EclipseLink/DesignDocs/293925/Phase6

Phase 6 - Substitution Groups (page under construction)

Provide support for substitution groups.

Annotations

The following annotations will be targeted in this phase:

Annotation	XML Metadata Tag	Package	Type	Field	Method
XmlElements	xml-elements			X	X
XmlElementRef	xml-element-ref			X	X
XmlElementRefs	xml-element-refs			X	X

Example: XmlElements annotation

Java Metadata

The following example will demonstrate how the XmlElements annotation can be applied:

org.example.Foo.java

package org.example;
 
@javax.xml.bind.annotation.XmlRootElement
public class Foo {
    @javax.xml.bind.annotation.XmlElementWrapper(name="items")
    @javax.xml.bind.annotation.XmlElements({
        @javax.xml.bind.annotation.XmlElement(name="A", type=Integer.class),
        @javax.xml.bind.annotation.XmlElement(name="B", type=Float.class)
    })
    public java.util.List items;
}

XML Metadata

xml-elements

If this is present in the XML then it completely replaces the corresponding annotation.

org/example/eclipselink-oxm.xml

This XML file represents metadata overrides for the org.example.Foo class.

<?xml version="1.0" encoding="US-ASCII"?>
<xml-bindings xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/oxm">
    <java-types>
        <java-type name="org.example.Foo">
            <xml-root-element name="foo"/>
            <java-attributes>
                <xml-elements java-attribute="items">
                    <xml-element java-attribute="A" type="java.lang.Integer" />
                    <xml-element java-attribute="B" type="java.lang.Float" />
                </xml-elements>
            </java-attributes>
        </java-type>
    </java-types>
</xml-bindings>

Example: XmlElementRef annotation

Java Metadata

The following example will demonstrate how the XmlElementRef annotation can be applied:

org.example.Foo.java

package org.example;
 
@javax.xml.bind.annotation.XmlRootElement
public class Foo {
    @javax.xml.bind.annotation.XmlElementRef(type=Bar.class)
    public Bar item;
}

org.example.Bar.java

package org.example;
 
@javax.xml.bind.annotation.XmlRootElement(name="foobar")
public class Bar {
    public int id;
}

XML Metadata

xml-element-ref

If this is present in the XML then it completely replaces the corresponding annotation.

org/example/eclipselink-oxm.xml

This XML file represents metadata overrides for the org.example.Foo and org.example.Foo classes.

<?xml version="1.0" encoding="US-ASCII"?>
<xml-bindings xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/oxm">
    <java-types>
        <java-type name="org.example.Foo">
            <xml-root-element name="foo" />
            <java-attributes>
                <xml-element-ref java-attribute="item" type="org.example.Bar"/>
            </java-attributes>
        </java-type>
        <java-type name="org.example.Bar">
            <xml-root-element name="foobar" />
        </java-type>
    </java-types>
</xml-bindings>