SAP PI/PO: How to Parse Raw XML String to XML Data Type

[#1]

I would like to implement a WS Scenario in SAP PI. The WS response is a string which contains a RAW XML, something like this:

<?xml version="1.0" encoding="utf-8"?>
<string xmlns="http://test-xml.com/">
  <ITEM><ATTRIBUTE>TEST VALUE1</ATTRIBUTE></ITEM>
  <ITEM><ATTRIBUTE>TEST VALUE2</ATTRIBUTE></ITEM>
</string>

(The editor is replacing the raw opening and closing tags &LESS_THAN; with the symbol < representation)

I would need to parse the raw XML to a XML PI DataType, which would have an ITEM node (0..unbounded) with its attributes sub-nodes as well.

I have been researching about Java Mapping and XSLT Transformation, but I'm not sure which way to go.