Complex XPaths using EclipseLink MOXy and JAXB - xpath

Question

I am currently using EclipseLink MOXy 2.4.1 and trying to update an element's value via XPaths.
The input used is :
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<expenseReport>
<user>
<userName>Sanaulla</userName>
</user>
<items>
<item>
<itemName>Seagate External HDD</itemName>
<purchasedOn>August 24, 2010</purchasedOn>
<amount>6776.5</amount>
</item>
<item>
<itemName>External HDD</itemName>
<purchasedOn>August 24, 2010</purchasedOn>
<amount>677336.5</amount>
</item>
</items>
</expenseReport>
The XSD is
<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="expenseReport" type="ExpenseT"/>
<xs:complexType name="ExpenseT">
<xs:sequence>
<xs:element name="user" type="UserT"/>
<xs:element name="items" type="ItemListT"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="UserT">
<xs:sequence>
<xs:element name="userName" type="xs:string"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="ItemListT">
<xs:sequence>
<xs:element name="item" type="ItemT" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="ItemT">
<xs:sequence>
<xs:element name="itemName" type="xs:string"/>
<xs:element name="purchasedOn" type="xs:string"/>
<xs:element name="amount" type="xs:decimal"/>
</xs:sequence>
</xs:complexType>
</xs:schema>
And my Java code is :
JAXBContext context = JAXBContext.newInstance("sample.jaxb.xsd");
JAXBElement<ExpenseT> element = (JAXBElement<ExpenseT>)unmarshaller.unmarshal(new File("resources/sample_before.xml"));
ExpenseT expenseReport = element.getValue();
context.setValueByXPath(expenseReport, "items/item[1]/amount/text()", null, "100.11");
/** Marshalling code **/
I have my java classes created from the XSD using Moxy's tool "jaxb-compiler.cmd".
As you can see from the above code, I am trying to set the amount of 1st item to "100.11". But it doesn't set the value, nor does it throw any exception.
I tried setting the username above using XPath like this
context.setValueByXPath(expenseReport, "user/userName/text()", null, "ABC");
And, it does set/update the value properly.
Can you please advise on how can I set values for complex XPaths with Predicates? Something like this :
items/item[itemName='Seagate External HDD']/amount

Answer 1

We recently fixed a bug in our EclipseLink 2.4.2 and 2.5.0 streams related to setting values in which the XPath contains a postional indicator (ie "foo[1]/bar[2]/text()"). You can download a nightly build from the following link:
http://www.eclipse.org/eclipselink/downloads/nightly.php
You can use predicates in mappings with #XmlPath (see: http://blog.bdoughan.com/2011/03/map-to-element-based-on-attribute-value.html), but we currently don't supports this with our setValueByXPath call. Could you open an enhancement