Finding differences in two XML files using XMLUnit

Question

How to check for only particular nodes and not all nodes for difference while using the DetailedDiff function of XMLUnit

this is my code:

public static void main(String[] args) 
    {
        //URL url1 = xmlunittest.class.getResource("MSHIS1.xml");
    //  URL url2 = xmlunittest.class.getResource("MSHIS.xml");

        Logger L = new Logger();

        FileReader fr1 = null;
        int countofdifferences = 0;
        FileReader fr2 = null;
        try {
            fr1 = new FileReader("MSHIS.xml");
            fr2 = new FileReader("MSHIS1.xml");
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        try {
            Diff diff = new Diff(fr1, fr2);
            L.writeToBVTLOG("Similar? " + diff.similar());
            L.writeToBVTLOG("Identical? " + diff.identical());


            DetailedDiff detDiff = new DetailedDiff(diff);
            List differences = detDiff.getAllDifferences();
            for (Object object : differences) {
                Difference difference = (Difference)object;
                L.writeToBVTLOG("------------------------");
                L.writeToBVTLOG(difference.toString());
                L.writeToBVTLOG("------------------------");

                countofdifferences++;
            }

        } catch (SAXException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }


        L.writeToBVTLOG(countofdifferences);
    }

But the thing is that, I just want the program to tell me if 4 particular nodes have undergone any changes. So how to get there from listing all the differences.

Answer 1

You can implement your own DifferenceListener that ignores some nodes (or only pays attention to some nodes) and tell XMLUnit to use it when checking differences. Here's a DifferenceListener that ignores any elements named "myelement":

public class IgnoreMyAttributeElements implements DifferenceListener()
{

      @Override
      public int differenceFound(Difference differenceIn)
      {
         Node controlNode = differenceIn.getControlNodeDetail().getNode();

         if(controlNode.getNodeType() == Node.ELEMENT_NODE)
         {
            if(controlNode.getLocalName().equals("myelement");
            {
               return DifferenceListener.RETURN_IGNORE_DIFFERENCE_NODES_IDENTICAL;
            }
         }

         return DifferenceListener.RETURN_ACCEPT_DIFFERENCE;
      }

      @Override
      public void skippedComparison(Node nodeIn, Node nodeIn2)
      {
         //don't care about these events
      }
}

Then pass it to the DetailedDiff:

DetailedDiff diff =  new DetailedDiff(XMLUnit.compareXML(oldXml, newXml));
diff.overrideDifferenceListener(new IgnoreMyAttributeElements());
List<?> allDifferences = diff.getAllDifferences();
//do something with differences