Annotation Type XmlPath
XPath based mapping is what allows an existing object model to be mapped
to an existing XML schema. The @XmlPath
annotation is the means by
which XPath based mapping is achieved.
@XmlPath
to Add a Grouping Element
Sometimes grouping elements are added to your document to organise data.
JAXB has this concept for collection properties in the form of
@XmlElementWrapper
. Here we'll use @XmlPath
for
non-collection properties. In this case we'll nest the billing/shipping
address data within the "contact-info" element.
import jakarta.xml.bind.annotation.*; import org.eclipse.persistence.oxm.annotations.XmlPath; @XmlRootElement @XmlAccessorType(XmlAccessType.FIELD) public class Customer { @XmlPath("contact-info/billing-address") private Address billingAddress; @XmlPath("contact-info/shipping-address") private Address shippingAddress; }This will produce XML like:
<xmp>
<customer>
<contact-info>
<billing-address>
<street>1 Billing Street</street>
</billing-address>
<shipping-address>
<street>2 Shipping Road</street>
</shipping-address>
</contact-info>
</customer>
</xmp>
Example 2 - Using @XmlPath
to Map by Position
Normally in JAXB elements with the same name must be mapped to a collection property. Using the @XmlPath extension you map non-collection properties to a repeated element by index.
import jakarta.xml.bind.annotation.*; import org.eclipse.persistence.oxm.annotations.XmlPath; @XmlRootElement @XmlAccessorType(XmlAccessType.FIELD) public class Customer { @XmlPath("address[1]") private Address billingAddress; @XmlPath("address[2]") private Address shippingAddress; }This will produce XML like:
<xmp>
<customer>
<address>
<street>1 Billing Street</street>
</address>
<address>
<street>2 Shipping Road</street>
</address>
</customer>
</xmp>
Example 3 - Using @XmlPath
to Map Two Objects to the Same Node
We have seen how @XmlPath
can be used to expand the structure by
adding a grouping element. @XmlPath
can also be used to collapse the
structure by mapping two objects to the same node.
import jakarta.xml.bind.annotation.*; import org.eclipse.persistence.oxm.annotations.XmlPath; @XmlRootElement @XmlAccessorType(XmlAccessType.FIELD) public class Customer { @XmlPath(".") private Address billingAddress; private Address shippingAddress; }This will produce XML like:
<xmp>
<customer>
<street>1 Billing Street</street>
<shippingAddress>
<street>2 Shipping Road</street>
</shippingAddress>
</customer>
</xmp>
-
Required Element Summary
-
Element Details
-
value
String valueThe XPath for this property. A subset of the XPath specification may be used to specify mappings. The following concepts are supported:
- Attribute - "@id"
- Element - "address"
- Element by Position - "address[1]"
- Element by Predicate - "address[@type='mailing']"
- Element Text - "name/text()"
- Text - "text()"
- Self - "."
- Combination - "personal-info/name[2]/text()"
For namespace qualified nodes, the prefixes defined in the XmlNs annotations can be used to qualify the XPath fragments. Unqualified fragments will assumed to be in the namespace specified using @XmlSchema.
ExampleAssuming the following namespace information has been set up using the @XmlSchema annotation:
@XmlSchema(namespace = "http://www.example.org/FOO", xmlns = {@XmlNs(prefix="ns", namespaceURI="http://www.example.com/BAR")}, elementFormDefault = XmlNsForm.QUALIFIED) package org.example; import jakarta.xml.bind.annotation.*;
Then the following XPath:
@XmlPath("contact-info/ns:address/@id")
Will be qualified as:
- contact-info - in "http://www.example.org/FOO" namespace.
- address - in "http://www.example.com/BAR" namespace.
- @id - in no namespace.
- See Also:
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