| Plain handler interface for components that process HTTP requests,
analogous to a Servlet. Only throws ServletException and IOException,
to allow for usage within any HttpServlet. Essentially the direct
equivalent of an HttpServlet, reduced to a handle method.
The easiest way to expose an HttpRequestHandler bean in Spring style
is to define it in Spring's root web application context and define
an HttpRequestHandlerServlet in web.xml, pointing at the
target HttpRequestHandler bean through its servlet-name which needs
to match the target bean name.
Supported as a handler type within Spring's DispatcherServlet,
being able to leverage the dispatcher's advanced mapping and interception
facilities. This is the recommended way of exposing an HttpRequestHandler,
while keeping the handler implementations free of direct dependencies
on a DispatcherServlet environment.
Typically implemented to generate binary responses directly,
with no separate view resource involved. This differentiates it from
a Controller within Spring's Web MVC framework. The lack of a ModelAndView
return value gives a clearer signature to callers other than the
DispatcherServlet, indicating there will never be a view to render.
As of Spring 2.0, Spring's HTTP-based remote exporters, such as
HttpInvokerServiceExporter and HessianServiceExporter, implement this
interface rather than the more extensive Controller interface,
for minimal dependencies on Spring-specific web infrastructure.
Note that RequestHandlers can optionally implement the LastModified
interface, just like Controllers can, provided that they run within
Spring's DispatcherServlet.
author:
Juergen Hoeller
since:
2.0
See Also: org.springframework.web.context.support.HttpRequestHandlerServlet
See Also: org.springframework.web.servlet.DispatcherServlet
See Also: org.springframework.web.servlet.ModelAndView
See Also: org.springframework.web.servlet.mvc.Controller
See Also: org.springframework.web.servlet.mvc.LastModified
See Also: org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter
See Also: org.springframework.remoting.httpinvoker.HttpInvokerServiceExporter
See Also: org.springframework.remoting.caucho.HessianServiceExporter
See Also: org.springframework.remoting.caucho.BurlapServiceExporter |