Portlet application extended from web application

Request & Response

There are 4 phases of request and response :

Refer recipe of portlet request and response

Action Request

Render Request

Event Request – Portlet 2.0 intere-portlet-communication (IPC)

Resource Request – Portlet 2.0

Portlet Mode

There are 3 standard portlet mode

Handling

Handler we talking in here is controller created by you, For example : ViewBookController is a handler that implements the controller interface and included 2 methods.

• handlerActionRequest(request, response)
• handlerRenderRequest(request, response)

HandlerMappings

A Handler is any Object that can handler portlet request. Controller are an example of Handlers (default). If you like to use some other framework with DispatcherPortlet, a corresponding implementation of HandlerAdapter is needed. HandlerMappings are commonly based on URLS. But there is not URL within a portlet therefore we must use other mechanisms to controller the mappings. The 2 most common are portlet mode and a request parameter, but anything available to the portlet request can be used in a custom handler mapping.

PortletModeHandlerMapping

This is the simple handler mapping that maps incoming requests based on the current mode of portlet, view, edit, help

ParameterHandlerMapping

Used to navigate around multiple controllers without change the portlet mode, the simples way to do this is with a request parameter that is used as the key to control the mapping

ParameterHandlerMapping use specific request parameter to control the mapping, the default name of the parameter is ‘action’ but can changed using the ‘parameterName’ property.

PortletModeParameterHandlerMapping

As describe as the name, it combined the previous 2 handler mapping strategies to allow different navigation within each portlet mode.

More example

Mapping and Portlet Lifecycle

For an Action Request, the handler mapping will be consulted twice, once for action phase and agains for  render phase You can manipulate the criteria used for mapping during the action phase, eg: request parameter. This can result in the render phase getting  mapped to a different controller.

Annotation

Spring 3.0 supported portlet 2.0 annotation

Strategies in Controller

The showPage method has return String type, therefore we can assume it as render page, because it will look forward a jsp pages to render when this method is called.

Spring mvc portlet annotation use @RequestMapping strategies to map ‘EDIT’, ‘VIEW’ and ‘HELP’ mode. We can use portletModeParameterHandlerMapping create more interacting communication among the others controllers.

Example, ShowBooksController. By default annotated @Controller, @RequestMapping(“VIEW”). It will look for the method with annotated @RequestMapping method and return type String. The example below will return view page personJSPPages.jsp

Render Phase

Action Phase

Consider the method below annotated with @RequestMapping, and return type is void, therefore it will only process at onces, such like form submission. The method below will correspond to the action = ‘add’ in the portlet ‘VIEW’ mode.