Question

I would like to read an xml file. I’ ve found an example which is good until the xml element doesn’t have any attributes. Of course i’ve tried to look after how could I read attributes, but it doesn’t works.

XML for example

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<car>
<properties>
<test h="1.12" w="4.2">
<colour>red</colour>
</test>
</properties>
</car>

Java Code:

public void readXML(String file) {
    try {

        File fXmlFile = new File(file);
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory
                .newInstance();
        DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
        doc = dBuilder.parse(fXmlFile);
        doc.getDocumentElement().normalize();

        for (int temp = 0; temp < nList.getLength(); temp++) {

            Node nNode = nList.item(temp);
            if (nNode.getNodeType() == Node.ELEMENT_NODE) {

                Element eElement = (Element) nNode;

                System.out.println("test : "
                        + getTagValue("test", eElement));
                System.out.println("colour : " + getTagValue("colour", eElement));

            }
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
}

public String getTagValue(String sTag, Element eElement) {
    NodeList nlList = eElement.getElementsByTagName(sTag).item(0)
            .getChildNodes();


    Node nValue = (Node) nlList.item(0);
            System.out.println(nValue.hasAttributes());

    if (sTag.startsWith("test")) {
        return eElement.getAttribute("w");

    } else {
        return nValue.getNodeValue();
    }

}

Output:

false

test :

false

colour : red

My problem is, that i can’t print out the attributes. How could i get the attributes?

Answer 1

There is alot wrong with your code; undeclared variables and a seemingly crazy algorithm. I rewrote it and it works:

import java.io.File;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public final class LearninXmlDoc
{
    private static String getTagValue(final Element element)
    {
        System.out.println(element.getTagName() + " has attributes: " + element.hasAttributes());

        if (element.getTagName().startsWith("test"))
        {
            return element.getAttribute("w");

        }
        else
        {
            return element.getNodeValue();
        }
    }

    public static void main(String[] args)
    {
        final String fileName = "c:\\tmp\\test\\domXml.xml";

        readXML(fileName);
    }

    private static void readXML(String fileName)
    {
        Document document;
        DocumentBuilder documentBuilder;
        DocumentBuilderFactory documentBuilderFactory;
        NodeList nodeList;
        File xmlInputFile;

        try
        {
            xmlInputFile = new File(fileName);
            documentBuilderFactory = DocumentBuilderFactory.newInstance();
            documentBuilder = documentBuilderFactory.newDocumentBuilder();
            document = documentBuilder.parse(xmlInputFile);
            nodeList = document.getElementsByTagName("*");

            document.getDocumentElement().normalize();

            for (int index = 0; index < nodeList.getLength(); index++)
            {
                Node node = nodeList.item(index);
                if (node.getNodeType() == Node.ELEMENT_NODE)
                {
                    Element element = (Element) node;

                    System.out.println("\tcolour : " + getTagValue(element));
                    System.out.println("\ttest : " + getTagValue(element));
                    System.out.println("-----");
                }
            }
        }
        catch (Exception exception)
        {
            exception.printStackTrace();
        }
    }
}