Question

Having a bit of trouble parsing xml with dom and DocumentBuilder. I’m able to get it working, but I guess I get a bit confused with all the child nodes, etc.

Here’s the XML I’m working with:

<?xml version="1.0" encoding="utf-8"?>
<LabTests>
    <LabTest type="specialty" name="Anti-FXa activity" id="antiFXa" order="16">
        <values unit="U/mL" default="N/A">
            <value type="increased" val="0">
                <conditions>
                    <condition>Heparin effect</condition>
                </conditions>
            </value>
            <value type="normal" val="">
                <conditions></conditions>
            </value>
            <value type="decreased" val="">
                <conditions></conditions>
            </value>
        </values>
    </LabTest>
    <LabTest type="general" name="aPTT" id="aPTT" order="">
        <values unit="secs" default="N/A">
            <value type="increased" val="">
                <conditions>
                    <condition>Acquired hemophilia</condition>
                    <condition>Acquired vWD</condition>
                    <condition>DIC</condition>
                    <condition>Dysfibrinogenemia</condition>
                    <condition>FI deficiency</condition>
                    <condition>FII deficiency</condition>
                    <condition>FII/IIa inhibitors</condition>
                    <condition>FIX deficiency</condition>
                    <condition>FIX inhibitors</condition>
                    <condition>FV deficiency</condition>
                    <condition>FV inhibitors</condition>
                    <condition>FVIII deficiency</condition>
                    <condition>FX deficiency</condition>
                    <condition>FX inhibitors</condition>
                    <condition>FXI deficiency</condition>
                    <condition>FXI inhibitors</condition>
                    <condition>FXII deficiency</condition>
                    <condition>FXII inhibitors</condition>
                    <condition>Heparin effect</condition>
                    <condition>Liver disease effect</condition>
                    <condition>Lupus anticoagulant</condition>
                    <condition>Monoclonal gammopathy</condition>
                    <condition>Vitamin K deficiency</condition>
                    <condition>vWD type 1</condition>
                    <condition>vWD type 2</condition>
                    <condition>vWD type 3</condition>
                    <condition>Warfarin effect</condition>
                </conditions>
            </value>
            <value type="normal" val="">
                <conditions>
                    <condition>DIC</condition>
                    <condition>Dysfibrinogenemia</condition>
                    <condition>FVII deficiency</condition>
                    <condition>FXIII deficiency</condition>
                    <condition>FVII inhibitors</condition>
                    <condition>Liver disease effect</condition>
                    <condition>Lupus anticoagulant</condition>
                    <condition>Monoclonal gammopathy</condition>
                    <condition>Vitamin K deficiency</condition>
                    <condition>vWD type 1</condition>
                    <condition>vWD type 2</condition>
                    <condition>vWD type 3</condition>
                    <condition>Warfarin effect</condition>
                </conditions>
            </value>
            <value type="decreased" val="">
                <conditions>
                    <condition>DIC</condition>
                </conditions>
            </value>
        </values>
    </LabTest>
</LabTests>

what I’m trying to do is grab hold of each LabTest element and, within each of those elements, grab hold of the value elements (and grab the value of type) and, within the value element, grab hold of all of the condition elements.

In the end, I want something like a Map<String, HashMap<String, ArrayList<String>>, where the String is the LabTest name and the HashMap uses the type (e.g. decreased, increased, etc) for the key and then fills up the ArrayList with the conditions for that value type.

Confusing enough?

Basically, I just need an example, I think, of how to loop through and grab each LabTest with its “value” elements, and each of the “condition” elements under those “value” elements.

Answer 1

That should work as you described:

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();

Document doc = builder.parse("input.xml");

NodeList labTestList = doc.getElementsByTagName("LabTest");
for (int i = 0; i < labTestList.getLength(); ++i)
{
    Element labTest = (Element) labTestList.item(i);
    String labTestType = labTest.getAttribute("type");

    NodeList valueList = labTest.getElementsByTagName("value");
    for (int j = 0; j < valueList.getLength(); ++j)
    {
        Element value = (Element) valueList.item(j);
        String valueType = value.getAttribute("type");

        NodeList conditionList = value.getElementsByTagName("condition");
        for (int k = 0; k < conditionList.getLength(); ++k)
        {
            Element condition = (Element) conditionList.item(k);
            String conditionText = condition.getFirstChild().getNodeValue();
        }
    }
}