How to use the SAX parser to save the only child elements and storing them in the collection?

Question

I have a xml file:

<shop>
    <department number= "1" name="unknown">
        <product id="1"/>
        <product id="2"/>
        <product id="3"/>
    </department>
    <department number= "2" name="unknown">
        <product id="4"/>
        <product id="5"/>
        <product id="6"/>
    </department>
    <department number= "3" name="unknown">
        <.../>
    </department>
</shop>

To save the data parsing, I created a class Department and a collection ArrayList <Department>, to keep these classes there. The class looks like this:

class Department {
    String number;
    String name;
    ArrayList<Integer> productId = new ArrayList<>(); // collection for storage "attribut id of product"
    //constructor
    public Department(String n, String na, ArrayList<Integer> pr) {
        this.number = n;
        this.name = na;
        this.productId = pr;
    }
}

How do I set the SAX-parser to work in each instance of the class Departament got only his daughter tags product id and placed in a particular ArrayList <Integer>?

Answer 1

Try this.

public class Department {
    final String number;
    final String name;
    final List<Integer> products = new ArrayList<>();

    Department(String number, String name) {
        this.number = number;
        this.name = name;
    }
}

And

File input = new File("shop.xml");
SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
List<Department> departments = new ArrayList<>();
parser.parse(input, new DefaultHandler() {
    Department department = null;
    @Override
    public void startElement(String uri,
        String localName, String qName, Attributes attributes)
        throws SAXException {
        switch (qName) {
        case "department":
            department = new Department(
                attributes.getValue("number"),
                attributes.getValue("name"));
            departments.add(department);
            break;
        case "product":
            department.products.add(Integer.parseInt(attributes.getValue("id")));
            break;
        }
    }
});