import java.io.*;
import nu.xom.*;

public class ChangeDomains {
    public static void main(String[] arguments) throws IOException {
        try {
            // Create a tree from the XML document domains.xml
            Builder builder = new Builder();
            File xmlFile = new File("domains.xml");
            Document doc = builder.build(xmlFile);
            
            // Get the root element <domains>
            Element root = doc.getRootElement();
            
            // Loop through of its <domain> elements
            Elements rootChildren = root.getChildElements("domain");
            for (int i = 0; i < rootChildren.size(); i++) {
                
                // Get a <domain> element
                Element domain = rootChildren.get(i);
                
                // Get its <name> element and the text it encloses
                Element name = domain.getFirstChildElement("name");
                Text nameText = (Text) name.getChild(0);
                
                // Update any domain with the <name> text "java21days.com"
                if (nameText.getValue().equals("java21days.com"))
                    updateDomain(domain);
            }
            
            // Display the XML document
            System.out.println(doc.toXML());
        } catch (ParsingException pe) {
            System.out.println("Error: " + pe.getMessage());
            pe.printStackTrace();
            System.exit(-1);
        }
    }
    
    private static void updateDomain(Element domain) {
        // Get the domain's <dns> element
        Element dns = domain.getFirstChildElement("dns");
        
        // Get its <ttl> element
        Element ttl = dns.getFirstChildElement("ttl");
        
        // Replace its Text child with "604800"
        ttl.removeChild(0);
        ttl.appendChild("604800");
        
        // Create new elements and attributes to add
        Element email = new Element("email");
        Element address = new Element("address");
        Attribute user = new Attribute("user", "postmaster@java21days.com");
        Attribute destination = new Attribute("destination", "rcade");
        
        // Add them to the <domain> element
        domain.appendChild(email);
        email.appendChild(address);
        address.addAttribute(user);
        address.addAttribute(destination);
    }
}