Querying Objects by XPath

In addition to using conventional Java access methods to get and set your object's values, EclipseLink MOXy also allows you to access values using an XPath statement. There are special APIs on EclipseLink's JAXBContext to allow you to get and set values by XPath.

For example, consider the following XML document:

<customer id="1141">
   <first-name>Jon</first-name>
   <last-name>Smith</last-name>
   <phone-number>
      <area-code>515</area-code>
      <number>2726652</number>
   </phone-number>
</customer>
 

Typical application code might look something like this:

Customer customer = (Customer) jaxbContext.createUnmarshaller().unmarshal(instanceDoc);
...
int customerId = customer.getId();
customer.setFirstName("Bob");
customer.getPhoneNumber().setAreaCode("555");
...
jaxbContext.createMarshaller().marshal(customer, System.out);
 

You could instead use XPath to access these values:

Customer customer = (Customer) jaxbContext.createUnmarshaller().unmarshal(instanceDoc);
...
int customerId = jaxbContext.getValueByXPath(customer, "@id", null, Integer.class);
jaxbContext.setValueByXPath(customer, "first-name/text()", null, "Bob");
jaxbContext.setValueByXPath(customer, "phone-number/area-code/text()", null, "555");
...
jaxbContext.createMarshaller().marshal(customer, System.out);