Examples

Introduction

An example project download is provided that works both under Eclipse and via ant build.  This sets up the basic framework for GWT compilation and debugging in Hosted Mode, provides a basic Restlet-powered server, and demonstrates how the compiled GWT application can be bundled into an executable server JAR.

Download Restlet GWT -- Simple Example (application/x-zip-compressed, 2.5 MB, info)

This is a simple example demonstrating some basic patterns for using Restlet and GWT.  It produces an executable JAR file which depends only on core Restlet libraries (included in "lib") to start a small Java Web server on port 8888, which you can visit to access a  compiled GWT application that, in turn, talks to the Web server.

You can also run the application in GWT Hosted Mode under Eclipse by using the included SimpleExample.launch configuration; right click this and choose Run As ... SimpleExample.

It is structured as an Eclipse project; you should be able to import it into your Eclipse 3.3 or better workspace.  You can also run the ant build script directly to produce the executable.

You must supply your own GWT 1.5 binaries; update the Eclipse build path and/or the GWT_1.5 property in the ant build script to point to the GWT binaries for your platform.

Zip content

Name	Description
src	Source files of both: client page developped with GWT and Restlet, in package "org.restlet.example.gwt.client". Web server application developped with Restlet that serves the compiled web page and hosts a resource requested from the Web page.
build.xml	Ant script that: compiles the GWT page produces a final JAR file (RestletGWTSimpleExample.jar") of the server code in directory "dist". It also includes the "/etc/manifest.mf" file.
dist	Final directory where is located the final JAR of the server code.
etc	Directory where is located the "MANIFEST.MF" file of the server final JAR.
lib	Libraries taken from the Restlet framework (server and client APIs and implementations, GWT integration, servlet integration).
tomcat	Gathers configuration files for running the sample application inside Tomcat.
SimpleExample.launch	Used to run the application in GWT Hosted Mode under Eclipse; right click this and choose "Run As ... SimpleExample".
README.txt	Read it!

Description

GWT page

You can find the source code of this page in directory "src/org/restlet/example/gwt/client".

Once the server is running, this page can be accessed at the following URL: "http://localhost:8888/SimpleExample.html" .

This page is in charge to display several sample item such image, button, etc organized in panels. All of these objects are instances of GWT classes:

// Define an image
Image img = new Image("http://code.google.com/webtoolkit/logo-185x175.png");
// Define a button
final Button button = new Button("Click me");
[...]
// Define a panel
VerticalPanel vPanel = new VerticalPanel();
// We can add style names.
vPanel.addStyleName("widePanel");
vPanel.setHorizontalAlignment(VerticalPanel.ALIGN_CENTER);
// Add image, button, tree
vPanel.add(img);
vPanel.add(button);

These class illustrates also how to add an asynchronous call with AJAX inside the final Web page. It is as simple as to use a simple Restlet client in order to request the "ping" resource located at URL '"http://localhost:8888/ping" :

                final Client client = new Client(Protocol.HTTP);
                client.get("http://localhost:8888/ping", new Callback() {
                    @Override
                    public void onEvent(Request request, Response response) {
                        button.setText(response.getEntity().getText());
                    }
                });

Server side

Basically, the server s responsible to serve the generated page, and to respond to asynchronous call described just above.

The generated page is served by a simple Directory Restlet from the "bin" directory when the server is run under Eclipse.

The asynchronous call is delegated to the PingResource class which inherits from the Restlet Resource class. It simply answers to requests with a line of text.

    @Override
    public Representation represent(Variant variant) throws ResourceException {
    	return new StringRepresentation(
                "The Restlet server side is alive. Method called: "
                        + getRequest().getMethod(), MediaType.TEXT_PLAIN);
    }