org.apache.commons.workflow.web
Class ActivityServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.apache.commons.workflow.web.ActivityServlet

All Implemented Interfaces:

Serializable, EventListener, javax.servlet.Servlet, javax.servlet.ServletConfig, ContextListener

public class ActivityServlet
extends javax.servlet.http.HttpServlet
implements ContextListener

Demonstration servlet that illustrates one way that workflow support can be integrated into web applications (or web services) without any dependency on application frameworks. For this implementation, a servlet definition (plus one or more servlet mappings) will be associated with each Activity supported by this web application.

Initialization parameters (defaults in square brackets):

• activity - Context-relative resource path to the definition file for the Activity that is supported by this servlet.
• attribute - Name of the session attribute under which our current Context implementation is stored. [org.apache.commons.workflow.web.CONTEXT]
• debug - The debugging detail level for this servlet, which controls how much information is logged. [0]
• detail - The debugging detail level for the Digester we utilize in initMapping(), which logs to System.out instead of the servlet log. [0]

Version:

$Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $

Author:

Craig R. McClanahan

See Also:

Serialized Form

Constructor Summary

ActivityServlet()

Method Summary

void	afterActivity(ContextEvent event) Invoked immediately after execution of the related Activity has been completed normally, been suspended, or been aborted by the throwing of a StepException.
void	afterStep(ContextEvent event) Invoked immediately after the specified Step was executed.
void	beforeActivity(ContextEvent event) Invoked immediately before execution of the related Activity has started.
void	beforeStep(ContextEvent event) Invoked immediately before the specified Step is executed.
void	destroy() Perform a graceful shutdown of this servlet instance.
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Process a GET transaction.
void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Process a POST transaction.
void	init() Perform a graceful startup of this servlet instance.
void	setActivity(Activity activity) Set the Activity associated with this instance.

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, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

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

Constructor Detail

ActivityServlet

public ActivityServlet()

Method Detail

destroy

public void destroy()

Perform a graceful shutdown of this servlet instance.

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class javax.servlet.GenericServlet

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
                  javax.servlet.http.HttpServletResponse response)
           throws IOException,
                  javax.servlet.ServletException

Process a GET transaction.

Overrides:

doGet in class javax.servlet.http.HttpServlet

Parameters:

request - The servlet request we are processing

response - The servlet response we are processing

Throws:

IOException - if an input/output exception occurs

javax.servlet.ServletException - if a servlet exception occurs

doPost

public void doPost(javax.servlet.http.HttpServletRequest request,
                   javax.servlet.http.HttpServletResponse response)
            throws IOException,
                   javax.servlet.ServletException

Process a POST transaction.

Overrides:

doPost in class javax.servlet.http.HttpServlet

Parameters:

request - The servlet request we are processing

response - The servlet response we are processing

Throws:

IOException - if an input/output exception occurs

javax.servlet.ServletException - if a servlet exception occurs

init

public void init()
          throws javax.servlet.ServletException

Perform a graceful startup of this servlet instance.

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException - if we cannot process the activity definition file for this activity

setActivity

public void setActivity(Activity activity)

Set the Activity associated with this instance.

Parameters:

activity - The new associated Activity

afterActivity

public void afterActivity(ContextEvent event)

Invoked immediately after execution of the related Activity has been completed normally, been suspended, or been aborted by the throwing of a StepException. The Step included in this event will be the last one to be executed.

Specified by:

afterActivity in interface ContextListener

Parameters:

event - The ContextEvent that has occurred

afterStep

public void afterStep(ContextEvent event)

Invoked immediately after the specified Step was executed.

Specified by:

afterStep in interface ContextListener

Parameters:

event - The ContextEvent that has occurred

beforeActivity

public void beforeActivity(ContextEvent event)

Invoked immediately before execution of the related Activity has started. The Step included in this event will be the first one to be executed.

Specified by:

beforeActivity in interface ContextListener

Parameters:

event - The ContextEvent that has occurred

beforeStep

public void beforeStep(ContextEvent event)

Invoked immediately before the specified Step is executed.

Specified by:

beforeStep in interface ContextListener

Parameters:

event - The ContextEvent that has occurred