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

Usage

The @XmlRootElement annotation 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.

When a top level class or an enum type is annotated with the @XmlRootElement annotation, then its value is represented as XML element in an XML document.

This annotation can be used with the following annotations: XmlType, XmlEnum, XmlAccessorType, XmlAccessorOrder.

Example 1: Associate an element with XML Schema type

    // Example: Code fragment
    @XmlRootElement
    class Point {
       int x;
       int y;
       Point(int _x,int _y) {x=_x;y=_y;}
    }

    //Example: Code fragment corresponding to XML output
    marshal( new Point(3,5), System.out);

<!-- Example: XML output -->
    <point>
      <x> 3 </x>
      <y> 5 </y>
    </point>

The annotation causes an global element declaration to be produced in the schema. The global element declaration is associated with the XML schema type to which the class is mapped.

<!-- Example: XML schema definition -->
    <xs:element name="point" type="point"/>
    <xs:complexType name="point">
      <xs:sequence>
        <xs:element name="x" type="xs:int"/>
        <xs:element name="y" type="xs:int"/>
      </xs:sequence>
    </xs:complexType>

Example 2: Orthogonality to type inheritance

An element declaration annotated on a type is not inherited by its derived types. The following example shows this.

    // Example: Code fragment
    @XmlRootElement
    class Point3D extends Point {
        int z;
        Point3D(int _x,int _y,int _z) {super(_x,_y);z=_z;}
    }

    //Example: Code fragment corresponding to XML output * 
    marshal( new Point3D(3,5,0), System.out );
<!-- Example: XML output -->
    <!-- The element name is point3D not point -->
    <point3D>
      <x>3</x>
      <y>5</y>
      <z>0</z>
    </point3D>

    <!-- Example: XML schema definition -->
    <xs:element name="point3D" type="point3D"/>
    <xs:complexType name="point3D">
      <xs:complexContent>
        <xs:extension base="point">
          <xs:sequence>
            <xs:element name="z" type="xs:int"/>
          </xs:sequence>
        </xs:extension>
      </xs:complexContent>
    </xs:complexType>

Example 3: Associate a global element with XML Schema type to which the class is mapped.

    //Example: Code fragment
    @XmlRootElement(name="PriceElement")
    public class USPrice {
        @XmlElement
        public java.math.BigDecimal price;
    }
<!-- Example: XML schema definition -->
    <xs:element name="PriceElement" type="USPrice"/>
    <xs:complexType name="USPrice">
      <xs:sequence>
        <xs:element name="price" type="xs:decimal"/>
      </sequence>
    </xs:complexType>