Better way to parse xml

Question

I\'ve been parsing XML like this for years, and I have to admit when the number of different element becomes larger I find it a bit boring and exhausting to do, here is what I m

Answer 1

There is another library which supports more compact XML parsing, RTXML. The library and its documentation is on rasmustorkel.com. I implemented the parsing of the file in the original question and I am including the complete program here:

package for_so;

import java.io.File;
import java.util.ArrayList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import rasmus_torkel.xml_basic.read.TagNode;
import rasmus_torkel.xml_basic.read.XmlReadOptions;
import rasmus_torkel.xml_basic.read.impl.XmlReader;

public class Q15626686_ReadOrder
{
    public static class Order
    {
        public final Date            _date;
        public final int             _customerId;
        public final String          _customerName;
        public final ArrayList _itemAl;

        public
        Order(TagNode node)
        {
            _date = (Date)node.nextStringMappedFieldE("Date", Date.class);
            _customerId = (int)node.nextIntFieldE("CustomerId");
            _customerName = node.nextTextFieldE("CustomerName");
            _itemAl = new ArrayList();
            boolean finished = false;
            while (!finished)
            {
                TagNode itemNode = node.nextChildN("Item");
                if (itemNode != null)
                {
                    Item item = new Item(itemNode);
                    _itemAl.add(item);
                }
                else
                {
                    finished = true;
                }
            }
            node.verifyNoMoreChildren();
        }
    }

    public static final Pattern DATE_PATTERN = Pattern.compile("^(\\d\\d\\d\\d)\\/(\\d\\d)\\/(\\d\\d)$");

    public static class Date
    {
        public final String _dateString;
        public final int    _year;
        public final int    _month;
        public final int    _day;

        public
        Date(String dateString)
        {
            _dateString = dateString;
            Matcher matcher = DATE_PATTERN.matcher(dateString);
            if (!matcher.matches())
            {
                throw new RuntimeException(dateString + " does not match pattern " + DATE_PATTERN.pattern());
            }
            _year = Integer.parseInt(matcher.group(1));
            _month = Integer.parseInt(matcher.group(2));
            _day = Integer.parseInt(matcher.group(3));
        }
    }

    public static class Item
    {
        public final int      _itemId;
        public final String   _itemName;
        public final Quantity _quantity;

        public
        Item(TagNode node)
        {
            _itemId = node.nextIntFieldE("ItemId");
            _itemName = node.nextTextFieldE("ItemName");
            _quantity = new Quantity(node.nextChildE("Quantity"));
            node.verifyNoMoreChildren();
        }
    }

    public static class Quantity
    {
        public final int _unitSize;
        public final int _unitQuantity;

        public
        Quantity(TagNode node)
        {
            _unitSize = node.attributeIntD("unit", 1);
            _unitQuantity = node.onlyInt();
        }
    }

    public static void
    main(String[] args)
    {
        File xmlFile = new File(args[0]);
        TagNode orderNode = XmlReader.xmlFileToRoot(xmlFile, "Order", XmlReadOptions.DEFAULT);
        Order order = new Order(orderNode);
        System.out.println("Read order for " + order._customerName + " which has " + order._itemAl.size() + " items");
    }
}

You will notice that the retrieval functions end in N, E or D. They refer to what to do when the desired data item is not there. N stands for return Null, E stands for throw Exception and D stands for use Default.