| Spring Controller implementation that wraps a servlet instance which it manages
internally. Such a wrapped servlet is not known outside of this controller;
its entire lifecycle is covered here (in contrast to ServletForwardingController).
Useful to invoke an existing servlet via Spring's dispatching infrastructure,
for example to apply Spring HandlerInterceptors to its requests. This will work
even in a Servlet 2.2 container that does not support Servlet filters.
In particular, the main intent of this controller is to allow for applying
Spring's OpenSessionInViewInterceptor or OpenPersistenceManagerInViewInterceptor
to Struts actions in a Servlet 2.2 container. The Struts ActionServlet will be
wrapped by this controller in such a scenario, rather than defined in web.xml.
You then need to map "/*.do" (or whatever pattern you choose for your Struts actions)
onto this controller, which will in turn forward to the Struts ActionServlet.
Note that Struts has a special requirement in that it parses web.xml to
find its servlet mapping. Therefore, you need to specify the DispatcherServlet's
servlet name as "servletName" on this controller, so that Struts finds the
DispatcherServlet's mapping (thinking that it refers to the ActionServlet).
In a Servlet 2.3 container, when not using Spring's own web MVC framework,
it is recommended to use classic servlet mapping in combination with a filter,
for example Spring's OpenSessionInViewFilter or OpenPersistenceManagerInViewFilter.
Example: a DispatcherServlet XML context, forwarding "*.do" to the Struts
ActionServlet wrapped by a ServletWrappingController. All such requests will go
through the configured HandlerInterceptor chain (e.g. an OpenSessionInViewInterceptor).
From the Struts point of view, everything will work as usual.
<bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="interceptors">
<list>
<ref bean="openSessionInViewInterceptor"/>
</list>
</property>
<property name="mappings">
<props>
<prop key="*.do">strutsWrappingController</prop>
</props>
</property>
</bean>
<bean id="strutsWrappingController" class="org.springframework.web.servlet.mvc.ServletWrappingController">
<property name="servletClass">
<value>org.apache.struts.action.ActionServlet</value>
</property>
<property name="servletName">
<value>action</value>
</property>
<property name="initParameters">
<props>
<prop key="config">/WEB-INF/struts-config.xml</prop>
</props>
</property>
</bean>
Thanks to Keith Garry Boyce for pointing out the issue with Struts in a
Servlet 2.2 container, and for providing a prototype for accessing Struts
through Spring's web dispatching infrastructure!
author:
Juergen Hoeller
since:
1.1.1
See Also: ServletForwardingController
See Also: org.springframework.orm.hibernate.support.OpenSessionInViewInterceptor
See Also: org.springframework.orm.hibernate.support.OpenSessionInViewFilter
See Also: org.springframework.orm.jdo.support.OpenPersistenceManagerInViewInterceptor
See Also: org.springframework.orm.jdo.support.OpenPersistenceManagerInViewFilter | 