Chamar um aquivo xml dentro do Java (Castor XML)

import java.util.Vector;
import java.util.Enumeration;

public class MyOrder {

    private String _ref;
    private ClientData _client;
    private Vector _items;
    private float _total;

    public void setReference(String ref) {
        _ref = ref;
    }

    public String getReference() {
        return _ref;
    }

    public void setClientData(ClientData client) {
        _client = client;
    }

    public ClientData getClientData() {
        return _client;
    }

    public void setItemsList(Vector items) {
        _items = items;
    }

    public Vector getItemsList() {
        return _items;
    }


    public void setTotal(float total) {
        _total = total;
    }

    public float getTotal() {
        return _total;
    }

    // Do some processing on the data
    public float getTotalPrice() {
        float total = 0.0f;

        for (Enumeration e = _items.elements() ; e.hasMoreElements() ;) {
            Item item = (Item) e.nextElement();
            total += item._quantity * item._unitPrice;
        }

        return total;
    }
}

public class ClientData {

    private String _name;
    private String _address;

    public void setName(String name) {
        _name = name;
    }

    public String getName() {
        return _name;
    }

    public void setAddress(String address) {
        _address = address;
    }

    public String getAddress() {
        return _address;
    }
}

public class Item {
    public String _reference;
    public int    _quantity;
    public float  _unitPrice;
    public String _description;
}

<?xml version="1.0"?>
<!DOCTYPE mapping PUBLIC "-//EXOLAB/Castor Mapping DTD Version 1.0//EN"
                         "http://castor.org/mapping.dtd">

<mapping>
  <class name="MyOrder">
    <map-to xml="Order"/>

    <field name="Reference"
           type="java.lang.String">
      <bind-xml name="reference" node="attribute"/>
    </field>

    <field name="Total"
           type="float">
      <bind-xml name="total-price" node="attribute"/>
    </field>

    <field name="ClientData"
           type="ClientData">
      <bind-xml name="Client"/>
    </field>

    <field name="ItemsList"
           type="Item"
              collection="vector">
      <bind-xml name="Item"/>
    </field>
  </class>

  <class name="ClientData">
    <field name="Name"
           type="java.lang.String">
      <bind-xml name="Name" node="element"/>
    </field>

    <field name="Address"
           type="java.lang.String">
      <bind-xml name="Address" node="element"/>
    </field>
  </class>

  <class name="Item">
    <field name="_reference"
           type="java.lang.String"
           direct="true">
      <bind-xml name="reference" node="attribute"/>
    </field>

    <field name="_quantity"
           type="integer"
           direct="true">
      <bind-xml name="Quantity" node="element"/>
    </field>

    <field name="_unitPrice"
           type="float"
           direct="true">
      <bind-xml name="UnitPrice" node="element"/>
    </field>

    <field name="_description"
           type="string"
           direct="true">
      <bind-xml name="Description" node="element"/>
    </field>
  </class>

</mapping>

import org.exolab.castor.mapping.Mapping;
import org.exolab.castor.mapping.MappingException;

import org.exolab.castor.xml.Unmarshaller;
import org.exolab.castor.xml.Marshaller;

import java.io.IOException;
import java.io.FileReader;
import java.io.OutputStreamWriter;

import org.xml.sax.InputSource;

public class main {

    public static void main(String args[]) {

        Mapping      mapping = new Mapping();

        try {
            // 1. Load the mapping information from the file
            mapping.loadMapping( "mapping.xml" );

            // 2. Unmarshal the data
            Unmarshaller unmar = new Unmarshaller(mapping);
            MyOrder order = (MyOrder)unmar.unmarshal(new InputSource(new FileReader("order.xml")));

            // 3. Do some processing on the data
            float total = order.getTotalPrice();
            System.out.println("Order total price = " + total);
            order.setTotal(total);

            // 4. marshal the data with the total price back and print the XML in the console
            Marshaller marshaller = new Marshaller(new OutputStreamWriter(System.out));
            marshaller.setMapping(mapping);
            marshaller.marshal(order);

        } catch (Exception e) {
            System.out.println(e);
            return;
        }
    }
}

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
	at org.exolab.castor.mapping.Mapping.<clinit>(Mapping.java:70)
	at pack.Main.main(Main.java:14)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClassInternal(Unknown Source)
	... 2 more

20/03/2009 11:25:14 org.exolab.castor.mapping.Mapping setBaseURL
INFO: mapping.xml is not a URL, trying to convert it to a file URL
20/03/2009 11:25:15 org.exolab.castor.mapping.Mapping loadMapping
INFO: Loading mapping descriptors from mapping.xml
org.exolab.castor.mapping.MappingException: Could not find the class MyOrder

loadMapping(java.lang.String url) 
Loads the mapping from the specified URL with type defaults to 'CastorXmlMapping'.