/*
* Copyright (c) 2004, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
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.*;
Maps a JavaBean property to XML IDREF.
To preserve referential integrity of an object graph across XML serialization followed by a XML deserialization, requires an object reference to be marshaled by reference or containment appropriately. Annotations @XmlID
and @XmlIDREF
together allow a customized mapping of a JavaBean property's type by containment or reference.
Usage
The @XmlIDREF
annotation can be used with the following program elements:
- a JavaBean property
- non static, non transient field
See "Package Specification" in javax.xml.bind.package javadoc for
additional common information.
The usage is subject to the following constraints:
- 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
@XmlID
.
- If the field or property is single valued, then the type of the property or field must contain a property or field annotated with
@XmlID
. 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 @XmlID
attribute.
- This annotation can be used with the following annotations:
XmlElement
, XmlAttribute
, XmlList
, and XmlElements
.
Example: Map a JavaBean property to xs:IDREF
(i.e. by reference rather than by containment)
//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>
Example 2: The following is a complete example of
containment versus reference.
// By default, Customer maps to complex type xs:Customer
public class Customer { // map JavaBean property type to xs:ID
@XmlID public String getCustomerID(); public void setCustomerID(String id); // .... other properties not shown } // By default, Invoice maps to a complex type xs:Invoice
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 xs:Shipping
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>
Example 3: Mapping List to repeating element of type IDREF
// 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>
Example 4: Mapping a List to a list of elements of type IDREF.
//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>
Author: Sekhar Vajjhala, Sun Microsystems, Inc. See Also: Since: 1.6, JAXB 2.0
/**
* <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 marshaled by reference or containment
* appropriately. Annotations {@code @XmlID} and {@code @XmlIDREF}
* together allow a customized mapping of a JavaBean property's
* type by containment or reference.
*
* <p><b>Usage</b> </p>
* The {@code @XmlIDREF} 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 {@code @XmlID}. </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 {@code @XmlID}.
* <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
* {@code @XmlID} 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 {@code xs:IDREF}
* (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);
* ....
* }
* {@code
*
* <!-- 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 {@code xs:Customer}
* public class Customer {
*
* // map JavaBean property type to {@code xs:ID}
* @XmlID public String getCustomerID();
* public void setCustomerID(String id);
*
* // .... other properties not shown
* }
*
*
* // By default, Invoice maps to a complex type {@code xs:Invoice}
* 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 {@code xs:Shipping}
* 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();
* }
* {@code
*
* <!-- 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;
* }
* {@code
*
* <!-- 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;
* }
* {@code
*
* <!-- 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 1.6, JAXB 2.0
*/
@Retention(RUNTIME) @Target({FIELD, METHOD})
public @interface XmlIDREF {}