https://github.com/eclipse-ee4j/jaxb-api/jakarta.xml.bind-api: Jakarta XML Binding API (Eclipse Foundation)
  • Roman Grigoriadi (Oracle Corporation) 
/*
 * Copyright (c) 2004, 2020 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 jakarta.xml.bind.annotation;

import static java.lang.annotation.ElementType.TYPE;
import java.lang.annotation.Retention;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Target;



Maps a class or an enum type to a XML Schema type.

Usage


 The @XmlType annnotation can be used with the following program elements: 
    
  
  •  a top level class 
    • 
  
  •  an enum type 
    • 



See "Package Specification" in jakarta.xml.bind.package javadoc for
additional common information.


 Mapping a Class 



A class maps to a XML Schema type. A class is a data container for
values represented by properties and fields. A schema type is a
data container for values represented by schema components within a
schema type's content model (e.g. model groups, attributes etc).

 To be mapped, a class must either have a public no-arg constructor or a static no-arg factory method. The static factory method can be specified in factoryMethod() and factoryClass() annotation elements. The static factory method or the no-arg constructor is used during unmarshalling to create an instance of this class. If both are present, the static factory method overrides the no-arg constructor. 
 A class maps to either a XML Schema complex type or a XML Schema simple type. The XML Schema type is derived based on the mapping of JavaBean properties and fields contained within the class. The schema type to which the class is mapped can either be named or anonymous. A class can be mapped to an anonymous schema type by annotating the class with @XmlType(name=""). 

Either a global element, local element or a local attribute can be
associated with an anonymous type as follows:

    
  
  • global element:  A global element of an anonymous type can be derived by annotating the class with @XmlRootElement. See Example 3 below. 
    • 
  
  • local element:  A JavaBean property that references
     a class annotated with @XmlType(name="") and is mapped to the
     element associated with the anonymous type. See Example 4
     below.
    • 
  
  • attribute:  A JavaBean property that references
     a class annotated with @XmlType(name="") and is mapped to the
     attribute associated with the anonymous type. See Example 5 below. 
    • 


 Mapping to XML Schema Complex Type 

    
  
  • If class is annotated with @XmlType(name="") , it is mapped to an anonymous type otherwise, the class name maps to a complex type name. The XmlName() annotation element can be used to customize the name.
    • 
  
  •  Properties and fields that are mapped to elements are mapped to a content model within a complex type. The annotation element propOrder() can be used to customize the content model to be xs:all or xs:sequence. It is used for specifying the order of XML elements in xs:sequence. 
    • 
  
  •  Properties and fields can be mapped to attributes within the
       complex type.  
    • 
  
  •  The targetnamespace of the XML Schema type can be customized using the annotation element namespace(). 
    • 




 Mapping class to XML Schema simple type 

 A class can be mapped to a XML Schema simple type using the @XmlValue annotation. For additional details and examples, see @XmlValue annotation type. 

The following table shows the mapping of the class to a XML Schema
complex type or simple type. The notational symbols used in the table are:

    
  
  •  -> : represents a mapping 
    • 
  
  •  [x]+  : one or more occurrences of x 
    • 
  
  •  [ @XmlValue property ]: JavaBean property annotated with @XmlValue
    • 
  
  •  X     : don't care




  

    Mapping class to XML Schema simple type
    
      

        Target
        propOrder
        ClassBody
        ComplexType
        SimpleType
      

    
    
      

        Class
        {}
        [property]+ -> elements
        complexcontent
xs:all		
         
      

      

        Class
        non empty
        [property]+ -> elements
        complexcontent
xs:sequence		
         
      

      

        Class
        X
        no property -> element
        complexcontent
empty sequence		
         
      

      

        Class
        X
        1 [@XmlValue property] && 
 [property]+ -> attributes		
        simplecontent
         
      

      

        Class
        X
        1 [@XmlValue property] && 
 no properties -> attribute		
         
        simpletype
      

    
  




 Mapping an enum type 
 An enum type maps to a XML schema simple type with enumeration facets. The following annotation elements are ignored since they are not meaningful: propOrder() , factoryMethod() , factoryClass() . 
 Usage with other annotations 


 This annotation can be used with the following annotations: XmlRootElement, XmlAccessorOrder, XmlAccessorType, XmlEnum. However, XmlAccessorOrder and XmlAccessorType are ignored when this annotation is used on an enum type. 
  Example 1:  Map a class to a complex type with
  xs:sequence with a customized ordering of JavaBean properties.



 @XmlType(propOrder={"street", "city" , "state", "zip", "name" }) public class USAddress { String getName() {..}; void setName(String) {..}; String getStreet() {..}; void setStreet(String) {..}; String getCity() {..}; void setCity(String) {..}; String getState() {..}; void setState(String) {..}; java.math.BigDecimal getZip() {..}; void setZip(java.math.BigDecimal) {..}; } 
  <!-- XML Schema mapping for USAddress -->
  <xs:complexType name="USAddress">
    <xs:sequence>
      <xs:element name="street" type="xs:string"/>
      <xs:element name="city" type="xs:string"/>
      <xs:element name="state" type="xs:string"/>
      <xs:element name="zip" type="xs:decimal"/>
      <xs:element name="name" type="xs:string"/>
    </xs:all>
  </xs:complexType>



  Example 2:  Map a class to a complex type with
    xs:all 


@XmlType(propOrder={}) public class USAddress { ...} 
<!-- XML Schema mapping for USAddress -->
<xs:complexType name="USAddress">
  <xs:all>
    <xs:element name="name" type="xs:string"/>
    <xs:element name="street" type="xs:string"/>
    <xs:element name="city" type="xs:string"/>
    <xs:element name="state" type="xs:string"/>
    <xs:element name="zip" type="xs:decimal"/>
  </xs:sequence>
</xs:complexType>



  Example 3:  Map a class to a global element with an
anonymous type.



 @XmlRootElement @XmlType(name="") public class USAddress { ...} 
  <!-- XML Schema mapping for USAddress -->
  <xs:element name="USAddress">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="name" type="xs:string"/>
        <xs:element name="street" type="xs:string"/>
        <xs:element name="city" type="xs:string"/>
        <xs:element name="state" type="xs:string"/>
        <xs:element name="zip" type="xs:decimal"/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>



  Example 4:  Map a property to a local element with
anonymous type.

 //Example: Code fragment public class Invoice { USAddress addr; ... } @XmlType(name="") public class USAddress { ... } } 
  <!-- XML Schema mapping for USAddress -->
  <xs:complexType name="Invoice">
    <xs:sequence>
      <xs:element name="addr">
        <xs:complexType>
          <xs:element name="name", type="xs:string"/>
          <xs:element name="city", type="xs:string"/>
          <xs:element name="city" type="xs:string"/>
          <xs:element name="state" type="xs:string"/>
          <xs:element name="zip" type="xs:decimal"/>
        </xs:complexType>
      ...
    </xs:sequence>
  </xs:complexType>



  Example 5:  Map a property to an attribute with
anonymous type.

 //Example: Code fragment public class Item { public String name; @XmlAttribute public USPrice price; } // map class to anonymous simple type. @XmlType(name="") public class USPrice { @XmlValue public java.math.BigDecimal price; } 
    <!-- Example: XML Schema fragment -->
    <xs:complexType name="Item">
      <xs:sequence>
        <xs:element name="name" type="xs:string"/>
        <xs:attribute name="price">
          <xs:simpleType>
            <xs:restriction base="xs:decimal"/>
          </xs:simpleType>
        </xs:attribute>
      </xs:sequence>
    </xs:complexType>


 
  Example 6:  Define a factoryClass and factoryMethod

     @XmlType(name="USAddressType", factoryClass=USAddressFactory.class,
     factoryMethod="getUSAddress")
     public class USAddress {
         private String city;
         private String name;
         private String state;
         private String street;
         private int    zip;
     public USAddress(String name, String street, String city,
         String state, int zip) {
         this.name = name;
         this.street = street;
         this.city = city;
         this.state = state;
         this.zip = zip;
     }
 }
 public class USAddressFactory {
     public static USAddress getUSAddress(){
      return new USAddress("Mark Baker", "23 Elm St",
         "Dayton", "OH", 90952);
 }


 
  Example 7:  Define factoryMethod and use the default factoryClass

     @XmlType(name="USAddressType", factoryMethod="getNewInstance")
     public class USAddress {
         private String city;
         private String name;
         private String state;
         private String street;
         private int    zip;
         private USAddress() {}
         public static USAddress getNewInstance(){
             return new USAddress();
         }
     }



Author:Sekhar Vajjhala, Sun Microsystems, Inc.
See Also:
Since:1.6, JAXB 2.0
/**
 * <p>
 * Maps a class or an enum type to a XML Schema type.
 *
 * <p><b>Usage</b></p>
 * <p> The {@code @XmlType} annnotation can be used with the following program
 * elements:
 * <ul>
 *   <li> a top level class </li>
 *   <li> an enum type </li>
 * </ul>
 *
 * <p>See "Package Specification" in jakarta.xml.bind.package javadoc for
 * additional common information.</p>
 *
 * <h2> Mapping a Class </h2>
 * <p>
 * A class maps to a XML Schema type. A class is a data container for
 * values represented by properties and fields. A schema type is a
 * data container for values represented by schema components within a
 * schema type's content model (e.g. model groups, attributes etc).
 * <p> To be mapped, a class must either have a public no-arg
 * constructor or a static no-arg factory method. The static factory
 * method can be specified in {@code factoryMethod()} and
 * {@code factoryClass()} annotation elements. The static factory
 * method or the no-arg constructor is used during unmarshalling to
 * create an instance of this class. If both are present, the static
 * factory method overrides the no-arg constructor.
 * <p>
 * A class maps to either a XML Schema complex type or a XML Schema simple
 * type. The XML Schema type is derived based on the
 * mapping of JavaBean properties and fields contained within the
 * class. The schema type to which the class is mapped can either be
 * named or anonymous. A class can be mapped to an anonymous schema
 * type by annotating the class with {@code @XmlType(name="")}.
 * <p>
 * Either a global element, local element or a local attribute can be
 * associated with an anonymous type as follows:
 * <ul>
 *   <li><b>global element: </b> A global element of an anonymous
 *      type can be derived by annotating the class with @{@link
 *      XmlRootElement}. See Example 3 below. </li>
 *
 *   <li><b>local element: </b> A JavaBean property that references
 *      a class annotated with @XmlType(name="") and is mapped to the
 *      element associated with the anonymous type. See Example 4
 *      below.</li>
 *
 *   <li><b>attribute: </b> A JavaBean property that references
 *      a class annotated with @XmlType(name="") and is mapped to the
 *      attribute associated with the anonymous type. See Example 5 below. </li>
 * </ul>
 * <b> Mapping to XML Schema Complex Type </b>
 * <ul>
 *   <li>If class is annotated with {@code @XmlType(name="") }, it
 *   is mapped to an anonymous type otherwise, the class name maps
 *   to a complex type name. The {@code XmlName()} annotation element
 *   can be used to customize the name.</li>
 *
 *   <li> Properties and fields that are mapped to elements are mapped to a
 *   content model within a complex type. The annotation element
 *   {@code propOrder()} can be used to customize the content model to be
 *   {@code xs:all} or {@code xs:sequence}.  It is used for specifying
 *   the order of XML elements in {@code xs:sequence}. </li>
 *
 *   <li> Properties and fields can be mapped to attributes within the
 *        complex type.  </li>
 *
 *   <li> The targetnamespace of the XML Schema type can be customized
 *        using the annotation element {@code namespace()}. </li>
 * </ul>
 *
 * <p>
 * <b> Mapping class to XML Schema simple type </b>
 * <p>
 * A class can be mapped to a XML Schema simple type using the
 * {@code @XmlValue} annotation. For additional details and examples,
 * see @{@link XmlValue} annotation type.
 * <p>
 * The following table shows the mapping of the class to a XML Schema
 * complex type or simple type. The notational symbols used in the table are:
 * <ul>
 *   <li> {@literal ->}    : represents a mapping </li>
 *   <li> [x]+  : one or more occurrences of x </li>
 *   <li> [ {@code @XmlValue} property ]: JavaBean property annotated with
 *         {@code @XmlValue}</li>
 *   <li> X     : don't care
 * </ul>
 * <blockquote>
 *   <table class="striped">
 *     <caption>Mapping class to XML Schema simple type</caption>
 *     <thead>
 *       <tr>
 *         <th scope="col">Target</th>
 *         <th scope="col">propOrder</th>
 *         <th scope="col">ClassBody</th>
 *         <th scope="col">ComplexType</th>
 *         <th scope="col">SimpleType</th>
 *       </tr>
 *     </thead>
 *
 *     <tbody>
 *       <tr>
 *         <td>Class</td>
 *         <td>{}</td>
 *         <th scope="row">[property]+ {@literal ->} elements</th>
 *         <td>complexcontent<br>xs:all</td>
 *         <td> </td>
 *       </tr>
 *
 *       <tr>
 *         <td>Class</td>
 *         <td>non empty</td>
 *         <th scope="row">[property]+ {@literal ->} elements</th>
 *         <td>complexcontent<br>xs:sequence</td>
 *         <td> </td>
 *       </tr>
 *
 *       <tr>
 *         <td>Class</td>
 *         <td>X</td>
 *         <th scope="row">no property {@literal ->} element</th>
 *         <td>complexcontent<br>empty sequence</td>
 *         <td> </td>
 *       </tr>
 *
 *       <tr>
 *         <td>Class</td>
 *         <td>X</td>
 *         <th scope="row">1 [{@code @XmlValue} property] {@literal &&} <br> [property]+ {@literal ->} attributes</th>
 *         <td>simplecontent</td>
 *         <td> </td>
 *       </tr>
 *
 *       <tr>
 *         <td>Class</td>
 *         <td>X</td>
 *         <th scope="row">1 [{@code @XmlValue} property] {@literal &&} <br> no properties {@literal ->} attribute</th>
 *         <td> </td>
 *         <td>simpletype</td>
 *       </tr>
 *     </tbody>
 *   </table>
 * </blockquote>
 *
 * <h3> Mapping an enum type </h3>
 *
 * An enum type maps to a XML schema simple type with enumeration
 * facets. The following annotation elements are ignored since they
 * are not meaningful: {@code propOrder()} , {@code factoryMethod()} ,
 * {@code factoryClass()} .
 *
 *  <h3> Usage with other annotations </h3>
 * <p> This annotation can be used with the following annotations:
 * {@link XmlRootElement}, {@link XmlAccessorOrder}, {@link XmlAccessorType},
 * {@link XmlEnum}. However, {@link
 * XmlAccessorOrder} and {@link XmlAccessorType} are ignored when this
 * annotation is used on an enum type.
 *
 * <p> <b> Example 1: </b> Map a class to a complex type with
 *   xs:sequence with a customized ordering of JavaBean properties.
 * </p>
 *
 * <pre>
 *   &#64;XmlType(propOrder={"street", "city" , "state", "zip", "name" })
 *   public class USAddress {
 *     String getName() {..};
 *     void setName(String) {..};
 *
 *     String getStreet() {..};
 *     void setStreet(String) {..};
 *
 *     String getCity() {..};
 *     void setCity(String) {..};
 *
 *     String getState() {..};
 *     void setState(String) {..};
 *
 *     java.math.BigDecimal getZip() {..};
 *     void setZip(java.math.BigDecimal) {..};
 *   }
 * {@code
 *
 *   <!-- XML Schema mapping for USAddress -->
 *   <xs:complexType name="USAddress">
 *     <xs:sequence>
 *       <xs:element name="street" type="xs:string"/>
 *       <xs:element name="city" type="xs:string"/>
 *       <xs:element name="state" type="xs:string"/>
 *       <xs:element name="zip" type="xs:decimal"/>
 *       <xs:element name="name" type="xs:string"/>
 *     </xs:all>
 *   </xs:complexType>
 * }</pre>
 * <p> <b> Example 2: </b> Map a class to a complex type with
 *     xs:all </p>
 * <pre>
 * &#64;XmlType(propOrder={})
 * public class USAddress { ...}
 * {@code
 *
 * <!-- XML Schema mapping for USAddress -->
 * <xs:complexType name="USAddress">
 *   <xs:all>
 *     <xs:element name="name" type="xs:string"/>
 *     <xs:element name="street" type="xs:string"/>
 *     <xs:element name="city" type="xs:string"/>
 *     <xs:element name="state" type="xs:string"/>
 *     <xs:element name="zip" type="xs:decimal"/>
 *   </xs:sequence>
 * </xs:complexType>
 *}</pre>
 * <p> <b> Example 3: </b> Map a class to a global element with an
 * anonymous type.
 * </p>
 * <pre>
 *   &#64;XmlRootElement
 *   &#64;XmlType(name="")
 *   public class USAddress { ...}
 * {@code
 *
 *   <!-- XML Schema mapping for USAddress -->
 *   <xs:element name="USAddress">
 *     <xs:complexType>
 *       <xs:sequence>
 *         <xs:element name="name" type="xs:string"/>
 *         <xs:element name="street" type="xs:string"/>
 *         <xs:element name="city" type="xs:string"/>
 *         <xs:element name="state" type="xs:string"/>
 *         <xs:element name="zip" type="xs:decimal"/>
 *       </xs:sequence>
 *     </xs:complexType>
 *   </xs:element>
 * }</pre>
 *
 * <p> <b> Example 4: </b> Map a property to a local element with
 * anonymous type.
 * <pre>
 *   //Example: Code fragment
 *   public class Invoice {
 *       USAddress addr;
 *           ...
 *       }
 *
 *   &#64;XmlType(name="")
 *   public class USAddress { ... }
 *   }
 * {@code
 *
 *   <!-- XML Schema mapping for USAddress -->
 *   <xs:complexType name="Invoice">
 *     <xs:sequence>
 *       <xs:element name="addr">
 *         <xs:complexType>
 *           <xs:element name="name", type="xs:string"/>
 *           <xs:element name="city", type="xs:string"/>
 *           <xs:element name="city" type="xs:string"/>
 *           <xs:element name="state" type="xs:string"/>
 *           <xs:element name="zip" type="xs:decimal"/>
 *         </xs:complexType>
 *       ...
 *     </xs:sequence>
 *   </xs:complexType>
 * }</pre>
 *
 * <p> <b> Example 5: </b> Map a property to an attribute with
 * anonymous type.
 *
 * <pre>
 *
 *     //Example: Code fragment
 *     public class Item {
 *         public String name;
 *         &#64;XmlAttribute
 *         public USPrice price;
 *     }
 *
 *     // map class to anonymous simple type.
 *     &#64;XmlType(name="")
 *     public class USPrice {
 *         &#64;XmlValue
 *         public java.math.BigDecimal price;
 *     }
 * {@code
 *
 *     <!-- Example: XML Schema fragment -->
 *     <xs:complexType name="Item">
 *       <xs:sequence>
 *         <xs:element name="name" type="xs:string"/>
 *         <xs:attribute name="price">
 *           <xs:simpleType>
 *             <xs:restriction base="xs:decimal"/>
 *           </xs:simpleType>
 *         </xs:attribute>
 *       </xs:sequence>
 *     </xs:complexType>
 * }</pre>
 *
 *  <p> <b> Example 6: </b> Define a factoryClass and factoryMethod
 *
 * <pre>
 *      &#64;XmlType(name="USAddressType", factoryClass=USAddressFactory.class,
 *      factoryMethod="getUSAddress")
 *      public class USAddress {
 *
 *          private String city;
 *          private String name;
 *          private String state;
 *          private String street;
 *          private int    zip;
 *
 *      public USAddress(String name, String street, String city,
 *          String state, int zip) {
 *          this.name = name;
 *          this.street = street;
 *          this.city = city;
 *          this.state = state;
 *          this.zip = zip;
 *      }
 *  }
 *
 *  public class USAddressFactory {
 *      public static USAddress getUSAddress(){
 *       return new USAddress("Mark Baker", "23 Elm St",
 *          "Dayton", "OH", 90952);
 *  }
 *
 * </pre>
 *
 *  <p> <b> Example 7: </b> Define factoryMethod and use the default factoryClass
 *
 * <pre>
 *      &#64;XmlType(name="USAddressType", factoryMethod="getNewInstance")
 *      public class USAddress {
 *
 *          private String city;
 *          private String name;
 *          private String state;
 *          private String street;
 *          private int    zip;
 *
 *          private USAddress() {}
 *
 *          public static USAddress getNewInstance(){
 *              return new USAddress();
 *          }
 *      }
 * </pre>
 *
 * @author Sekhar Vajjhala, Sun Microsystems, Inc.
 * @see XmlElement
 * @see XmlAttribute
 * @see XmlValue
 * @see XmlSchema
 * @since 1.6, JAXB 2.0
 */

@Retention(RUNTIME) @Target({TYPE})
public @interface XmlType {
    
Name of the XML Schema type which the class is mapped.

/**
     * Name of the XML Schema type which the class is mapped.
     */
    String name() default "##default" ;

    
Specifies the order for XML Schema elements when class is
mapped to a XML Schema complex type.

 Refer to the table for how the propOrder affects the
mapping of class 


 The propOrder is a list of names of JavaBean properties in
    the class. Each name in the list is the name of a Java
    identifier of the JavaBean property. The order in which
    JavaBean properties are listed is the order of XML Schema
    elements to which the JavaBean properties are mapped. 


 All of the JavaBean properties being mapped to XML Schema elements
    must be listed.

 A JavaBean property or field listed in propOrder must not be transient or annotated with @XmlTransient. 
 The default ordering of JavaBean properties is determined by @XmlAccessorOrder. 
/**
     * Specifies the order for XML Schema elements when class is
     * mapped to a XML Schema complex type.
     *
     * <p> Refer to the table for how the propOrder affects the
     * mapping of class </p>
     *
     * <p> The propOrder is a list of names of JavaBean properties in
     *     the class. Each name in the list is the name of a Java
     *     identifier of the JavaBean property. The order in which
     *     JavaBean properties are listed is the order of XML Schema
     *     elements to which the JavaBean properties are mapped. </p>
     * <p> All of the JavaBean properties being mapped to XML Schema elements
     *     must be listed.
     * <p> A JavaBean property or field listed in propOrder must not
     *     be transient or annotated with {@code @XmlTransient}.
     * <p> The default ordering of JavaBean properties is determined
     *     by @{@link XmlAccessorOrder}.
     */
    String[] propOrder() default {""};

    
Name of the target namespace of the XML Schema type. By
default, this is the target namespace to which the package
containing the class is mapped.

/**
     * Name of the target namespace of the XML Schema type. By
     * default, this is the target namespace to which the package
     * containing the class is mapped.
     */
    String namespace() default "##default" ;

    
Class containing a no-arg factory method for creating an
instance of this class. The default is this class.

If factoryClass is DEFAULT.class and factoryMethod is "", then there is no static factory method. 
If factoryClass is DEFAULT.class and factoryMethod is not "", then factoryMethod is the name of a static factory method in this class. 
If factoryClass is not DEFAULT.class, then factoryMethod must not be "" and must be the name of a static factory method specified in factoryClass. 
/**
     * Class containing a no-arg factory method for creating an
     * instance of this class. The default is this class.
     *
     * <p>If {@code factoryClass} is DEFAULT.class and
     * {@code factoryMethod} is "", then there is no static factory
     * method.
     *
     * <p>If {@code factoryClass} is DEFAULT.class and
     * {@code factoryMethod} is not "", then
     * {@code factoryMethod} is the name of a static factory method
     * in this class.
     *
     * <p>If {@code factoryClass} is not DEFAULT.class, then
     * {@code factoryMethod} must not be "" and must be the name of
     * a static factory method specified in {@code factoryClass}.
     */
    Class factoryClass() default DEFAULT.class;

    
Used in XmlType.factoryClass() to signal that either factory mehod is not used or that it's in the class with this XmlType itself. 
/**
     * Used in {@link XmlType#factoryClass()} to
     * signal that either factory mehod is not used or
     * that it's in the class with this {@link XmlType} itself.
     */
    static final class DEFAULT {}

    
Name of a no-arg factory method in the class specified in factoryClass factoryClass(). 
/**
     * Name of a no-arg factory method in the class specified in
     * {@code factoryClass} factoryClass().
     *
     */
    String factoryMethod() default "";
}