XmlRootElement

Usage

The @XmlRootElement annotation can be used with the following program elements:

• a top level class
• an enum type

See "Package Specification" in javax.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: {@link XmlType}, {@link XmlEnum}, {@link XmlAccessorType}, {@link 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>

<!-- 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: 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>