Servlets not receiving injections

[meetoblivion]

So I created a simple servlet within my app that does a bit of proxying, to give nicer URLs for images that are requested. 

I noticed I was getting a NPE.  When I looked, I found the object I was injecting was resolving to null.

My servlet starts off like this..

public class ImageProxyServlet extends HttpServlet{
     @Current ImagePathBuilder imagePathBuilder;
     @Initializer
     public ImageProxyServlet() {
          super();
          // TODO Auto-generated constructor stub
     }

And the targetted bean:

@Named("imagePathBuilder")
public class ImagePathBuilder {

I've tried the bean w/ a few different scopes (RequestScope, SessionScope) and nothing resolves.

[gavin.king]

AFAIK, injection into servlets is not yet supported in the RI.

[meetoblivion]

That seems a little confusing, as the PREVIEW 1.0 docs have a servlet injection example.

Chapter 13

[gavin.king]

Well, I'm wrong then. Happens :-)

[meetoblivion]

Not saying you're wrong, I'm more inclined to believe the docs are wrong.  I added direct manager lookup via JNDI and it's there, so I'm inclined to think that someone was going to add in servlet injection, but the version of WebBeans on JBAS5.1 isn't working.  So docs are maybe out of sync w/ 5.1?

[viviansteller.vivian.steller.uni-ulm.de]

I think injection into servlets currently only works in Tomcat 6 (with the appropriate Listener configured in your context.xml file, see the docs for details).

Though, it's not implemented for any version of JBoss AS. See WBINT-5

[alin.heyoulin.qq.com]

you can see org.jboss.webbeans.environment.tomcat.WebBeansAnnotationProcessor

public void processAnnotations(Object instance) throws IllegalAccessException, InvocationTargetException, NamingException
   {
      manager.injectNonContextualInstance(instance);
   }



and org.jboss.webbeans.environment.servlet.Listener


if (tomcat)
      {
         // Try pushing a Tomcat AnnotationProcessor into the servlet context
         try
         {
            Class<?> clazz = Reflections.loadClass(WebBeansAnnotationProcessor.class.getName(), Object.class);
            Object annotationProcessor = clazz.getConstructor(WebBeansManager.class).newInstance(manager);
            sce.getServletContext().setAttribute(WebBeansAnnotationProcessor.class.getName(), annotationProcessor);
         }
         catch (Exception e) 
         {
            log.error("Unable to create Tomcat AnnotationProcessor. JSR-299 injection will not be available in Servlets, Filters etc.", e);
         }
      }


and org.jboss.webbeans.environment.tomcat.WebBeansLifecycleListener

 private AnnotationProcessor getProcessor()
            {
               if (processor == null)
               {
                  Object o = servletContext.getAttribute("org.jboss.webbeans.environment.tomcat.WebBeansAnnotationProcessor");
                  if (o instanceof AnnotationProcessor)
                  {
                     processor = (AnnotationProcessor) o;
                  }
                  else
                  {
                     return DUMMY_PROCESSOR;
                  }
               }
               return processor;
            }




so injection into servlets only works in tomacat,and you must add <Listener className="org.jboss.webbeans.environment.tomcat.WebBeansLifecycleListener"/> to context.xml

[pmuir]

Vivian Steller wrote on Jun 05, 2009 02:51:


I think injection into servlets currently only works in Tomcat 6 (with the appropriate Listener configured in your context.xml file, see the docs for details).

Though, it's not implemented for any version of JBoss AS. See WBINT-5

100% correct, JBoss 5 is still using some JBoss 4 legacy code in this area, and so we struggled to find a good way to make it work. There will probably have to be another JBoss release to have it work correctly :-(