TestDOM.java Source code

Introduction

Here is the source code for TestDOM.java

Source

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;
import org.w3c.dom.Text;

public class TestDOM {
    public static void main(String[] args) throws Exception {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder parser = factory.newDocumentBuilder();
        Document document = parser.parse("zooinventory.xml");
        Element inventory = document.getDocumentElement();
        NodeList animals = inventory.getElementsByTagName("Animal");

        System.out.println("Animals = ");
        for (int i = 0; i < animals.getLength(); i++) {
            String name = DOMUtil.getSimpleElementText((Element) animals.item(i), "Name");
            String species = DOMUtil.getSimpleElementText((Element) animals.item(i), "Species");
            System.out.println("  " + name + " (" + species + ")");
        }

        Element foodRecipe = DOMUtil.getFirstElement((Element) animals.item(1), "FoodRecipe");
        String name = DOMUtil.getSimpleElementText(foodRecipe, "Name");
        System.out.println("Recipe = " + name);
        NodeList ingredients = foodRecipe.getElementsByTagName("Ingredient");
        for (int i = 0; i < ingredients.getLength(); i++)
            System.out.println("  " + DOMUtil.getSimpleElementText((Element) ingredients.item(i)));
    }
}

class DOMUtil {
    public static Element getFirstElement(Element element, String name) {
        NodeList nl = element.getElementsByTagName(name);
        if (nl.getLength() < 1)
            throw new RuntimeException("Element: " + element + " does not contain: " + name);
        return (Element) nl.item(0);
    }

    public static String getSimpleElementText(Element node, String name) {
        Element namedElement = getFirstElement(node, name);
        return getSimpleElementText(namedElement);
    }

    public static String getSimpleElementText(Element node) {
        StringBuffer sb = new StringBuffer();
        NodeList children = node.getChildNodes();
        for (int i = 0; i < children.getLength(); i++) {
            Node child = children.item(i);
            if (child instanceof Text)
                sb.append(child.getNodeValue());
        }
        return sb.toString();
    }
}

//File: zooinventory.xml
/*<?xml version="1.0" encoding="UTF-8"?>
    
<Element2>
  <Element3 animalClass="mammal">
<Name>A</Name>
<Species>B</Species>
<Habitat>C</Habitat>
<Food>D</Food>
<Temperament>E</Temperament>
<Weight>1</Weight>
  </Element3>
  <Element3 animalClass="mammal">
<Name>F</Name>
<Species>G</Species>
<Habitat>H</Habitat>
<ElementA>
  <Name>I</Name>
  <Ingredient>I1</Ingredient>
  <Ingredient>I2</Ingredient>
  <Ingredient>I2</Ingredient>
</ElementA>
<Temperament>J</Temperament>
<Weight>4</Weight>
  </Element3>
</Element2>
*/