RESTEasy WADL uses ResteasyWadlServlet to support servlet container. It can be registered into web.xml to enable WADL feature. Here is an example to show the usages of ResteasyWadlServlet in web.xml:

<servlet>
	<servlet-name>RESTEasy WADL</servlet-name>
	<servlet-class>org.jboss.resteasy.wadl.ResteasyWadlServlet</servlet-class>
</servlet>

<servlet-mapping>
	<servlet-name>RESTEasy WADL</servlet-name>
	<url-pattern>/application.xml</url-pattern>
</servlet-mapping>

The preceding configuration in web.xml shows how to enable ResteasyWadlServlet and mapped it to /application.xml. And then the WADL can be accessed from the configured URL:

/application.xml

This section introduces the recommended way to enable WADL support under Servlet Container situation. Firstly, you need to add a class then extends the ResteasyWadlDefaultResource to serve a resource path. Here is an example:

import org.jboss.resteasy.wadl.ResteasyWadlDefaultResource;
import javax.ws.rs.Path;

@Path("/")
public class MyWadlResource extends ResteasyWadlDefaultResource {
}

As the sample shown above, it will enable the ResteasyWadlDefaultResource and serves this URL by default:

/application.xml

To enable the GRAMMAR generation, you can extend the ResteasyWadlDefaultResource list this:

import org.jboss.resteasy.wadl.ResteasyWadlDefaultResource;
import org.jboss.resteasy.wadl.ResteasyWadlWriter;

import javax.ws.rs.Path;

@Path("/")
public class MyWadlResource extends ResteasyWadlDefaultResource {

    public MyWadlResource() {
        ResteasyWadlWriter.ResteasyWadlGrammar wadlGrammar = new ResteasyWadlWriter.ResteasyWadlGrammar();
        wadlGrammar.enableSchemaGeneration();
        getWadlWriter().setWadlGrammar(wadlGrammar);

    }
}

With the above setup, the WADL module will generate GRAMMAR automatically and register the service under this url:

/wadl-extended/xsd0.xsd

Above is the basic usage of WADL module under servlet container deployment.

RESTEasy has provided a ResteasyWadlDefaultResource to generate WADL info for its embedded containers. Here is and example to show how to use it with RESTEasy's Sun JDK HTTP Server container:

com.sun.net.httpserver.HttpServer httpServer =
	com.sun.net.httpserver.HttpServer.create(new InetSocketAddress(port), 10);

org.jboss.resteasy.plugins.server.sun.http.HttpContextBuilder contextBuilder = 
	new org.jboss.resteasy.plugins.server.sun.http.HttpContextBuilder();

contextBuilder.getDeployment().getActualResourceClasses()
	.add(ResteasyWadlDefaultResource.class);
contextBuilder.bind(httpServer);

ResteasyWadlDefaultResource.getServices()
	.put("/",
		ResteasyWadlGenerator
			.generateServiceRegistry(contextBuilder.getDeployment()));

httpServer.start();

From the above code example, we can see how ResteasyWadlDefaultResource is registered into deployment:

contextBuilder.getDeployment().getActualResourceClasses()
	.add(ResteasyWadlDefaultResource.class);

Another important thing is to use ResteasyWadlGenerator to generate the WADL info for the resources in deployment at last:

ResteasyWadlDefaultResource.getServices()
	.put("/",
		ResteasyWadlGenerator
			.generateServiceRegistry(contextBuilder.getDeployment()));

After the above configuration is set, then users can access "/application.xml" to fetch the WADL info, because ResteasyWadlDefaultResource has @PATH set to "/application.xml" as default:

@Path("/application.xml")
public class ResteasyWadlDefaultResource

RESTEasy WADL support for Netty Container is simliar to the support for JDK HTTP Server. It also uses ResteasyWadlDefaultResource to serve '/application.xml' and ResteasyWadlGenerator to generate WADL info for resources. Here is the sample code:

ResteasyDeployment deployment = new ResteasyDeploymentImpl();

netty = new NettyJaxrsServer();
netty.setDeployment(deployment);
netty.setPort(port);
netty.setRootResourcePath("");
netty.setSecurityDomain(null);
netty.start();

deployment.getRegistry()
	.addPerRequestResource(ResteasyWadlDefaultResource.class);        
ResteasyWadlDefaultResource.getServices()
	.put("/", ResteasyWadlGenerator.generateServiceRegistry(deployment));

Please note for all the embedded containers like JDK HTTP Server and Netty Container, if the resources in the deployment changes at runtime, the ResteasyWadlGenerator.generateServiceRegistry() need to be re-run to refresh the WADL info.

The RESTEasy Undertow Container is a embedded Servlet Container, and RESTEasy WADL provides a connector to it. To use RESTEasy Undertow Container together with WADL support, you need to add these three components into your maven dependencies:

<dependency>
	<groupId>org.jboss.resteasy</groupId>
	<artifactId>resteasy-wadl</artifactId>
	<version>${project.version}</version>
</dependency>
<dependency>
	<groupId>org.jboss.resteasy</groupId>
	<artifactId>resteasy-wadl-undertow-connector</artifactId>
	<version>${project.version}</version>
</dependency>
<dependency>
	<groupId>org.jboss.resteasy</groupId>
	<artifactId>resteasy-undertow</artifactId>
	<version>${project.version}</version>
</dependency>

The resteasy-wadl-undertow-connector provides a WadlUndertowConnector to help you to use WADL in RESTEasy Undertow Container. Here is the code example:

UndertowJaxrsServer server = new UndertowJaxrsServer().start();
WadlUndertowConnector connector = new WadlUndertowConnector();
connector.deployToServer(server, MyApp.class);

The MyApp class shown in above code is a standard Jakarta RESTful Web Services Application class in your project:

            
@ApplicationPath("/base")
public static class MyApp extends Application {
    @Override
    public Set<Class<?>> getClasses() {
        HashSet<Class<?>> classes = new HashSet<Class<?>>();
        classes.add(YourResource.class);
        return classes;
    }
}

After the Application is deployed to the UndertowJaxrsServer via WadlUndertowConnector, you can access the WADL info at "/application.xml" prefixed by the @ApplicationPath in your Application class. If you want to override the @ApplicationPath, you can use the other method in WadlUndertowConnector:

            
public UndertowJaxrsServer deployToServer(UndertowJaxrsServer server, Class<? extends Application> application, String contextPath)
            
        

The "deployToServer" method shown above accepts a "contextPath" parameter, which you can use to override the @ApplicationPath value in the Application class.