Having trouble reading data from xml file

Question

The object of my code is to create a shoppinglist from recipes stored in an xml file.

Im having trouble with how to get the data from the xml file and convert it into a list.

To start of I would love some help to just be able to print a simple list of the ingredients in the first recipe.

Heres my XML file:

<?xml version="1.0" encoding="UTF-8"?>
    <Drinks>
        <Drink id="Whiskey Sour">
            <ingredients group="Alkohol">
                <ingredient name="Whiskey" quantity="5" unit="cl">Whiskey</ingredient>
            </ingredients>
            <ingredients group="Mixer">
                <ingredient name="Friskpresset Citron" quantity="4" unit="cl">Friskpresset Citron</ingredient>
                <ingredient name="Sukkersirup" quantity="3" unit="cl">Sukkersirup</ingredient>
                <ingredient name="Æggehvide" quantity="½" unit="cl">Æggehvide</ingredient>
                <ingredient name="Angustura" quantity="2" unit="dash">Angustura</ingredient>
            </ingredients>
        </Drink>
        <Drink id="White Russian Frangelico">
            <ingredients group="Alkohol">
                <ingredient name="Vodka" quantity="3" unit="cl">Vodka</ingredient>
                <ingredient name="Kahlua" quantity="2" unit="cl">Kahlua</ingredient>
                <ingredient name="Frangelico" quantity="1" unit="cl">Frangelico</ingredient>
            </ingredients>
            <ingredients group="Mixer">
                <ingredient name="Sødmælk" quantity="3" unit="cl">Sødmælk</ingredient>
            </ingredients>
        </Drink>
        <Drink id="Espresso Martini">
            <ingredients group="Alkohol">
                <ingredient name="Vodka" quantity="3" unit="cl">Vodka</ingredient>
                <ingredient name="Kahlua" quantity="2" unit="cl">Kahlua</ingredient>
            </ingredients>
            <ingredients group="Mixer">
                <ingredient name="Kaffe" quantity="2" unit="cl">Kaffe</ingredient>
                <ingredient name="Sukkersirup" quantity="1" unit="cl">Sukkersirup</ingredient>
            </ingredients>
        </Drink>
    </Drinks>

And here is my code:

import java.io.File;
import org.w3c.dom.*;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

public class CreateListOfGoods{

    public static void main (String argv[]) {
        try {
            DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
            Document doc = docBuilder.parse (new File("src/Kartotek.xml")); 
            // normalize text representation
            doc.getDocumentElement ().normalize ();
            System.out.println ("Root element of the doc is " + doc.getDocumentElement().getNodeName());    

            //Prints the amount of drinks in the database
            NodeList listOfDrinksNode = doc.getElementsByTagName("Drink");
            int totalDrinks = listOfDrinksNode.getLength();
            System.out.println("Total no of Drinks : " + totalDrinks);

            for(int s=0; s<listOfDrinksNode.getLength(); s++) {     
                Node listOfIngredientsNode = listOfDrinksNode.item(s);
                if(listOfIngredientsNode.getNodeType() == Node.ELEMENT_NODE) {
                    System.out.println("Virker if?");
                    //--------
                    NodeList alkoholList =  doc.getElementsByTagName("Ingredient");
                    Element alkoholElement = (Element)alkoholList.item(0);
                    String PrintAlkohol = alkoholElement.getTagName();

                    System.out.println(PrintAlkohol);
                }
            }
        } catch (SAXParseException err) {
            System.out.println ("** Parsing error" + ", line " + err.getLineNumber () + ", uri " + err.getSystemId ());
            System.out.println(" " + err.getMessage ());
        } catch (SAXException e) {
            Exception x = e.getException ();
            ((x == null) ? e : x).printStackTrace ();
        } catch (Throwable t) {
            t.printStackTrace ();
        }
    }
}

Some of the variables are in Danish, but the code should be understandable. Hope some of you can guide me in the rigth direction

Answer 1

I've slightly modified the code. Now, it gathers all ingredients into list which is printed in the end of the program. It does it in 3 steps: 1) find all drinks; 2) find all ingredients groups; 3) find all ingredients in those groups and add them to list.

import org.w3c.dom.*;
import java.util.List;
import java.util.ArrayList;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;


public class CreateListOfGoods{

public static void main (String argv[]) {
    try {
        List<String> listOfIngredients = new ArrayList<String>();
        String INGREDIENTS_TAG_NAME = "ingredients";
        String INGREDIENT_TAG_NAME = "ingredient";
        String DRINK_TAG_NAME = "Drink";
        String GROUP_ATTRIBUTE_NAME = "group";
        String INGREDIENT_NAME_ATTRIBUTE_NAME = "name";

        DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
        Document doc = docBuilder.parse (new java.io.File("src/Kartotek.xml"));
        // normalize text representation
        doc.getDocumentElement ().normalize ();
        System.out.println ("Root element of the doc is " + doc.getDocumentElement().getNodeName());


        //Prints the amount of drinks in the database
        NodeList listOfDrinksNode = doc.getElementsByTagName(DRINK_TAG_NAME);
        int totalDrinks = listOfDrinksNode.getLength();
        System.out.println("Total no of Drinks : " + totalDrinks);

        for(int s=0; s<listOfDrinksNode.getLength(); s++) {

            // Find all ingredients groups
            NodeList groupNodes = listOfDrinksNode.item(s).getChildNodes();
            for(int i = 0; i < groupNodes.getLength(); i++) {
                if(groupNodes.item(i).getNodeType() == Node.ELEMENT_NODE) {
                    Element groupElement = (Element)groupNodes.item(i);
                    if(groupElement.getTagName().equals(INGREDIENTS_TAG_NAME)) {
                        System.out.println(String.format("group: %s", groupElement.getAttribute(GROUP_ATTRIBUTE_NAME)));

                        // Find all ingredients in group
                        NodeList ingredientNodes = groupElement.getChildNodes();
                        for(int j = 0; j < ingredientNodes.getLength(); j++) {
                            if(ingredientNodes.item(j).getNodeType() == Node.ELEMENT_NODE) {
                                Element ingredientElement = (Element)ingredientNodes.item(j);
                                if(ingredientElement.getTagName().equals(INGREDIENT_TAG_NAME)) {
                                    String ingredientName = ingredientElement.getAttribute(INGREDIENT_NAME_ATTRIBUTE_NAME);
                                    System.out.println(String.format("Ingredient name: %s", ingredientName));
                                    listOfIngredients.add(ingredientName);
                                }
                            }
                        }
                    }

                }
            }

        }

        System.out.println("All ingredients: " + listOfIngredients.toString());
    }catch (SAXParseException err) {
        System.out.println ("** Parsing error" + ", line " + err.getLineNumber () + ", uri " + err.getSystemId ());
        System.out.println(" " + err.getMessage ());

    }catch (SAXException e) {
        Exception x = e.getException ();
        ((x == null) ? e : x).printStackTrace ();

    }catch (Throwable t) {
        t.printStackTrace ();
    }
}
}