Issue with comparing XML documents in Java using oracle.xml.differ.XMLDiff

Question

I have an issue trying to compare 2 XML documents in Java, using oracle.xml.differ.XMLDiff. The code is fully implemented and I expected it to be working fine, until I discovered an attribute change is not picked up in some instances. To demonstrate this, I have the following:

Setup:

DOMParser parser = new DOMParser();
parser.setPreserveWhitespace(false);
parser.parse(isCurrent);
XMLDocument currentXmlDoc = parser.getDocument();

parser.parse(isPrior);
XMLDocument priorXmlDoc = parser.getDocument();

XMLDiff xmlDiff = new XMLDiff();
xmlDiff.setDocuments(currentXmlDoc, priorXmlDoc);

In the first case, the attribute change in Strike is picked up fine. I have the following 2 XML files:

XML1

<Periods>
   <Period Start="2011-03-28" End="2011-04-17" AverageStart="" AverageEnd="" Notional="6000000.0000" OptionType="Swap" Payment="2011-04-19" Strike="72.0934800" Underlying="ZA" ResetStrike="No" ResetNotional="No" QuotingDate="2011-04-17" Multiplier="1.000000" PlusConstant="0.000000" StopLossPercent="" StopLossLevel=""/>
</Periods>

XML2

<Periods>
   <Period Start="2011-03-28" End="2011-04-17" AverageStart="" AverageEnd="" Notional="6000000.0000" OptionType="Swap" Payment="2011-04-19" Strike="0.0000000" Underlying="ZA" ResetStrike="No" ResetNotional="No" QuotingDate="2011-04-17" Multiplier="1.000000" PlusConstant="0.000000" StopLossPercent="" StopLossLevel=""/>
</Periods>

In the second case, the attribute change in Strike is not picked up. I have the following 2 XML files:

XML1

<Periods>
    <Period Start="2011-03-28" End="2011-04-30" Payment="2011-05-02" Notional="5220000.000000" Strike="176.201900" StopLossPercent="" StopLossLevel=""/>
</Periods>

XML2

<Periods>
    <Period Start="2011-03-28" End="2011-04-30" Payment="2011-05-02" Notional="5220000.000000" Strike="0.000000" StopLossPercent="" StopLossLevel=""/>
</Periods>

Does anyone know if I'm doing something wrong, or is there a bug in the XMLDiff package?

Alternatively, does anyone know a different tool that can be used in the same way, just identifying differences in nodes and attributes between XML files, regardless of the order?

Thanks, Milena

UPDATE: As it's extremely time-consuming to get new external packages approved for use in our system, in the ideal case I'd like to find a solution to making oracle.xml.differ.XMLDiff work. Obviously if there really is a bug and this can't be bypassed I'll consider other tools.

UPDATE 2: Since nobody seems to know about the XMLDiff bug, I'll try implementing the suggested XMLUnit package, it should do the trick.

Answer 1

In a unit test i'm using org.custommonkey.xmlunit.Diff for comparing xml content. See http://xmlunit.sourceforge.net/api/org/custommonkey/xmlunit/Diff.html

I'm comparing xml strings but you can also compare xml w3c documents. I hope you can convert your XMLDocument to either a String of an org.w3c.dom.Document.

my testcase looks like this:

String actualXML = SomeClass.getElement().asXML();
String expectedXML = IOUtils.toString(this.getClass().getResourceAsStream("/expected.xml"));

org.custommonkey.xmlunit.Diff myDiff = new Diff(StringUtils.deleteWhitespace(expectedXML), StringUtils.deleteWhitespace(actualXML));
assertTrue(MessageFormat.format("XML must be simular: {0}\nActual XML:\n{1}\n", myDiff, actualXML), myDiff.similar());

p.s. I also use the apache commons StringUtils.deleteWhitespace() method, cause i'm not interested in white space differences.