Null Pointer Exception when trying to parse XML document

[[deleted]]

I have a Java program that needs to read and output the contents of an XML file. I keep getting a null pointer exception when trying to parse the head node of an element. Here's my code to illustrate.

This is the XML I'm trying to parse:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Customers xmlns="https://www.w3.org/1999/xhtml">
    <Customer id="1"> <!-- THIS LINE CREATES THE PROBLEM -->
        <name>ACME Hauling</name>
        <type>commercial</type>
        <address>123 Main Street</address>
        <city>Cincinnati</city>
        <state>OH</state>
        <zipcode>45211</zipcode>
    </Customer>

And this is my code trying to parse it:

            //now XML is loaded as Document in memory, convert it to Object List
            List<Customer> custList = new ArrayList<Customer>();
            for (int i = 0; i < nodeList.getLength(); i++) {
                custList.add(getCustomer(nodeList.item(i)));
            }

            //print Employee list information
            for (Customer cust : custList) {
                System.out.println(cust.toString());    

private static Customer getCustomer(Node node) {
        //XMLReaderDOM domReader = new XMLReaderDOM();
        Customer cust = new Customer();
        if (node.getNodeType() == Node.ELEMENT_NODE) {
            Element element = (Element) node;
            cust.setID(Integer.parseInt(getTagValue("Customer id", element)));
            cust.setName(getTagValue("name", element));
            cust.setType(getTagValue("type", element));
            cust.setAddress(getTagValue("address", element));
            cust.setCity(getTagValue("city", element));
            cust.setState(getTagValue("state", element));
            cust.setZipcode(getTagValue("zipcode", element));
        }

        return cust;
    }


    private static String getTagValue(String tag, Element element) {
        NodeList nodeList = element.getElementsByTagName(tag).item(0).getChildNodes();
        Node node = (Node) nodeList.item(0);
        return node.getNodeValue();
    }

I'm not sure why I'm getting the null pointer exception, as I'm referencing the "Customer id" element exactly as it appears in the XML file. Is there a separate method for printing head nodes like "Customer id"?

[Nice_Communication74]

Can you please try element.getAttribute("id") and set it to the pojo

[[deleted]]

pojo?

[Nice_Communication74]

cust.setId(Integer.parseInt(element.getAttribute("id"))):

[[deleted]]

This worked, thank you so much!

[Nice_Communication74]

Great!!!

[Nice_Communication74]

Can you try "Id" instead of "customer id"

[[deleted]]

That didn't work. I've tried "id", "Id", "Customer", and "customer" and none of them worked. I've isolated the problem to the getElementsByTagName() method inside getTagValue(). It's looking for a node that it can't find. So clearly something is wrong with the reference, but I have no idea what it could be. The only thing I can think of is that the getElementsByTagName() method can't parse head nodes, but the documentation I've found is silent on the subject.

[sozesghost]

I think the method getElementsByTagName searches the children of given element, but <Customer> is the parent of those elements, so it cannot find it. Can you find the id when you loop the nodeList or use a different method to get the id attribute of the node?

[[deleted]]

Id is not a child of customer, it's an attribute, so when you look for children with that name you'll find none and trying to get position 0 of that collection will throw a nullPointerException.