Undertow is a new Servlet Container that is used by WildFly (JBoss Community Server). You can embed Undertow as you wish. Here's a a test that shows it in action.

import io.undertow.servlet.api.DeploymentInfo;
import org.jboss.resteasy.plugins.server.undertow.UndertowJaxrsServer;
import org.jboss.resteasy.test.TestPortProvider;
import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import javax.ws.rs.ApplicationPath;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.core.Application;
import java.util.HashSet;
import java.util.Set;

/**
 * @author <a href="mailto:bill@burkecentral.com">Bill Burke</a>
 * @version $Revision: 1 $
 */
public class UndertowTest
{
   private static UndertowJaxrsServer server;

   @Path("/test")
   public static class Resource
   {
      @GET
      @Produces("text/plain")
      public String get()
      {
         return "hello world";
      }
   }

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

   @BeforeClass
   public static void init() throws Exception
   {
      server = new UndertowJaxrsServer().start();
   }

   @AfterClass
   public static void stop() throws Exception
   {
      server.stop();
   }

   @Test
   public void testApplicationPath() throws Exception
   {
      server.deploy(MyApp.class);
      Client client = ClientBuilder.newClient();
      String val = client.target(TestPortProvider.generateURL("/base/test"))
                         .request().get(String.class);
      Assert.assertEquals("hello world", val);
      client.close();
   }

   @Test
   public void testApplicationContext() throws Exception
   {
      server.deploy(MyApp.class, "/root");
      Client client = ClientBuilder.newClient();
      String val = client.target(TestPortProvider.generateURL("/root/test"))
                         .request().get(String.class);
      Assert.assertEquals("hello world", val);
      client.close();
   }

   @Test
   public void testDeploymentInfo() throws Exception
   {
      DeploymentInfo di = server.undertowDeployment(MyApp.class);
      di.setContextPath("/di");
      di.setDeploymentName("DI");
      server.deploy(di);
      Client client = ClientBuilder.newClient();
      String val = client.target(TestPortProvider.generateURL("/di/base/test"))
                         .request().get(String.class);
      Assert.assertEquals("hello world", val);
      client.close();
   }
}

The Sun JDK comes with a simple HTTP server implementation (com.sun.net.httpserver.HttpServer) which you can run RESTEasy on top of.

 
      HttpServer httpServer = HttpServer.create(new InetSocketAddress(port), 10);
      contextBuilder = new HttpContextBuilder();
      contextBuilder.getDeployment().getActualResourceClasses().add(SimpleResource.class);
      HttpContext context = contextBuilder.bind(httpServer);
      context.getAttributes().put("some.config.info", "42");
      httpServer.start();

      contextBuilder.cleanup();
      httpServer.stop(0);
    

Create your HttpServer the way you want then use the org.jboss.resteasy.plugins.server.sun.http.HttpContextBuilder to initialize Resteasy and bind it to an HttpContext. The HttpContext attributes are available by injecting in a org.jboss.resteasy.spi.ResteasyConfiguration interface using @Context within your provider and resource classes.

Maven project you must include is:

 
  <dependency>
      <groupId>org.jboss.resteasy</groupId>
      <artifactId>resteasy-jdk-http</artifactId>
      <version>3.8.1.Final</version>
  </dependency>

RESTEasy integrates with the TJWS Embeddable Servlet container. It comes with this distribution, or you can reference the Maven artifact. You must also provide a servlet API dependency as well.

 
  <dependency>
      <groupId>org.jboss.resteasy</groupId>
      <artifactId>tjws</artifactId>
      <version>3.8.1.Final</version>
  </dependency>

  <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
  </dependency>

From the distribution, move the jars in resteasy-jaxrs.war/WEB-INF/lib into your classpath. You must both programmatically register your JAX-RS beans using the embedded server's Registry. Here's an example:

@Path("/")
public class MyResource {

   @GET
   public String get() { return "hello world"; }
 

   public static void main(String[] args) throws Exception 
   {
      TJWSEmbeddedJaxrsServer tjws = new TJWSEmbeddedJaxrsServer();
      tjws.setPort(8080);
      tjws.start();
      tjws.getRegistry().addPerRequestResource(RestEasy485Resource.class);
   }
}

The server can either host non-encrypted or SSL based resources, but not both. See the Javadoc for TJWSEmbeddedJaxrsServer as well as its superclass TJWSServletServer. The TJWS website is also a good place for information.

If you want to use Spring, see the SpringBeanProcessor. Here's a pseudo-code example

   public static void main(String[] args) throws Exception 
   {
      final TJWSEmbeddedJaxrsServer tjws = new TJWSEmbeddedJaxrsServer();
      tjws.setPort(8081);

      tjws.start();
      org.jboss.resteasy.plugins.server.servlet.SpringBeanProcessor processor = new SpringBeanProcessor(tjws.getDeployment().getRegistry(), tjws.getDeployment().getFactory();
      ConfigurableBeanFactory factory = new XmlBeanFactory(...);
      factory.addBeanPostProcessor(processor);
   }

NOTE: TJWS is now deprecated. Consider using the more modern Undertow.

RESTEasy has integration with the popular Netty project as well..

 
   public static void start(ResteasyDeployment deployment) throws Exception
   {
      netty = new NettyJaxrsServer();
      netty.setDeployment(deployment);
      netty.setPort(TestPortProvider.getPort());
      netty.setRootResourcePath("");
      netty.setSecurityDomain(null);
      netty.start();
   }
    

Maven project you must include is:

 
  <dependency>
      <groupId>org.jboss.resteasy</groupId>
      <artifactId>resteasy-netty</artifactId>
      <version>3.8.1.Final</version>
  </dependency>

RESTEasy has integration with the popular Vert.x project as well..

 
   public static void start(VertxResteasyDeployment deployment) throws Exception
   {
      VertxJaxrsServer server = new VertxJaxrsServer();
      server.setDeployment(deployment);
      server.setPort(TestPortProvider.getPort());
      server.setRootResourcePath("");
      server.setSecurityDomain(null);
      server.start();
   }
    

Maven project you must include is:

 
  <dependency>
      <groupId>org.jboss.resteasy</groupId>
      <artifactId>resteasy-vertx</artifactId>
      <version>3.8.1.Final</version>
  </dependency>
    

The server will bootstrap its own Vert.x instance and Http server.