import io.undertow.Undertow; import io.undertow.predicate.Predicates; import io.undertow.server.HandlerWrapper; import io.undertow.server.HttpHandler; import io.undertow.server.HttpServerExchange; import io.undertow.server.handlers.PathHandler; import io.undertow.server.handlers.PredicateHandler; import io.undertow.server.handlers.resource.ResourceHandler; import io.undertow.servlet.api.ConfidentialPortManager; import io.undertow.servlet.api.Deployment; import io.undertow.servlet.api.DeploymentInfo; import io.undertow.servlet.api.DeploymentManager; import io.undertow.servlet.api.FilterInfo; import io.undertow.servlet.api.ListenerInfo; import io.undertow.servlet.api.LoginConfig; import io.undertow.servlet.api.SecurityConstraint; import io.undertow.servlet.api.ServletContainer; import io.undertow.servlet.api.WebResourceCollection; import java.net.URL; import java.nio.file.Files; import java.nio.file.Paths; import java.util.EnumSet; import javax.inject.Inject; import javax.inject.Named; import javax.servlet.DispatcherType; import javax.servlet.ServletContext; import javax.servlet.ServletException; import org.apache.log4j.Logger; import org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter; import org.keycloak.adapters.AdapterConstants; import org.keycloak.adapters.undertow.KeycloakServletExtension; import com.billdrawer.website.common.Config; import com.billdrawer.website.listener.WebsiteServletContextListener; import com.google.inject.servlet.GuiceFilter; public class UndertowServer implements Server { private Logger _logger = Logger.getLogger(UndertowServer.class); private Undertow _server; private DeploymentManager _manager; private int _port; private String _host; @Inject public UndertowServer((a)Named(Config.STAGE) String stage, @Named(Config.SERVER_HOST) String host, @Named(Config.SERVER_PORT) int port, @Named(Config.SERVER_TIMEOUT) int timeout) { _port = port; _host = host; DeploymentInfo deploymentInfo = getDeploymentInfo(stage); ServletContainer _container = ServletContainer.Factory.newInstance(); _manager = _container.addDeployment(deploymentInfo); _manager.deploy(); Deployment deployment = _manager.getDeployment(); KeycloakServletExtension keycloak = new KeycloakServletExtension(); deploymentInfo.addServletExtension(keycloak); deploymentInfo.addInitParameter(AdapterConstants.AUTH_DATA_PARAM_NAME, getKeyloakJson()); keycloak.handleDeployment(deploymentInfo, _manager.getDeployment().getServletContext()); final ServletContext servletContext = deployment.getServletContext(); _logger.debug("Context initialized:"+servletContext.getContextPath()); } protected String getKeyloakJson() { String keycloak = ""; URL url = getClassLoader().getResource("keycloak.json"); if (url != null) { try { byte[] encoded = Files.readAllBytes(Paths.get(url.toURI())); keycloak = new String(encoded, "utf-8"); } catch (Exception e) { _logger.error("Can't read keycloak.json", e); } } return keycloak; } protected DeploymentInfo getDeploymentInfo(String stage) { final DeploymentInfo deploymentInfo = new DeploymentInfo(); deploymentInfo.setClassLoader(getClassLoader()); deploymentInfo.setContextPath("/"); deploymentInfo.setDefaultEncoding("UTF-8"); deploymentInfo.setDeploymentName("website.war"); deploymentInfo.setDisplayName("WebsiteServer"); deploymentInfo.setUrlEncoding("UTF-8"); deploymentInfo.addListener(new ListenerInfo(WebsiteServletContextListener.class)); FilterInfo guiceFilter = new FilterInfo("GuiceFilter", GuiceFilter.class); deploymentInfo.addFilter(guiceFilter); for (DispatcherType dispatcher : EnumSet.allOf(DispatcherType.class)) { deploymentInfo.addFilterUrlMapping(guiceFilter.getName(), "/*", dispatcher); } FilterInfo strutsPrepareAndExecuteFilter = new FilterInfo("StrutsFilter", StrutsPrepareAndExecuteFilter.class); deploymentInfo.addFilter(strutsPrepareAndExecuteFilter); for (DispatcherType dispatcher : EnumSet.allOf(DispatcherType.class)) { deploymentInfo.addFilterUrlMapping(strutsPrepareAndExecuteFilter.getName(), "/*", dispatcher); } deploymentInfo.addInitialHandlerChainWrapper(new HandlerWrapper() { @Override public HttpHandler wrap(final HttpHandler handler) { final ResourceHandler resourceHandler = new ResourceHandler(deploymentInfo.getResourceManager()); PredicateHandler predicateHandler = new PredicateHandler(Predicates.suffixes(".css",".html",".js"),resourceHandler, handler); return predicateHandler; } }); configureSecurity(deploymentInfo); return deploymentInfo; } protected void configureSecurity(DeploymentInfo deploymentInfo) { deploymentInfo.setLoginConfig(new LoginConfig("KEYCLOAK", "billdrawer")); deploymentInfo.setConfidentialPortManager(new ConfidentialPortManager() { @Override public int getConfidentialPort(HttpServerExchange exchange) { return _port; } }); SecurityConstraint securityConstraint = new SecurityConstraint(); WebResourceCollection webResourceCollection = new WebResourceCollection(); webResourceCollection.addUrlPattern("/dashboard/*"); securityConstraint.addWebResourceCollection(webResourceCollection); securityConstraint.addRoleAllowed("user"); deploymentInfo.addSecurityConstraint(securityConstraint); } protected ClassLoader getClassLoader() { return getClass().getClassLoader(); } public void start() { _logger.debug("starting..."); try { Undertow.Builder builder = Undertow.builder(); builder.addHttpListener(_port, _host); final PathHandler rootHandler = new PathHandler(); rootHandler.addPrefixPath(_manager.getDeployment().getDeploymentInfo().getContextPath(), _manager.start()); builder.setHandler(rootHandler); _server = builder.build(); _server.start(); } catch (ServletException e) { _logger.error("Unexpected exception", e); } _logger.info("###START###"); } public void stop() { _logger.debug("stopping..."); try { _manager.stop(); _server.stop(); } catch (ServletException e) { _logger.error("Unexpected exception", e); } _logger.info("###STOP###"); } } Everything is working until I do not try to load resources from context.