Reading contacts from an XML file

The next improvement we'll make is to have the address book viewer application read an XML file to get contact information instead of a hard-coded list. There are a couple of nuances with this integration, so let's try that out now!

The list of contacts being displayed by the address book viewer is from hard-coded data in the ContactUtil class. Here's the sample structure of the XML file we'd like to read it from:

    <?xml version="1.0"?> 
    <addressbook> 
      <contact> 
        <firstname>Edsger</firstname> 
        <lastname>Dijkstra</lastname> 
        <address> 
          <street>5612</street> 
          <city>AZ</city> 
          <state>Eindhoven</state> 
          <country>Netherlands</country> 
       ...