XML
* serialization followed by a XML deserialization, requires an object
* reference to be marshalled by reference or containment
* appropriately. Annotations <tt>@XmlID</tt> and <tt>@XmlIDREF</tt>
* together allow a customized mapping of a JavaBean property's
* type by containment or reference.
*
* <p><b>Usage</b> </p>
* The <tt>@XmlIDREF</tt> annotation can be used with the following
* program elements:
* <ul>
* <li> a JavaBean property </li>
* <li> non static, non transient field </li>
* </ul>
*
* <p>See "Package Specification" in javax.xml.bind.package javadoc for
* additional common information.</p>
*
* <p> The usage is subject to the following constraints:
* <ul>
*
* <li> If the type of the field or property is a collection type,
* then the collection item type must contain a property or
* field annotated with <tt>@XmlID</tt>. </li>
* <li> If the field or property is single valued, then the type of
* the property or field must contain a property or field
* annotated with <tt>@XmlID</tt>.
* <p>Note: If the collection item type or the type of the
* property (for non collection type) is java.lang.Object, then
* the instance must contain a property/field annotated with
* <tt>@XmlID</tt> attribute.
* </li>
* <li> This annotation can be used with the following annotations:
* {@link XmlElement}, {@link XmlAttribute}, {@link XmlList},
* and {@link XmlElements}.</li>
*
* </ul>
* <p><b>Example:</b> Map a JavaBean property to <tt>xs:IDREF</tt>
* (i.e. by reference rather than by containment)</p>
* <pre>
*
* //EXAMPLE: Code fragment
* public class Shipping {
* @XmlIDREF public Customer getCustomer();
* public void setCustomer(Customer customer);
* ....
* }
*
* <!-- Example: XML Schema fragment -->
* <xs:complexType name="Shipping">
* <xs:complexContent>
* <xs:sequence>
* <xs:element name="customer" type="xs:IDREF"/>
* ....
* </xs:sequence>
* </xs:complexContent>
* </xs:complexType>
*
* </pre>
*
*
* <p><b>Example 2: </b> The following is a complete example of
* containment versus reference.
*
* <pre>
* // By default, Customer maps to complex type <tt>xs:Customer</tt>
* public class Customer {
*
* // map JavaBean property type to <tt>xs:ID</tt>
* @XmlID public String getCustomerID();
* public void setCustomerID(String id);
*
* // .... other properties not shown
* }
*
*
* // By default, Invoice maps to a complex type <tt>xs:Invoice</tt>
* public class Invoice {
*
* // map by reference
* @XmlIDREF public Customer getCustomer();
* public void setCustomer(Customer customer);
*
* // .... other properties not shown here
* }
*
* // By default, Shipping maps to complex type <tt>xs:Shipping</tt>
* public class Shipping {
*
* // map by reference
* @XmlIDREF public Customer getCustomer();
* public void setCustomer(Customer customer);
* }
*
* // at least one class must reference Customer by containment;
* // Customer instances won't be marshalled.
* @XmlElement(name="CustomerData")
* public class CustomerData {
* // map reference to Customer by containment by default.
* public Customer getCustomer();
*
* // maps reference to Shipping by containment by default.
* public Shipping getShipping();
*
* // maps reference to Invoice by containment by default.
* public Invoice getInvoice();
* }
*
* <!-- XML Schema mapping for above code frament -->
*
* <xs:complexType name="Invoice">
* <xs:complexContent>
* <xs:sequence>
* <xs:element name="customer" type="xs:IDREF"/>
* ....
* </xs:sequence>
* </xs:complexContent>
* </xs:complexType>
*
* <xs:complexType name="Shipping">
* <xs:complexContent>
* <xs:sequence>
* <xs:element name="customer" type="xs:IDREF"/>
* ....
* </xs:sequence>
* </xs:complexContent>
* </xs:complexType>
*
* <xs:complexType name="Customer">
* <xs:complexContent>
* <xs:sequence>
* ....
* </xs:sequence>
* <xs:attribute name="CustomerID" type="xs:ID"/>
* </xs:complexContent>
* </xs:complexType>
*
* <xs:complexType name="CustomerData">
* <xs:complexContent>
* <xs:sequence>
* <xs:element name="customer" type="xs:Customer"/>
* <xs:element name="shipping" type="xs:Shipping"/>
* <xs:element name="invoice" type="xs:Invoice"/>
* </xs:sequence>
* </xs:complexContent>
* </xs:complexType>
*
* <xs:element name"customerData" type="xs:CustomerData"/>
*
* <!-- Instance document conforming to the above XML Schema -->
* <customerData>
* <customer customerID="Alice">
* ....
* </customer>
*
* <shipping customer="Alice">
* ....
* </shipping>
*
* <invoice customer="Alice">
* ....
* </invoice>
* </customerData>
*
* </pre>
*
* <p><b>Example 3: </b> Mapping List to repeating element of type IDREF
* <pre>
* // Code fragment
* public class Shipping {
* @XmlIDREF
* @XmlElement(name="Alice")
* public List customers;
* }
*
* <!-- XML schema fragment -->
* <xs:complexType name="Shipping">
* <xs:sequence>
* <xs:choice minOccurs="0" maxOccurs="unbounded">
* <xs:element name="Alice" type="xs:IDREF"/>
* </xs:choice>
* </xs:sequence>
* </xs:complexType>
* </pre>
*
* <p><b>Example 4: </b> Mapping a List to a list of elements of type IDREF.
* <pre>
* //Code fragment
* public class Shipping {
* @XmlIDREF
* @XmlElements(
* @XmlElement(name="Alice", type="Customer.class")
* @XmlElement(name="John", type="InternationalCustomer.class")
* public List customers;
* }
*
* <!-- XML Schema fragment -->
* <xs:complexType name="Shipping">
* <xs:sequence>
* <xs:choice minOccurs="0" maxOccurs="unbounded">
* <xs:element name="Alice" type="xs:IDREF"/>
* <xs:element name="John" type="xs:IDREF"/>
* </xs:choice>
* </xs:sequence>
* </xs:complexType>
* </pre>
* @author Sekhar Vajjhala, Sun Microsystems, Inc.
* @see XmlID
* @since JAXB2.0
*/
@Retention(RUNTIME) @Target({FIELD, METHOD})
public @interface XmlIDREF {}
|