servlet - struts

Can anyone tell me how servet acts as a controller in struts?

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suresh

We define the name & path of the Action Servlet in the Web.xml.Web.xml is the deployment descriptor of the application. Thus,whenever any request has been made by submitting the JSP page control goes to the action servlet.Action Servlet intercepts & process the request by forwarding it to Model. Thus, in this way it acts as a controller.

In web.xml ur specifying the servlet name as

<servlet>
<servlet-name>action</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>

i.e wtever request comes from the brower , comes to web.xml and maps to org.apache.struts.action.ActionServlet(this is already implemented by apache).This ActionServlet will act as a controller . ActionServlet uses the initialization parameters /WEB-INF/struts-config.xml and send to particular Action

hi.. when request first comes it will handle by the controller(Action Servlet)...
In struts there is only one controller is called Action Servlet Controller...

Hi,
controller part is developed by servlet components. whenever client make a request,
front controller used to identify the request and give to the specific request processor which is used to handle request by doing the following..
protocal handling, form validation, action mapping,....etc
and give the request to the action and take the response give the response to the view.

front controller is one servlet component provided by framework.
request processor (application controller) is one servlet provided by framework.
action is one servlet developed by us.

thanks