XmlElement (Java Platform SE 6) - JDK 5 Documentation v6.0, Java 2 SDK 英文文档

Overview

Package

Class

Use

Tree

Deprecated

Index

Help

Java™ Platform
Standard Ed. 6

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: REQUIRED | OPTIONAL

DETAIL: ELEMENT

javax.xml.bind.annotation
Annotation Type XmlElement

@Retention(value=RUNTIME) @Target(value={FIELD,METHOD}) public @interface XmlElement

Maps a JavaBean property to a XML element derived from property name.

Usage

@XmlElement annotation can be used with the following program elements:

a JavaBean property
non static, non transient field
within XmlElements

The usage is subject to the following constraints:

This annotation can be used with following annotations: XmlID, XmlIDREF, XmlList, XmlSchemaType, XmlValue, XmlAttachmentRef, XmlMimeType, XmlInlineBinaryData, XmlElementWrapper, XmlJavaTypeAdapter
if the type of JavaBean property is a collection type of array, an indexed property, or a parameterized list, and this annotation is used with XmlElements then, @XmlElement.type() must be DEFAULT.class since the collection item type is already known.

A JavaBean property, when annotated with @XmlElement annotation is mapped to a local element in the XML Schema complex type to which the containing class is mapped.

Example 1: Map a public non static non final field to local element

     //Example: Code fragment
     public class USPrice {
         @XmlElement(name="itemprice")
         public java.math.BigDecimal price;
     }

     <!-- Example: Local XML Schema element -->
     <xs:complexType name="USPrice"/>
       <xs:sequence>
         <xs:element name="itemprice" type="xs:decimal" minOccurs="0"/>
       </sequence>
     </xs:complexType>

Example 2: Map a field to a nillable element.


     //Example: Code fragment
     public class USPrice {
         @XmlElement(nillable=true)
         public java.math.BigDecimal price;
     }

     <!-- Example: Local XML Schema element -->
     <xs:complexType name="USPrice">
       <xs:sequence>
         <xs:element name="price" type="xs:decimal" nillable="true" minOccurs="0"/>
       </sequence>
     </xs:complexType>

Example 3: Map a field to a nillable, required element.


     //Example: Code fragment
     public class USPrice {
         @XmlElement(nillable=true, required=true)
         public java.math.BigDecimal price;
     }

     <!-- Example: Local XML Schema element -->
     <xs:complexType name="USPrice">
       <xs:sequence>
         <xs:element name="price" type="xs:decimal" nillable="true" minOccurs="1"/>
       </sequence>
     </xs:complexType>

Example 4: Map a JavaBean property to an XML element with anonymous type.

See Example 6 in @XmlType.

Since:: JAXB2.0

Optional Element Summary

String defaultValue
          Default value of this element.

String name
          Name of the XML Schema element.

String namespace
          XML target namespace of the XML Schema element.

boolean nillable
          Customize the element declaration to be nillable.

boolean required
          Customize the element declaration to be required.

Class type
          The Java class being referenced.

Optional Element Summary
`String`	`defaultValue` Default value of this element.
`String`	`name` Name of the XML Schema element.
`String`	`namespace` XML target namespace of the XML Schema element.
`boolean`	`nillable` Customize the element declaration to be nillable.
`boolean`	`required` Customize the element declaration to be required.
`Class`	`type` The Java class being referenced.

name

public abstract String name

Name of the XML Schema element.

If the value is "##default", then element name is derived from the JavaBean property name.

Default:: "##default"

nillable

public abstract boolean nillable

Customize the element declaration to be nillable.

If nillable() is true, then the JavaBean property is mapped to a XML Schema nillable element declaration.

Default:: false

required

public abstract boolean required

Customize the element declaration to be required.

If required() is true, then Javabean property is mapped to an XML schema element declaration with minOccurs="1". maxOccurs is "1" for a single valued property and "unbounded" for a multivalued property.

If required() is false, then the Javabean property is mapped to XML Schema element declaration with minOccurs="0". maxOccurs is "1" for a single valued property and "unbounded" for a multivalued property.

Default:: false

namespace

public abstract String namespace

XML target namespace of the XML Schema element.

If the value is "##default", then the namespace is determined as follows:

If the enclosing package has XmlSchema annotation, and its elementFormDefault is QUALIFIED, then the namespace of the enclosing class.
Otherwise "" (which produces unqualified element in the default namespace.

Default:: "##default"

defaultValue

public abstract String defaultValue

Default value of this element.

The '' value specified as a default of this annotation element is used as a poor-man's substitute for null to allow implementations to recognize the 'no default value' state.

Default:: "\u0000"

type

public abstract Class type

The Java class being referenced.

Default:: javax.xml.bind.annotation.XmlElement.DEFAULT.class