@Target(value={FIELD,METHOD})
@Retention(value=RUNTIME)
public @interface 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 javax.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:
@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 javax.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:
@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 javax.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:
Modifier and Type | Required Element and Description |
---|---|
java.lang.String |
value
The XPath for this property.
|
public abstract java.lang.String value
The XPath for this property. A subset of the XPath specification may be used to specify mappings. The following concepts are supported:
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 javax.xml.bind.annotation.*;
Then the following XPath:
@XmlPath("contact-info/ns:address/@id")
Will be qualified as: