Architecture flexibility

Introduction

GWT's idiomatic RPC approach

Figure 1. (For comparison)  GWT's idiomatic RPC approach requires a Servlet container and communicates opaquely via JSON-encoded data atoms.  Alternatives involve writing low-level HTTP code.

The client-side Restlet-GWT module

Figure 2.  The client-side Restlet-GWT module (org.restlet.gwt) plugs into your Google Web Toolkit code as a module, and allows you to use the high level Restlet API to talk to any server platform.  XML and JSON representations are supported by default, and of course you can develop your own representational abstractions as well.  Code written for Restlet should be simple to port to Restlet-GWT.

Restlet-GWT can work alongside GWT-RPC

Figure 3. Restlet-GWT can work alongside GWT-RPC and other mechanisms.  REST APIs exposed by your custom Servlets can work alongside GWT-RPC in a Servlet container environment.

Restlet, an ideal server side companion for Restlet-GWT

Figure 4. .  Not only does Restlet provide a simple means of defining and mapping REST resources, it also provides useful facilities like the Redirector, which can be used to gateway requests to other servers, easily working around the single-source limitations of the AJAX programming model.  The Restlet server-side library even works in GWT Hosted Mode using the Noelios GWT Extension, so your entire application can be readily debugged.

Integration with standalone Restlet connectors

Figure 5.  If you don't need to use the Servlet-dependent GWT-RPC API, your compiled GWT application can be deployed very efficiently in a standalone Restlet environment using one of the embedded server connectors.  Restlet 1.1's Net server connector, for example, has no dependencies other than Java; with this, it is possible to create and release an extremely small, but very full featured, standalone application.