problem on using injections within GuiceServletContextListener.contextInitialized

[ich du]

i try to sort up the deployment of my webapp. so i need to override contextInitilaized in GuiceServletContextListener. there i need to check the state of some module-bound objects. 

but i get problems:

i field-injected the needed objects (a logger and a external datasource) and tried to use them in contextInitialized but i get NullPointerExceptions all injected stuff is null in scope of contextInitialized (later, after deployment all injections work properly). the problem is that all guice injection starts within contextInitialized: "super.contextInitialized(servletContextEvent);"

so how to let guice inject the fields (or do i need another kind of injection?) after "super.contextInitialized(servletContextEvent);"?

thx in advance

[Tim Peierls]

Does your code look like this?

    public class Main extends GuiceServletContextListener {

@Override protected Injector getInjector() {

   return Guice.createInjector(stage, 

new MyServletModule(),           

// ... other modules ...

new AbstractModule() {

   @Override protected void configure() {

requestInjection(Main.this);

   }

}

   ));

}

@Override public void contextInitialized(ServletContextEvent event) {

   super.contextInitialized(event);

   // use someField here

}

@Inject volatile SomeType someField;

    }

This pattern works for me. If it doesn't work for you, I'd like to know why not.

--tim

[ich du]

in meantime i got it to work but it looks different:

public class AppGuiceContextListener extends GuiceServletContextListener {

    

    private Injector injector;

       private MetaDataService mds;

       private ServerLogger logger;

    @Override

    public final Injector getInjector() {

        injector = Guice.createInjector(new ServerModule(), new AdbServletModule());

        return injector;

    }

 

    @Override

    public final void contextInitialized(final ServletContextEvent servletContextEvent) {

        

        super.contextInitialized(servletContextEvent);

        mds = injector.getProvider(MetaDataService.class).get();

        logger = injector.getProvider(ServerLogger.class).get();

       ...

    }

  ...

}

[ich du]

(i forgot that i can't edit posts :-|)

i don't know if the above better but i remembered that examples with classic main method also use the injector directly to get objects. If i would have more objects needed at start-up your way seem more elegant Tim?! So i will keep it in mind - thx.