org.talika.tarsis.servlets
Class ControllerServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.talika.tarsis.servlets.AbstractServlet
              org.talika.tarsis.servlets.ControllerServlet

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public final class ControllerServlet

extends AbstractServlet

Implementation of controller servlet of Tarsis MVC Framework.

Version:

$Revision: 126 $

Author:

Jose M. Palomar

See Also:

Serialized Form

Constructor Summary

ControllerServlet()

Method Summary

void	destroy() Called by the servlet container to indicate to a servlet that the servlet is being taken out of service.
protected Command	findCommand(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Obtains command from client's request.
void	init(javax.servlet.ServletConfig config) Called by the servlet container to indicate to a servlet that the servlet is being placed into service.
protected void	process(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Processes requests for both HTTP GET and POST methods.
protected View	processCommand(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Command command) Process given command.
protected void	processView(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, View view) Process given view.

Methods inherited from class org.talika.tarsis.servlets.AbstractServlet

doGet, doPost, getContext, getLogger, getServletInfo

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ControllerServlet

public ControllerServlet()

Method Detail

init

public void init(javax.servlet.ServletConfig config)
          throws javax.servlet.ServletException

Called by the servlet container to indicate to a servlet that the servlet is being placed into service.

Initialization consits in calling super init method and storing in a local variable command factory instance for further use.

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class AbstractServlet

Parameters:

config - ServletConfig the ServletConfig object that contains configutation information for this servlet.

Throws:

javax.servlet.ServletException - if an exception occurs that interrupts the servlet's normal operation.

See Also:

Servlet.init(javax.servlet.ServletConfig)

destroy

public void destroy()

Called by the servlet container to indicate to a servlet that the servlet is being taken out of service.

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class AbstractServlet

See Also:

Servlet.destroy()

process

protected void process(javax.servlet.http.HttpServletRequest request,
                       javax.servlet.http.HttpServletResponse response)
                throws javax.servlet.ServletException,
                       java.io.IOException

Processes requests for both HTTP GET and POST methods.

Controller process requests this way:

1. Obtains command from request.
2. Process command action by calling execute method.
3. Process command view by forwarding or redirecting to it.

Specified by:

process in class AbstractServlet

Parameters:

request - servlet object that contains the request the client has made of the servlet.

response - servlet object that contains the response the servlet sends to the client.

Throws:

javax.servlet.ServletException - if the request could not be handled.

java.io.IOException - if an input or output error is detected when the servlet handles request.

findCommand

protected Command findCommand(javax.servlet.http.HttpServletRequest request,
                              javax.servlet.http.HttpServletResponse response)
                       throws SystemException

Obtains command from client's request.

Parameters:

request - HttpServletRequest client's request.

response - HttpServletResponse client's response.

Returns:

Command command obtained from client's request.

Throws:

SystemException - if no command is found.

processCommand

protected View processCommand(javax.servlet.http.HttpServletRequest request,
                              javax.servlet.http.HttpServletResponse response,
                              Command command)
                       throws ActionException,
                              SystemException

Process given command.

Parameters:

request - HttpServletRequest client's request.

response - HttpServletResponse client's reponse.

command - Command command to be processed.

Returns:

View view result of processing command.

Throws:

ActionException - if there is a problem executing action.

SystemException - if no view is found.

processView

protected void processView(javax.servlet.http.HttpServletRequest request,
                           javax.servlet.http.HttpServletResponse response,
                           View view)
                    throws SystemException,
                           javax.servlet.ServletException,
                           java.io.IOException

Process given view.

Parameters:

request - HttpServletRequest client's request.

response - HttpServletResponse client's reponse.

view - View view to be processed.

Throws:

SystemException - if view's type is unkown.

javax.servlet.ServletException - if the request could not be handled.

java.io.IOException - if an input or output error is detected when the servlet handles request.