CDIListener.java

import org.jboss.weld.context.bound.BoundRequestContext;

import javax.enterprise.inject.spi.CDI;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletRequestEvent;
import javax.servlet.ServletRequestListener;
import javax.servlet.ServletResponse;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * Created by John.Ament on 2/22/14.
 */
public class CDIListener implements ServletRequestListener {
    @Override
    public void requestDestroyed(ServletRequestEvent servletRequestEvent) {
        BoundRequestContext requestContext = (BoundRequestContext)servletRequestEvent.getServletRequest().getAttribute("cdiRequestContext");
        Map<String,Object> requestMap = (Map<String,Object>)servletRequestEvent.getServletRequest().getAttribute("cdiRequestMap");
        requestContext.invalidate();
        requestContext.deactivate();
        requestContext.dissociate(requestMap);
    }

    @Override
    public void requestInitialized(ServletRequestEvent servletRequestEvent) {
        BoundRequestContext requestContext = CDI.current().select(BoundRequestContext.class).get();
        Map<String,Object> requestMap = new HashMap<>();
        requestContext.associate(requestMap);
        requestContext.activate();
        servletRequestEvent.getServletRequest().setAttribute("cdiRequestContext",requestContext);
        servletRequestEvent.getServletRequest().setAttribute("cdiRequestMap",requestMap);
    }
}

ResteasyBootstrap.java

        ResteasyDeployment deployment = new ResteasyDeployment();
        deployment.getActualResourceClasses().addAll(paths.getResources());
        deployment.getActualProviderClasses().addAll(paths.getProviders());
        deployment.setInjectorFactoryClass(CdiInjectorFactory.class.getName());

        ListenerInfo listener = listener(CDIListener.class);

        ServletInfo resteasyServlet = servlet("ResteasyServlet", HttpServlet30Dispatcher.class)
                .setAsyncSupported(true)
                .setLoadOnStartup(1)
                .addMapping(mapping);
        DeploymentInfo di = new DeploymentInfo()
                .addListener(listener)
                .setContextPath("/api")
                .addServletContextAttribute(ResteasyDeployment.class.getName(), deployment)
                .addServlet(resteasyServlet).setDeploymentName("ResteasyUndertow")
                .setClassLoader(JaxRsActivator.class.getClassLoader());

        DeploymentManager deploymentManager = Servlets.defaultContainer().addDeployment(di);
        deploymentManager.deploy();
        Undertow server = null;
        try {
            server = Undertow.builder()
                    .addHttpListener(8087, "0.0.0.0")
                    .setHandler(deploymentManager.start())
                    .build();
        } catch (ServletException e) {
            e.printStackTrace();
        }
        server.start();