You should already have your backend REST resource available. On the client side (GWT) your need to

1. Add RestyGwt dependency to your project with maven

   <dependency>
       <groupId>org.fusesource.restygwt</groupId>
       <artifactId>restygwt</artifactId>
       <version>2.2.0</version>
   </dependency>
   

2. Add the inheritance to your module file

   <inherits name="org.fusesource.restygwt.RestyGWT"/>
   

3. Create your client interface

   public interface PizzaService extends RestService {
       @POST
       @Path("pizzaorders")
       public void order(PizzaOrder request, 
                         MethodCallback<OrderConfirmation> callback);
   }
   

4. Use your client where you want in you app

   PizzaService service = GWT.create(PizzaService.class);
   service.order(order, new MethodCallback<OrderConfirmation>() {
       
   public void onSuccess(Method method, OrderConfirmation response) {
     //code your stuff here
   }
   
   public void onFailure(Method method, Throwable exception) {
     //code your stuff here
   });
   

Default config is configured in import org.fusesource.restygwt.client.Defaults;

1. Service root. By default, RestyGWT will use module name to get rest service root, to change it, call on module load:

   Defaults.setServiceRoot("/rest/");
   

2. Date format. By default, RestyGWT will send unix timestamp as long for java.util.Date. If you don't want to do date processing on client side and just send a string, use

   Defaults.setDateFormat("yyyy-MM-dd'T'HH:mm");