com.ervacon.springframework.web.servlet.mvc.webflow
Class SimpleWebFlow

java.lang.Object
  com.ervacon.springframework.web.servlet.mvc.webflow.SimpleWebFlow

All Implemented Interfaces:

org.springframework.context.ApplicationContextAware, org.springframework.beans.factory.InitializingBean, WebFlow

public class SimpleWebFlow

extends java.lang.Object

implements WebFlow, org.springframework.beans.factory.InitializingBean, org.springframework.context.ApplicationContextAware

Simple web flow implementation. This class reads a web flow definition conforming to the web flow DTD from a specified resource. This implementation uses JDOM to access the XML flow definition. Several extension hook methods are provided in case a subclass wants to fine tune the behaviour of this class.

A web flow is configured in the Spring application context as a normal bean. Note that this flow implementation is thread safe: all state is initialized when the bean is created by the Spring application context. Once this is done, all state is read only. The modifiable state associated with a flow is stored in a seperate web flow memento that is associated with each active flow used by a client. The client (e.g. a controller implementation) is responsible for correct management of this memento.

Normally you should not use this class directly from within a web application. Instead, you use the provided WebFlowController to use and drive the flow.

Exposed configuration properties

name	default	description
webFlowResource	null	Specifies the resource from which the flow definition is loaded.

Author:

Erwin Vervaet

See Also:

WebFlowMemento, WebFlowController

Field Summary

protected org.apache.commons.logging.Log

log

Constructor Summary

SimpleWebFlow()

Method Summary

void	afterPropertiesSet()
org.springframework.web.servlet.ModelAndView	execute(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, java.lang.String state, java.lang.String event, WebFlowMementoStack mementos) Execute an event in a state of the web flow.
protected org.springframework.web.servlet.ModelAndView	executeActionState(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, org.jdom.Element stateDef, WebFlowMementoStack mementos) Execute given action state.
protected org.springframework.web.servlet.ModelAndView	executeEndState(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, org.jdom.Element stateDef, WebFlowMementoStack mementos) Execute given end state.
protected org.springframework.web.servlet.ModelAndView	executeFlowState(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, org.jdom.Element stateDef, WebFlowMementoStack mementos) Execute given flow state.
protected org.springframework.web.servlet.ModelAndView	executeState(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, org.jdom.Element stateDef, WebFlowMementoStack mementos) Execute given state.
protected org.springframework.web.servlet.ModelAndView	executeState(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, java.lang.String state, WebFlowMementoStack mementos) Execute specified state.
protected org.springframework.web.servlet.ModelAndView	executeViewState(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, org.jdom.Element stateDef, WebFlowMementoStack mementos) Execute given view state.
protected org.jdom.Element	findStateDef(java.lang.String state) Find the state definition for specified state.
protected org.jdom.Element	findTransitionDef(org.jdom.Element stateDef, java.lang.String event) Find the transition definition linked with specified event in given state definition.
org.springframework.context.ApplicationContext	getApplicationContext()
java.lang.String	getName() Return the name of this web flow.
org.springframework.core.io.Resource	getWebFlowResource() Get the resource from which the web flow is loaded.
void	load() Load the web flow definition from the resource specified by the "webFlowResource" property.
void	setApplicationContext(org.springframework.context.ApplicationContext applicationContext)
void	setWebFlowResource(org.springframework.core.io.Resource webFlowResource) Set the resource from which the web flow is loaded.
org.springframework.web.servlet.ModelAndView	start(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, WebFlowMementoStack mementos) Start the web flow.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

log

protected final org.apache.commons.logging.Log log

Constructor Detail

SimpleWebFlow

public SimpleWebFlow()

Method Detail

getWebFlowResource

public org.springframework.core.io.Resource getWebFlowResource()

Get the resource from which the web flow is loaded.

setWebFlowResource

public void setWebFlowResource(org.springframework.core.io.Resource webFlowResource)

Set the resource from which the web flow is loaded.

afterPropertiesSet

public void afterPropertiesSet()
                        throws java.lang.Exception

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

Throws:

java.lang.Exception

load

public void load()
          throws WebFlowException

Load the web flow definition from the resource specified by the "webFlowResource" property.

Throws:

WebFlowException

getApplicationContext

public org.springframework.context.ApplicationContext getApplicationContext()

setApplicationContext

public void setApplicationContext(org.springframework.context.ApplicationContext applicationContext)
                           throws org.springframework.beans.BeansException

Specified by:

setApplicationContext in interface org.springframework.context.ApplicationContextAware

Throws:

org.springframework.beans.BeansException

getName

public java.lang.String getName()

Return the name of this web flow. This is configured in the flow definition.

start

public org.springframework.web.servlet.ModelAndView start(javax.servlet.http.HttpServletRequest request,
                                                          javax.servlet.http.HttpServletResponse response,
                                                          WebFlowMementoStack mementos)
                                                   throws WebFlowException

Description copied from interface: WebFlow

Start the web flow.

Specified by:

start in interface WebFlow

Parameters:

request - current HTTP request

response - current HTTP response

mementos - flow call stack

Throws:

WebFlowException - in case of error

execute

public org.springframework.web.servlet.ModelAndView execute(javax.servlet.http.HttpServletRequest request,
                                                            javax.servlet.http.HttpServletResponse response,
                                                            java.lang.String state,
                                                            java.lang.String event,
                                                            WebFlowMementoStack mementos)
                                                     throws WebFlowException

Description copied from interface: WebFlow

Execute an event in a state of the web flow.

Specified by:

execute in interface WebFlow

Parameters:

request - current HTTP request

response - current HTTP response

state - state in which the event should be triggered

event - event that should be signaled

mementos - flow call stack

Throws:

WebFlowException - in case of error

findStateDef

protected org.jdom.Element findStateDef(java.lang.String state)

Find the state definition for specified state. Returns null if the state cannot be found.

findTransitionDef

protected org.jdom.Element findTransitionDef(org.jdom.Element stateDef,
                                             java.lang.String event)

Find the transition definition linked with specified event in given state definition. Returns null if there is no such transition.

executeState

protected org.springframework.web.servlet.ModelAndView executeState(javax.servlet.http.HttpServletRequest request,
                                                                    javax.servlet.http.HttpServletResponse response,
                                                                    java.lang.String state,
                                                                    WebFlowMementoStack mementos)
                                                             throws WebFlowException

Execute specified state.

Parameters:

request - current HTTP request

response - current HTTP response

state - the state to execute

mementos - flow call stack

Throws:

WebFlowException - in case of error

executeState

protected org.springframework.web.servlet.ModelAndView executeState(javax.servlet.http.HttpServletRequest request,
                                                                    javax.servlet.http.HttpServletResponse response,
                                                                    org.jdom.Element stateDef,
                                                                    WebFlowMementoStack mementos)
                                                             throws WebFlowException

Execute given state.

Parameters:

request - current HTTP request

response - current HTTP response

stateDef - definition of the state to execute

mementos - flow call stack

Throws:

WebFlowException - in case of error

executeViewState

protected org.springframework.web.servlet.ModelAndView executeViewState(javax.servlet.http.HttpServletRequest request,
                                                                        javax.servlet.http.HttpServletResponse response,
                                                                        org.jdom.Element stateDef,
                                                                        WebFlowMementoStack mementos)
                                                                 throws WebFlowException

Execute given view state. This will return the model and view to render.

Parameters:

request - current HTTP request

response - current HTTP response

stateDef - definition of the state to execute

mementos - flow call stack

Throws:

WebFlowException - in case of error

executeActionState

protected org.springframework.web.servlet.ModelAndView executeActionState(javax.servlet.http.HttpServletRequest request,
                                                                          javax.servlet.http.HttpServletResponse response,
                                                                          org.jdom.Element stateDef,
                                                                          WebFlowMementoStack mementos)
                                                                   throws WebFlowException

Execute given action state. This will execute all actions defined for the state untill a transition is triggered. Once that happens, a transition to the target state is done.

Parameters:

request - current HTTP request

response - current HTTP response

stateDef - definition of the state to execute

mementos - flow call stack

Throws:

WebFlowException - in case of error

executeFlowState

protected org.springframework.web.servlet.ModelAndView executeFlowState(javax.servlet.http.HttpServletRequest request,
                                                                        javax.servlet.http.HttpServletResponse response,
                                                                        org.jdom.Element stateDef,
                                                                        WebFlowMementoStack mementos)
                                                                 throws WebFlowException

Execute given flow state. This will load and execute a sub flow and do the necessary mapping to the sub flow model.

Parameters:

request - current HTTP request

response - current HTTP response

stateDef - definition of the state to execute

mementos - flow call stack

Throws:

WebFlowException - in case of error

executeEndState

protected org.springframework.web.servlet.ModelAndView executeEndState(javax.servlet.http.HttpServletRequest request,
                                                                       javax.servlet.http.HttpServletResponse response,
                                                                       org.jdom.Element stateDef,
                                                                       WebFlowMementoStack mementos)
                                                                throws WebFlowException

Execute given end state. This terminates the flow and does the necessary mapping to the parent flow if there is one.

Parameters:

request - current HTTP request

response - current HTTP response

stateDef - definition of the state to execute

mementos - flow call stack

Throws:

WebFlowException - in case of error

toString

public java.lang.String toString()