Chapter 41. Embedded Containers

Undertow is a new Servlet Container that is used by WildFly (JBoss Community Server). It can be embedded if desired. Here's 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.jupiter.api.AfterAll;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;

import jakarta.ws.rs.ApplicationPath;
import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;
import jakarta.ws.rs.Produces;
import jakarta.ws.rs.client.Client;
import jakarta.ws.rs.client.ClientBuilder;
import jakarta.ws.rs.core.Application;
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()
      {
         return Set.of(Resource.class);
      }
   }

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

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

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

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

NOTE: This module is deprecated and should not be used.

> The Sun JDK comes with a simple HTTP server implementation (com.sun.net.httpserver.HttpServer) on which RESTEasy can be run 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 the HttpServer as desired, 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 an org.jboss.resteasy.spi.ResteasyConfiguration interface using @Context within the provider and resource classes.

Maven project you must include is:

 
  <dependency>
      <groupId>org.jboss.resteasy</groupId>
      <artifactId>resteasy-jdk-http</artifactId>
      <version>6.2.8.Final</version>
  </dependency>

RESTEasy has integration with the popular Netty project.

 
   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();
   }
    

Include this archive to use netty4

 
  <dependency>
      <groupId>org.jboss.resteasy</groupId>
      <artifactId>resteasy-netty4</artifactId>
      <version>6.2.8.Final</version>
  </dependency>

RESTEasy integrates with the reactor-netty project. This server adapter was created to pair with RESTEasy's reactor-netty based Jakarta RESTful Web Services client integration. Ultimately, if using reactor-netty for both the server and server-contained clients it will be possible to do things like share the same event loop for both server and client calls.

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

Include this archive to use the reactor netty feature

 
  <dependency>
      <groupId>org.jboss.resteasy</groupId>
      <artifactId>resteasy-reactor-netty</artifactId>
      <version>6.2.8.Final</version>
  </dependency>

RESTEasy has integration with the popular Vert.x project.

 
   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();
   }
    

Include this archive to use the Vertx feature

 
  <dependency>
      <groupId>org.jboss.resteasy</groupId>
      <artifactId>resteasy-vertx</artifactId>
      <version>6.2.8.Final</version>
  </dependency>
    

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

When a resource is called, it is done with the Vert.x Event Loop thread, keep in mind not block this thread and respect the Vert.x programming model, see the related Vert.x manual page.

Vert.x extends the RESTEasy registry to provide a new binding scope that creates resources per Event Loop:

 
  VertxResteasyDeployment deployment = new VertxResteasyDeployment();
  // Create an instance of resource per Event Loop
  deployment.getRegistry().addPerInstanceResource(Resource.class);
    

The per instance binding scope caches the same resource instance for each event loop providing the same concurrency model than a verticle deployed multiple times.

Vert.x can also embed a RESTEasy deployment, making it easy to use Jakarta RESTful Web Services annotated controller in Vert.x applications:

 
  Vertx vertx = Vertx.vertx();
  HttpServer server = vertx.createHttpServer();

  // Set an handler calling Resteasy
  server.requestHandler(new VertxRequestHandler(vertx, deployment));

  // Start the server
  server.listen(8080, "localhost");
    

Vert.x objects can be injected in annotated resources:

 
  @GET
  @Path("/somepath")
  @Produces("text/plain")
  public String context(
      @Context io.vertx.core.Context context,
      @Context io.vertx.core.Vertx vertx,
      @Context io.vertx.core.http.HttpServerRequest req,
      @Context io.vertx.core.http.HttpServerResponse resp) {
    return "the-response";
  }
    

EmbeddedJaxrsServer is an interface provided to enable each embedded container wrapper class to configure, start and stop its container in a standard fashion. Each server UndertowJaxrsServer, SunHttpJaxrsServer, NettyJaxrsServer, and VertxJaxrsServer implements EmbeddedJaxrsServer.

 
      public interface EmbeddedJaxrsServer<T> {
         T deploy();
         T start();
         void stop();
         ResteasyDeployment getDeployment();
         T setDeployment(ResteasyDeployment deployment);
         T setPort(int port);
         T setHostname(String hostname);
         T setRootResourcePath(String rootResourcePath);
         T setSecurityDomain(SecurityDomain sc);
      }