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Web features

Guice ServletModule support

By default, GuiceFilter is registered for both application and admin contexts. And so request and session scopes will be be available in both contexts. Also it makes injection of request and response objects available with provider (in any bean).

To register servlets and filters for main context use ServletModule, e.g.

public class WebModule extends ServletModule {

    protected void configureServlets() {

Request scoped beans

You can use request scoped beans in both main and admin contexts.

public class MyRequestScopedBean { ... }

To obtain bean reference use provider:

Provider<MyRequestScopedBean> myBeanProvider;

You can inject request and response objects in any bean:

Provider<HttpServletRequest> requestProvider
Provider<HttpServletResponse> responseProvider


By default, GuiceFilter is registered with REQUEST dispatcher type. If you need to use other types use option:

    .option(GuiceyOptions.GuiceFilterRegistration, EnumSet.of(REQUEST, FORWARD))


Note that async servlets and filters can't be used with guice servlet module (and so it is impossible to register GuiceFilter for ASYNC type). Use web installers for such cases.


GuiceFilter dispatch all requests for filters and servlets registered by ServletModule internally and there may be problems combining servlets from ServletModule and filters in main scope.

Disable ServletModule support

If you don't use servlet modules (for example, because web installers cover all needs) you can disable guice servlet modules support:


It will:

  • Avoid registration of GuiceFilter in both contexts
  • Remove request and session guice scopes support (because no ServletModule registered)
  • Prevent installation of any ServletModule (error will be thrown indicating duplicate binding)
  • HttpServletRequest and HttpServletResponse still may be injected in resources with Provider (but it will not be possible to use such injections in servlets, filters or any other place)

Disabling saves about ~50ms of startup time.

Web installers

Servlet api 3.0 provides @WebServlet, @WebFilter and @WebListener annotations, but they are not recognized in dropwizard (because dropwizard does not depend on jersey-annotations module). Web installers recognize this annotations and register guice-managed filters, servlets and listeners instances.

Web installers are disabled by default. To eable:


It will register WebInstallersBundle.

Web installers are not enabled by default, because dropwizard is primarily rest oriented framework and you may not use custom servlets and filters at all (so no need to spent time trying to recognize them). Moreover, using standard servlet api annotations may confuse users and so it must be user decision to enable such support. Other developers should be guided bu option name and its javadoc (again to avoid confusion, no matter that it will work exactly as expected)

Differences with GuiceServlet module

There is a difference between using web installers and registering servlets and filters with guice servlet module. Guice servlet module handles registered servlets and filters internally in GuiceFilter (which is installed by guicey in both app and admin contexts). As a side effect, there are some compatibility issues between guice servlets and native filters (rare and usually not blocking, but still). Web installers use guice only for filter or servlet instance creation and register this instance directly in dropwizard environment (using annotation metadata).

In many cases, annotations are more convenient way to declare servlet or filter registration comparing to servlet module.


Using annotations you can register async servlets and filters (with annotations asyncSupported=true option). In contrast, it is impossible to register async with guice servlet module.

Admin context

By default, web installers (servlet, filter, listener) target application context. If you want to install into admin context then use @AdminContext annotation.

For example:

public class MyServlet extneds HttpServlet { ... }

Will install servlet in admin context only.

If you want to install in both contexts use andMain attribute:

@AdminContext(andMain = true)
public class MyServlet extneds HttpServlet { ... }

In example above, servlet registered in both contexts.