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: * *Example 1: Annotation on a factory method *
* // Example: code fragment
* @XmlRegistry
* class ObjectFactory {
* @XmlElementDecl(name="foo")
* JAXBElement<String> createFoo(String s) { ... }
* }
*
* {@code
*
*
* string
*
* // Example: code fragment corresponding to XML input
* JAXBElement o =
* (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 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. * *
{@code
*
*
*
*
*
*
*
* }
*
* // 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")
* JAXBElement<String> createPeaFoo(String s);
*
* @XmlElementDecl(scope=Pea.class,name="bar")
* JAXBElement<String> createPeaBar(String s);
*
* @XmlElementDecl(name="foo")
* JAXBElement<Integer> createFoo(Integer i);
* }
*
*
* Without scope createFoo and createPeaFoo would become ambiguous
* since both of them map to a XML schema element with the same local
* name "foo".
*
* @see XmlRegistry
* @since 1.6, JAXB 2.0
*/
@Retention(RUNTIME)
@Target({METHOD})
public @interface XmlElementDecl {
/**
* scope of the mapping.
*
* * If this is not {@link XmlElementDecl.GLOBAL}, then this element * declaration mapping is only active within the specified class. */ Class scope() default GLOBAL.class; /** * namespace name of the XML element. *
* If the value is "##default", then the value is the namespace * name for the package of the class containing this factory method. * * @see #name() */ String namespace() default "##default"; /** * 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 #namespace() */ String name(); /** * 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 {@code substitutionHeadName()}. *
* If {@code 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 {@code susbstitutionHeadName()} is "". *
* If {@code 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 {@link * XmlRegistry }, is mapped. *
* If {@code susbtitutionHeadName()} is not "" and the value is * not "##default", then the value is the namespace name. * * @see #substitutionHeadName() */ String substitutionHeadNamespace() default "##default"; /** * 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 #substitutionHeadNamespace() */ String substitutionHeadName() default ""; /** * Default value of this element. * *
* The
'\u0000'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. */ String defaultValue() default "\u0000"; /** * Used in {@link XmlElementDecl#scope()} to * signal that the declaration is in the global scope. */ public final class GLOBAL {} }