Adding listener to servlet context in Spring

I am trying to use java config in spring 4 webmvc application. After surfing some examples in the Internet I have the following WebAppApplicationInitializer.

public class AppInit implements WebApplicationInitializer {
    private static final String CONFIG_LOCATION = "spring.examples.config";
    private static final String MAPPING_URL = "/rest/*";

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        WebApplicationContext context = getContext();
        servletContext.addListener(new ContextLoaderListener(context));
        ServletRegistration.Dynamic dispatcher = servletContext.addServlet("DispatcherServlet", new DispatcherServlet(context));
        dispatcher.setLoadOnStartup(1);
        dispatcher.addMapping(MAPPING_URL);
    }

    private AnnotationConfigWebApplicationContext getContext() {
        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
        context.setConfigLocation(CONFIG_LOCATION);
        return context;
    }

It works fine in jetty, tomcat, but when I am using resin 4.0.40. web server show the following error:

java.lang.IllegalStateException: Cannot initialize context because there is already a root application context present - check whether you have multiple ContextLoader* definitions in your web.xml! at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:277) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106) at com.caucho.server.webapp.WebApp.fireContextInitializedEvent(WebApp.java:3777) at com.caucho.server.webapp.WebApp.startImpl(WebApp.java:3687) at com.caucho.server.webapp.WebApp.access$400(WebApp.java:207) at com.caucho.server.webapp.WebApp$StartupTask.run(WebApp.java:5234) at com.caucho.env.thread2.ResinThread2.runTasks(ResinThread2.java:173) at com.caucho.env.thread2.ResinThread2.run(ResinThread2.java:118)

When I comment this line

servletContext.addListener(new ContextLoaderListener(context));

all works fine.

Question is what is the purpose of adding listener to servlet context? Is it wrong not to add listener to servlet context?

The problem was the bug http://bugs.caucho.com/view.php?id=5611 in resin 4.0.40. ServletContextListener#contextInitialized() called twice. In resin 4.0.41 all works fine