Annotation Type XmlElementDecl
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@Retention(value=RUNTIME) @Target(value=METHOD) public @interface XmlElementDecl
Maps a factory method to a XML element.Usage
The annotation creates a mapping between an XML schema element declaration and a element factory method that returns a JAXBElement instance representing the element declaration. Typically, the element factory method is generated (and annotated) from a schema into the ObjectFactory class in a Java package that represents the binding of the element declaration's target namespace. Thus, while the annotation syntax allows @XmlElementDecl to be used on any method, semantically its use is restricted to annotation of element factory method. The usage is subject to the following constraints:- The class containing the element factory method annotated with @XmlElementDecl must be marked with
XmlRegistry. - The element factory method must take one parameter assignable to
Object.
Example 1: Annotation on a factory method
// Example: code fragment @XmlRegistry class ObjectFactory { @XmlElementDecl(name="foo") JAXBElement<String> createFoo(String s) { ... } }<!-- XML input --> <foo>string // Example: code fragment corresponding to XML input JAXBElemento = (JAXBElement )unmarshaller.unmarshal(aboveDocument); // print JAXBElement instance to show values System.out.println(o.getName()); // prints "{}foo" System.out.println(o.getValue()); // prints "string" System.out.println(o.getValue().getClass()); // prints "java.lang.String" <!-- Example: XML schema definition --> <xs:element name="foo" type="xs:string"/> Example 2: Element declaration with non local scope
The following example illustrates the use of scope annotation parameter in binding of element declaration in schema derived code.
The following example may be replaced in a future revision of this javadoc.
<!-- Example: XML schema definition --> <xs:schema> <xs:complexType name="pea"> <xs:choice maxOccurs="unbounded"> <xs:element name="foo" type="xs:string"/> <xs:element name="bar" type="xs:string"/> </xs:choice> </xs:complexType> <xs:element name="foo" type="xs:int"/> </xs:schema>// Example: expected default binding class Pea { @XmlElementRefs({ @XmlElementRef(name="foo",type=JAXBElement.class) @XmlElementRef(name="bar",type=JAXBElement.class) }) List<JAXBElement<String>> fooOrBar; } @XmlRegistry class ObjectFactory { @XmlElementDecl(scope=Pea.class,name="foo") JAXBElementWithout scope createFoo and createPeaFoo would become ambiguous since both of them map to a XML schema element with the same local name "foo".createPeaFoo(String s); @XmlElementDecl(scope=Pea.class,name="bar") JAXBElement createPeaBar(String s); @XmlElementDecl(name="foo") JAXBElement createFoo(Integer i); } - Since:
- JAXB 2.0
- See Also:
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XmlRegistry
- The class containing the element factory method annotated with @XmlElementDecl must be marked with
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Required Element Summary
Required Elements Modifier and Type Required Element and Description Stringnamelocal name of the XML element.
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Optional Element Summary
Optional Elements Modifier and Type Optional Element and Description StringdefaultValueDefault value of this element.Stringnamespacenamespace name of the XML element.Classscopescope of the mapping.StringsubstitutionHeadNameXML local name of a substitution group's head element.StringsubstitutionHeadNamespacenamespace name of a substitution group's head XML element.
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Element Detail
name
public abstract String name
local name of the XML element.Note to reviewers: There is no default name; since the annotation is on a factory method, it is not clear that the method name can be derived from the factory method name.
- See Also:
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namespace()
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scope
public abstract Class scope
scope of the mapping.If this is not
XmlElementDecl.GLOBAL, then this element declaration mapping is only active within the specified class.- Default:
- javax.xml.bind.annotation.XmlElementDecl.GLOBAL.class
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substitutionHeadNamespace
public abstract String substitutionHeadNamespace
namespace name of a substitution group's head XML element.This specifies the namespace name of the XML element whose local name is specified by substitutionHeadName().
If susbtitutionHeadName() is "", then this value can only be "##default". But the value is ignored since since this element is not part of susbtitution group when the value of susbstitutionHeadName() is "".
If susbtitutionHeadName() is not "" and the value is "##default", then the namespace name is the namespace name to which the package of the containing class, marked with
XmlRegistry, is mapped.If susbtitutionHeadName() is not "" and the value is not "##default", then the value is the namespace name.
- See Also:
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substitutionHeadName()
- Default:
- "##default"
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substitutionHeadName
public abstract String substitutionHeadName
XML local name of a substitution group's head element.If the value is "", then this element is not part of any substitution group.
- See Also:
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substitutionHeadNamespace()
- Default:
- ""
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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"
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