EclipseLink/DesignDocs/293925/MOXyExtensions/XMLDirectMapping

XMLDirectMapping (page under construction)

Requirements

Provide support for XML direct mappings. The following structures are to be extended to support XML direct mapping configuration:

• xml-attribute
• xml-element

The following information must be configurable via XML metadata

<xml-direct-mapping xmlns="http://www.eclipse.org/eclipselink/xsds/persistence">
	<attribute-name>String</attribute-name>
	<read-only>false</read-only>
	<get-method>String</get-method>
	<set-method>String</set-method>
	<properties>
		<property name="String">
			<value>Text</value>
		</property>
		<property name="String">
			<value>Text</value>
		</property>
	</properties>
	<field name="String"/>
	<null-value>String</null-value>
	<converter/>
	<attribute-classification>String</attribute-classification>
	<is-cdata>1</is-cdata>
	<null-policy>
		<xsi-nil-represents-null>false</xsi-nil-represents-null>
		<empty-node-represents-null>false</empty-node-represents-null>
		<null-representation-for-xml>XSI_NIL</null-representation-for-xml>
	</null-policy>
</xml-direct-mapping>

Example

The following example will demonstrate how to configure XML direct mappings via XML metadata.

org.example.Employee.java

package org.example;
 
public class Employee {
    public int empId;
    public String firstName;
    public String lastName;
    public String projectName;
}

Deployment XML

<class-mapping-descriptor xsi:type="xml-class-mapping-descriptor">
    <alias>Employee</alias>
    <attribute-mappings>
        <attribute-mapping xsi:type="xml-direct-mapping">
           <attribute-name>empId</attribute-name>
           <field name="@id" xsi:type="node"/>
        </attribute-mapping>
        <attribute-mapping xsi:type="xml-direct-mapping">
           <attribute-name>firstName</attribute-name>
           <field name="name/first-name/text()" xsi:type="node"/>
        </attribute-mapping>
        <attribute-mapping xsi:type="xml-direct-mapping">
           <attribute-name>lastName</attribute-name>
           <field name="name/last-name/text()" xsi:type="node"/>
        </attribute-mapping>
        <attribute-mapping xsi:type="xml-direct-mapping">
           <attribute-name>projectName</attribute-name>
           <field name="projects/prj:project/text()" xsi:type="node"/>
        </attribute-mapping>
    <attribute-mappings>
    <descriptor-type>aggregate</descriptor-type>
    <default-root-element>employee</default-root-element>
    <default-root-element-field name="employee" xsi:type="node"/>
    <namespace-resolver>
        <namespaces>
            <namespace>
                <prefix>prj</prefix>
                <namespace-uri>http://www.example.com/projects</namespace-uri>
            </namespace>
        </namespaces>
        <default-namespace-uri>http://www.example.com/employees</default-namespace-uri>
    </namespace-resolver>
</class-mapping-descriptor>

XML Instance Document

<?xml version="1.0" encoding="UTF-8"?>
<employee id="66" xmlns="http://www.example.com/employees" xmlns:prj="http://www.example.com/projects">
    <first-name>Joe</first-name>
    <last-name>Black</last-name>
    <prj:project>XML External Metadata Support</prj:project>
</employee>

XML Metadata

org/example/eclipselink-oxm.xml

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

<?xml version="1.0" encoding="US-ASCII"?>
<xml-bindings xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/oxm">
    <xml-schema namespace="http://www.example.com/employees">
        <xml-ns namespace-uri="http://www.example.com/projects" prefix="prj"/>
    </xml-schema>
    <java-types>
        <java-type name="org.example.Employee">
            <xml-root-element name="employee" />
            <java-attributes>
                <xml-attribute java-attribute="empId" name="id" />
                <xml-element java-attribute="firstName" name="first-name" />
                <xml-element java-attribute="lastName" name="last-name" />
                <xml-element java-attribute="projectName" name="prj:project" />
            </java-attributes>
        </java-type>
    </java-types>
</xml-bindings>

Open Issues

This section lists the open issues that are still pending that must be decided prior to fully implementing this project's requirements.

Issue #	Owner	Description / Notes
1	D. McCann	How do we handle path-based mappings? Design will be documented here.

Decisions

This section lists decisions made. These are intended to document the resolution of open issues or constraints added to the project that are important.

Issue #	Description / Notes	Decision