Creating virtual hosts using Restlet API consists of several lines of code (see Listing 1 below) and offers flexibility in configuring them. Note that both, setHostDomain and setHostPort methods, take Strings in java.util.regex patterns. Also, VirtualHost extends org.restlet.Router, and because of this you can "attach" to it Restlet's and Resource's

Listing 1

public class Naviquan extends Application {
  ...

  public static void main(String ...args) throws Exception {
    // Create a component with an HTTP server connector
    Component component = new Component();
    component.getServers().add(Protocol.HTTP, 80);
    component.getClients().add(Protocol.FILE);
    // Attach the application to the default host and start it
    component.getDefaultHost().attach("", new Naviquan(component.getContext()));
    
    // ==================================================
    // ============ Create virtual host =================
    // ==================================================
    VirtualHost host = new VirtualHost(component.getContext());
    host.setHostDomain("xyz.naviquan.com|localhost");
    host.setHostPort("80"); 
    host.attach("/xyz", XYZResource.class); 
    component.getHosts().add(host);
    


    ...
    component.start();
  }

  public Naviquan(Context context) {
    super(context);
    try {
       ...
    }
    catch (Exception ex) {
      ...
    }
  }
}

If the above looks a bit confusing here is another listing that, although illustrating same APIs, shows what may be called more consistent approach. In particular, in Listing 2, the main application class is called Camerata. Its main() method is used to start the whole thing. Note, that Camerata extends Restlet's Component class.

When virtual hosts are created, instances of Restlet's Application classes are created and "attached" to VirtualHost's. To clarify the approach, a skeleton coding is shown for Arredocenter, one of the two Application's created in the Camerata's constructor.

Obviously, to make this work, you'll have to fill in this skeleton code with your own that implements logic specific to your application. But this explicit implementation of the Component (Camerata class) and Application's (Naviquan and Arredocenter), and the way you glue together everything inside Camerata's constructor makes it easier to understand in my view the process of creating VirtualHost's in Web sites based and Restlet API.

Listing 2

public class Camerata extends Component {
 .....
 
 public static void main(String ...args) throws Exception {
  new Camerata(); }

 public Camerata() throws Exception {
  getServers().add(Protocol.HTTP, "[your IP]", 80);
  getClients().add(Protocol.FILE);
  ....

  /* arredocenter.com */
  VirtualHost host = new VirtualHost(getContext());
  host.setHostDomain("www.arredocenter.com|arredocenter.com");
  host.setHostPort("80");
  host.attach("", new Arredocenter(getContext()));
  getHosts().add(host);

  /* naviquan.com  */
  host = new VirtualHost(getContext());
  host.setHostDomain("www.naviquan.com|naviquan.com");
  host.setHostPort("80");
  host.attach("", new Naviquan(getContext()));
  getHosts().add(host);
  start();
 }
}

public class Arredocenter extends Application {
 public static Configuration freeMarkerConfig;
 ..... // everything else you need for your application

 public Arredocenter(Context context) {
  super(context);
  try {
   // build home where Home is your custom 'data' model/bean for home
   Home home = buildHome();
   ...
   // configure FreeMarker  FREEMARKER_TEMPLATE_LOCATION
   freeMarkerConfig = new Configuration();
   freeMarkerConfig.setDirectoryForTemplateLoading(new 
File(Constants.ARREDOCENTER_FREEMARKER_TEMPLATE_LOCATION));
   
freeMarkerConfig.setTemplateUpdateDelay(Constants.FREEMARKER_TEMPLATE_UPDATE_DEL
AY);
   
freeMarkerConfig.setTemplateExceptionHandler(TemplateExceptionHandler.HTML_DEBUG
_HANDLER);
   freeMarkerConfig.setObjectWrapper(ObjectWrapper.BEANS_WRAPPER);
   freeMarkerConfig.setDefaultEncoding("ISO-8859-1");
   freeMarkerConfig.setOutputEncoding("UTF-8");
   freeMarkerConfig.setLocale(Locale.US);
  }
  catch (Exception ex) {
   ex.printStackTrace();
  }
 }


 private Home buildHome() throws PoolException, NotesException {
  Home home = new Home();
  ....
 }

 /** createRoot */
 public Restlet createRoot() {
  Directory directory = new Directory(getContext(), 
Constants.ARREDOCENTER_STATIC_FILE_LOCATION);
  Router router = new Router(getContext());

  router.attach("/", 
HomeResource.class).getTemplate().setMatchingMode(org.restlet.util.Template.MODE
_EQUALS);
  router.attachDefault(directory);

  // router for reloading home
  router.attach("/home", HomeReloadedResource.class);
  ...
 }

 ..... // everything else you need for your application
}