XML Composite Collection Mapping

Use XML composite collection mappings to represent one-to-many relationships. Composite collection XML mappings can reference any class that has a TopLink descriptor. The attribute in the object mapped must implement either the Java Collection interface (for example, Vector or HashSet) or Map interface (for example, Hashtable or TreeMap). The CompositeCollectionMapping class allows a reference to the mapped class and the indexing type for that class.

Given the XML schema in Example 65-48, Figure 65-27 illustrates an XML composite collection mapping to different elements by position in a corresponding XML document. Example 65-49 shows how to configure this mapping in Java for a Collection attribute and Example 65-50 shows how to configure this mapping in Java for a Map attribute.

Example 65-48 Schema for XML Composite Collection Mapping

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <xsd:element name="customer" type="customer-type"/>
    <xsd:complexType name="customer-type">
        <xsd:sequence>
            <xsd:element name="first-name" type="xsd:string"/>
            <xsd:element name="last-name" type="xsd:string"/>
            <xsd:element name="phone-number">
                <xsd:complexType>
                    <xsd:sequence>
                        <xsd:element name="number" type="xsd:string"/>
                    </xsd:sequence>
                    <xsd:attribute name="type" type="xsd:string"/>
                </xsd:complexType>
            </xsd:element>
        </xsd:sequence>
    </xsd:complexType>
</xsd:schema>

Figure 65-27 XML Composite Collection Mapping

Description of "Figure 65-27 XML Composite Collection Mapping"

Example 65-49 Java for XML Composite Collection Mapping for a Collection Attribute

XMLCompositeCollectionMapping phoneNumbersMapping = new XMLCompositeCollectionMapping();
phoneNumbersMapping.setAttributeName("phoneNumbers");
phoneNumbersMapping.setXPath("phone-number");
phoneNumbersMapping.setReferenceClass(PhoneNumber.class);

Example 65-50 Java for XML Composite Collection Mapping for a Map Attribute

XMLCompositeCollectionMapping phoneNumbersMapping = new XMLCompositeCollectionMapping();
phoneNumbersMapping.setAttributeName("phoneNumbers");		
phoneNumbersMapping.setXPath("phone-number");
phoneNumbersMapping.setReferenceClass(PhoneNumber.class);
phoneNumbersMapping.useMapClass(HashMap.class, "getType");

See Chapter 70, "Configuring an XML Composite Collection Mapping" for more information.