org.springframework.web.portlet.mvc
Interface Controller

All Known Implementing Classes:

AbstractCommandController, AbstractController, AbstractFormController, AbstractWizardFormController, BaseCommandController, ParameterizableViewController, PortletModeNameViewController, PortletWrappingController, SimpleFormController

public interface Controller

Base portlet Controller interface, representing a component that receives RenderRequest/RenderResponse and ActionRequest/ActionResponse like a Portlet but is able to participate in an MVC workflow.

Any implementation of the portlet Controller interface should be a reusable, threadsafe class, capable of handling multiple portlet requests throughout the lifecycle of an application. To be able to configure Controller(s) in an easy way, Controllers are usually JavaBeans.

Workflow:

After the DispatcherPortlet has received a request and has done its work to resolve locales, themes and suchlike, it tries to resolve a Controller to handle that request, using a HandlerMapping. When a Controller has been found, the handleRenderRequest or handleActionRequest method will be invoked, which is responsible for handling the actual request and - if applicable - returning an appropriate ModelAndView. So actually, these method are the main entrypoint for the DispatcherPortlet which delegates requests to controllers. These method - and also this interface - should preferrably not be implemented by custom controllers directly, since abstract controllers also provided by this package already provide a lot of functionality for typical use cases in portlet applications. A few examples of those controllers: AbstractController, AbstractCommandController, AbstractFormController, SimpleFormController.

So basically any direct implementation of the Controller interface just handles RenderRequests/ActionRequests and should return a ModelAndView, to be further used by the DispatcherPortlet. Any additional functionality such as optional validation, form handling, etc should be obtained through extending one of the abstract controller classes mentioned above.

Since:

2.0

Author:

William G. Thompson, Jr., John A. Lewis

See Also:

SimpleControllerHandlerAdapter, AbstractController, AbstractCommandController, AbstractFormController, SimpleFormController, ApplicationContextAware, ResourceLoaderAware, PortletContextAware

Method Summary

void	handleActionRequest(ActionRequest request, ActionResponse response) Process the action request.
ModelAndView	handleRenderRequest(RenderRequest request, RenderResponse response) Process the render request and return a ModelAndView object which the DispatcherPortlet will render.

Method Detail

handleActionRequest

void handleActionRequest(ActionRequest request,
                         ActionResponse response)
                         throws Exception

Process the action request. There is nothing to return.

Parameters:

request - current portlet action request

response - current portlet action response

Throws:

Exception - in case of errors

handleRenderRequest

ModelAndView handleRenderRequest(RenderRequest request,
                                 RenderResponse response)
                                 throws Exception

Process the render request and return a ModelAndView object which the DispatcherPortlet will render. A null return value is not an error: It indicates that this object completed request processing itself, thus there is no ModelAndView to render.

Parameters:

request - current portlet render request

response - current portlet render response

Returns:

a ModelAndView to render, or null if handled directly

Throws:

Exception - in case of errors