aoqi@0: /*
aoqi@0:  * Copyright (c) 2004, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: package javax.xml.bind.annotation;
aoqi@0: 
aoqi@0: import java.lang.annotation.Target;
aoqi@0: import java.lang.annotation.Retention;
aoqi@0: import static java.lang.annotation.ElementType.*;
aoqi@0: import static java.lang.annotation.RetentionPolicy.*;
aoqi@0: 
aoqi@0: /**
aoqi@0:  * <p>
aoqi@0:  * Maps a JavaBean property to XML IDREF.
aoqi@0:  *
aoqi@0:  * <p>
aoqi@0:  * To preserve referential integrity of an object graph across XML
aoqi@0:  * serialization followed by a XML deserialization, requires an object
aoqi@0:  * reference to be marshalled by reference or containment
aoqi@0:  * appropriately. Annotations <tt>&#64;XmlID</tt> and <tt>&#64;XmlIDREF</tt>
aoqi@0:  * together allow a customized mapping of a JavaBean property's
aoqi@0:  * type by containment or reference.
aoqi@0:  *
aoqi@0:  * <p><b>Usage</b> </p>
aoqi@0:  * The <tt>&#64;XmlIDREF</tt> annotation can be used with the following
aoqi@0:  * program elements:
aoqi@0:  * <ul>
aoqi@0:  *   <li> a JavaBean property </li>
aoqi@0:  *   <li> non static, non transient field </li>
aoqi@0:  * </ul>
aoqi@0:  *
aoqi@0:  * <p>See "Package Specification" in javax.xml.bind.package javadoc for
aoqi@0:  * additional common information.</p>
aoqi@0:  *
aoqi@0:  * <p> The usage is subject to the following constraints:
aoqi@0:  * <ul>
aoqi@0:  *
aoqi@0:  *   <li> If the type of the field or property is a collection type,
aoqi@0:  *        then the collection item type must contain a property or
aoqi@0:  *        field annotated with <tt>&#64;XmlID</tt>.  </li>
aoqi@0:  *   <li> If the field or property is single valued, then the type of
aoqi@0:  *        the property or field must contain a property or field
aoqi@0:  *        annotated with <tt>&#64;XmlID</tt>.
aoqi@0:  *        <p>Note: If the collection item type or the type of the
aoqi@0:  *        property (for non collection type) is java.lang.Object, then
aoqi@0:  *        the instance must contain a property/field annotated with
aoqi@0:  *        <tt>&#64;XmlID</tt> attribute.
aoqi@0:  *        </li>
aoqi@0:  *   <li> This annotation can be used with the following annotations:
aoqi@0:  *        {@link XmlElement}, {@link XmlAttribute}, {@link XmlList},
aoqi@0:  *        and {@link XmlElements}.</li>
aoqi@0:  *
aoqi@0:  * </ul>
aoqi@0:  * <p><b>Example:</b> Map a JavaBean property to <tt>xs:IDREF</tt>
aoqi@0:  *   (i.e. by reference rather than by containment)</p>
aoqi@0:  * <pre>
aoqi@0:  *
aoqi@0:  *   //EXAMPLE: Code fragment
aoqi@0:  *   public class Shipping {
aoqi@0:  *       &#64;XmlIDREF public Customer getCustomer();
aoqi@0:  *       public void setCustomer(Customer customer);
aoqi@0:  *       ....
aoqi@0:  *    }
aoqi@0:  *
aoqi@0:  *   &lt;!-- Example: XML Schema fragment -->
aoqi@0:  *   &lt;xs:complexType name="Shipping">
aoqi@0:  *     &lt;xs:complexContent>
aoqi@0:  *       &lt;xs:sequence>
aoqi@0:  *         &lt;xs:element name="customer" type="xs:IDREF"/>
aoqi@0:  *         ....
aoqi@0:  *       &lt;/xs:sequence>
aoqi@0:  *     &lt;/xs:complexContent>
aoqi@0:  *   &lt;/xs:complexType>
aoqi@0:  *
aoqi@0:  * </pre>
aoqi@0:  *
aoqi@0:  *
aoqi@0:  * <p><b>Example 2: </b> The following is a complete example of
aoqi@0:  * containment versus reference.
aoqi@0:  *
aoqi@0:  * <pre>
aoqi@0:  *    // By default, Customer maps to complex type <tt>xs:Customer</tt>
aoqi@0:  *    public class Customer {
aoqi@0:  *
aoqi@0:  *        // map JavaBean property type to <tt>xs:ID</tt>
aoqi@0:  *        &#64;XmlID public String getCustomerID();
aoqi@0:  *        public void setCustomerID(String id);
aoqi@0:  *
aoqi@0:  *        // .... other properties not shown
aoqi@0:  *    }
aoqi@0:  *
aoqi@0:  *
aoqi@0:  *   // By default, Invoice maps to a complex type <tt>xs:Invoice</tt>
aoqi@0:  *   public class Invoice {
aoqi@0:  *
aoqi@0:  *       // map by reference
aoqi@0:  *       &#64;XmlIDREF public Customer getCustomer();
aoqi@0:  *       public void setCustomer(Customer customer);
aoqi@0:  *
aoqi@0:  *      // .... other properties not shown here
aoqi@0:  *   }
aoqi@0:  *
aoqi@0:  *   // By default, Shipping maps to complex type <tt>xs:Shipping</tt>
aoqi@0:  *   public class Shipping {
aoqi@0:  *
aoqi@0:  *       // map by reference
aoqi@0:  *       &#64;XmlIDREF public Customer getCustomer();
aoqi@0:  *       public void setCustomer(Customer customer);
aoqi@0:  *   }
aoqi@0:  *
aoqi@0:  *   // at least one class must reference Customer by containment;
aoqi@0:  *   // Customer instances won't be marshalled.
aoqi@0:  *   &#64;XmlElement(name="CustomerData")
aoqi@0:  *   public class CustomerData {
aoqi@0:  *       // map reference to Customer by containment by default.
aoqi@0:  *       public Customer getCustomer();
aoqi@0:  *
aoqi@0:  *       // maps reference to Shipping by containment by default.
aoqi@0:  *       public Shipping getShipping();
aoqi@0:  *
aoqi@0:  *       // maps reference to Invoice by containment by default.
aoqi@0:  *       public Invoice getInvoice();
aoqi@0:  *   }
aoqi@0:  *
aoqi@0:  *   &lt;!-- XML Schema mapping for above code frament -->
aoqi@0:  *
aoqi@0:  *   &lt;xs:complexType name="Invoice">
aoqi@0:  *     &lt;xs:complexContent>
aoqi@0:  *       &lt;xs:sequence>
aoqi@0:  *         &lt;xs:element name="customer" type="xs:IDREF"/>
aoqi@0:  *         ....
aoqi@0:  *       &lt;/xs:sequence>
aoqi@0:  *     &lt;/xs:complexContent>
aoqi@0:  *   &lt;/xs:complexType>
aoqi@0:  *
aoqi@0:  *   &lt;xs:complexType name="Shipping">
aoqi@0:  *     &lt;xs:complexContent>
aoqi@0:  *       &lt;xs:sequence>
aoqi@0:  *         &lt;xs:element name="customer" type="xs:IDREF"/>
aoqi@0:  *         ....
aoqi@0:  *       &lt;/xs:sequence>
aoqi@0:  *     &lt;/xs:complexContent>
aoqi@0:  *   &lt;/xs:complexType>
aoqi@0:  *
aoqi@0:  *   &lt;xs:complexType name="Customer">
aoqi@0:  *     &lt;xs:complexContent>
aoqi@0:  *       &lt;xs:sequence>
aoqi@0:  *         ....
aoqi@0:  *       &lt;/xs:sequence>
aoqi@0:  *       &lt;xs:attribute name="CustomerID" type="xs:ID"/>
aoqi@0:  *     &lt;/xs:complexContent>
aoqi@0:  *   &lt;/xs:complexType>
aoqi@0:  *
aoqi@0:  *   &lt;xs:complexType name="CustomerData">
aoqi@0:  *     &lt;xs:complexContent>
aoqi@0:  *       &lt;xs:sequence>
aoqi@0:  *         &lt;xs:element name="customer" type="xs:Customer"/>
aoqi@0:  *         &lt;xs:element name="shipping" type="xs:Shipping"/>
aoqi@0:  *         &lt;xs:element name="invoice"  type="xs:Invoice"/>
aoqi@0:  *       &lt;/xs:sequence>
aoqi@0:  *     &lt;/xs:complexContent>
aoqi@0:  *   &lt;/xs:complexType>
aoqi@0:  *
aoqi@0:  *   &lt;xs:element name"customerData" type="xs:CustomerData"/>
aoqi@0:  *
aoqi@0:  *   &lt;!-- Instance document conforming to the above XML Schema -->
aoqi@0:  *    &lt;customerData>
aoqi@0:  *       &lt;customer customerID="Alice">
aoqi@0:  *           ....
aoqi@0:  *       &lt;/customer>
aoqi@0:  *
aoqi@0:  *       &lt;shipping customer="Alice">
aoqi@0:  *           ....
aoqi@0:  *       &lt;/shipping>
aoqi@0:  *
aoqi@0:  *       &lt;invoice customer="Alice">
aoqi@0:  *           ....
aoqi@0:  *       &lt;/invoice>
aoqi@0:  *   &lt;/customerData>
aoqi@0:  *
aoqi@0:  * </pre>
aoqi@0:  *
aoqi@0:  * <p><b>Example 3: </b> Mapping List to repeating element of type IDREF
aoqi@0:  * <pre>
aoqi@0:  *     // Code fragment
aoqi@0:  *     public class Shipping {
aoqi@0:  *         &#64;XmlIDREF
aoqi@0:  *         &#64;XmlElement(name="Alice")
aoqi@0:  *             public List customers;
aoqi@0:  *     }
aoqi@0:  *
aoqi@0:  *     &lt;!-- XML schema fragment -->
aoqi@0:  *     &lt;xs:complexType name="Shipping">
aoqi@0:  *       &lt;xs:sequence>
aoqi@0:  *         &lt;xs:choice minOccurs="0" maxOccurs="unbounded">
aoqi@0:  *           &lt;xs:element name="Alice" type="xs:IDREF"/>
aoqi@0:  *         &lt;/xs:choice>
aoqi@0:  *       &lt;/xs:sequence>
aoqi@0:  *     &lt;/xs:complexType>
aoqi@0:  * </pre>
aoqi@0:  *
aoqi@0:  * <p><b>Example 4: </b> Mapping a List to a list of elements of type IDREF.
aoqi@0:  * <pre>
aoqi@0:  *     //Code fragment
aoqi@0:  *     public class Shipping {
aoqi@0:  *         &#64;XmlIDREF
aoqi@0:  *         &#64;XmlElements(
aoqi@0:  *             &#64;XmlElement(name="Alice", type="Customer.class")
aoqi@0:  *              &#64;XmlElement(name="John", type="InternationalCustomer.class")
aoqi@0:  *         public List customers;
aoqi@0:  *     }
aoqi@0:  *
aoqi@0:  *     &lt;!-- XML Schema fragment -->
aoqi@0:  *     &lt;xs:complexType name="Shipping">
aoqi@0:  *       &lt;xs:sequence>
aoqi@0:  *         &lt;xs:choice minOccurs="0" maxOccurs="unbounded">
aoqi@0:  *           &lt;xs:element name="Alice" type="xs:IDREF"/>
aoqi@0:  *           &lt;xs:element name="John" type="xs:IDREF"/>
aoqi@0:  *         &lt;/xs:choice>
aoqi@0:  *       &lt;/xs:sequence>
aoqi@0:  *     &lt;/xs:complexType>
aoqi@0:  * </pre>
aoqi@0:  * @author Sekhar Vajjhala, Sun Microsystems, Inc.
aoqi@0:  * @see XmlID
aoqi@0:  * @since JAXB2.0
aoqi@0:  */
aoqi@0: 
aoqi@0: @Retention(RUNTIME) @Target({FIELD, METHOD})
aoqi@0: public @interface XmlIDREF {}