Spring Rest Json Service inside a Felix OSGi container

Question

So im trying to create a remote Rest (JSON) service inside an OSGi bundle based in Felix with Maven.

my basic service interface :

@Controller
@RequestMapping("/s/fileService")
public interface RestFileService {

   @RequestMapping(value = "/file", method = RequestMethod.POST)
   @ResponseBody
   public String getFile(Long id);
}

My implementation of the interface

public class RestFileServiceImpl implements RestFileService{

    public String getFile(Long id) {
        return "test service";
    }
}

Normally i would add this to my web.xml

<servlet>
      <servlet-name>spring-mvc-dispatcher</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <init-param>
           <param-name>contextConfigLocation</param-name>
           <param-value>/WEB-INF/application-context.xml</param-value>
      </init-param>
      <load-on-startup>1</load-on-startup>
 </servlet>

 <servlet-mapping>
      <servlet-name>spring-mvc-dispatcher</servlet-name>
      <url-pattern>/rest/*</url-pattern>
 </servlet-mapping> 

And this would work fine inside a normal webapp. But now i want to put this inside an OSGi bundle.

Servlet 3.0 allows you to use @WebServlet to declare a servlet without the web.xml So i created a RestServlet

@WebServlet(value="/rest", name="rest-servlet")
public class RestServlet implements ServletContextListener {

private static Log sLog = LogFactory.getLog(RestServlet.class);

public void contextInitialized(ServletContextEvent arg0) {
    sLog.info("initializing the Rest Servlet");
}

public void contextDestroyed(ServletContextEvent arg0) {
    sLog.info("un-initializing the Rest Servlet");  
}
}

This is my OSGi activator:

public class Activator implements BundleActivator {

private static Log sLog = LogFactory.getLog(Activator.class);

public void start(BundleContext context) throws Exception {

    /*
     * Exposing the Servlet
     */

    Dictionary properties = new Hashtable();
    context.registerService(RestFileService.class.getName(), new  RestFileServiceImpl(), properties );

    sLog.info("Registered Remote Rest Service");
}

public void stop(BundleContext context) throws Exception {
    sLog.info("Unregistered Remote Rest Service");
}

}

I know Felix has its own http implementation with JAX but im trying to do this with spring annotations and as little XML as possible. Can i force it to register the annotation driven 3.0 servlet ?

What am i doing wrong ? is this even possible ?

Answer 1

If you're looking for an easy way to do REST in OSGi, take a look at some of the web components provided by the Amdatu project. This page pretty much explains how to create a REST service: https://amdatu.org/application/web/ and there is also a video which will talk you through the whole process: https://amdatu.org/generaltop/videolessons/