org.springframework.webflow.execution.repository.support
Class SimpleFlowExecutionRepository

java.lang.Object
  org.springframework.webflow.execution.repository.support.AbstractFlowExecutionRepository
      org.springframework.webflow.execution.repository.support.AbstractConversationFlowExecutionRepository
          org.springframework.webflow.execution.repository.support.SimpleFlowExecutionRepository

All Implemented Interfaces:

FlowExecutionRepository

public class SimpleFlowExecutionRepository
extends AbstractConversationFlowExecutionRepository

Conversation manager based flow execution repository that stores exactly one flow execution per conversation.

It is important to note that by default use of this repository does not allow for duplicate submission in conjunction with browser navigational buttons (such as the back button). Specifically, if you attempt to "go back" and resubmit, the continuation id stored on the page in your browser history will not match the continuation id of the flow execution entry and access to the conversation will be disallowed. This is because the continuationId changes on each request to consistently prevent the possibility of duplicate submission (setAlwaysGenerateNewNextKey(boolean)).

This repository is specifically designed to be 'simple': incurring minimal resources and overhead, as only one FlowExecution is stored per conversation. This repository implementation should only be used when you do not have to support browser navigational button use, e.g. you lock down the browser and require that all navigational events to be routed explicitly through Spring Web Flow.

Author:

Erwin Vervaet, Keith Donald

Constructor Summary

SimpleFlowExecutionRepository(FlowExecutionStateRestorer executionStateRestorer, ConversationManager conversationManager)
Create a new simple repository using given state restorer and conversation manager.

Method Summary

protected java.io.Serializable	generateContinuationId(FlowExecution flowExecution) Template method used to generate a new continuation id for given flow execution.
UidGenerator	getContinuationIdGenerator() Returns the uid generation strategy used to generate continuation identifiers.
FlowExecution	getFlowExecution(FlowExecutionKey key) Return the FlowExecution indexed by the provided key.
FlowExecutionKey	getNextKey(FlowExecution flowExecution, FlowExecutionKey previousKey) Obtain the "next" flow execution key to be used as the flow execution's persistent identity.
boolean	isAlwaysGenerateNewNextKey() Returns whether or not a new flow execution key should always be generated before each put call.
protected java.io.Serializable	parseContinuationId(java.lang.String encodedId) Template method to parse the continuation id from the encoded string.
void	putFlowExecution(FlowExecutionKey key, FlowExecution flowExecution) Place the FlowExecution in this repository under the provided key.
void	setAlwaysGenerateNewNextKey(boolean alwaysGenerateNewNextKey) Sets a flag indicating if a new FlowExecutionKey should always be generated before each put call.
void	setContinuationIdGenerator(UidGenerator continuationIdGenerator) Sets the uid generation strategy used to generate unique continuation identifiers for flow execution keys.

Methods inherited from class org.springframework.webflow.execution.repository.support.AbstractConversationFlowExecutionRepository

createConversationParameters, generateKey, getContinuationId, getConversation, getConversationId, getConversationManager, getConversationScope, getLock, onBegin, onEnd, parseFlowExecutionKey, putConversationScope, removeFlowExecution

Methods inherited from class org.springframework.webflow.execution.repository.support.AbstractFlowExecutionRepository

getExecutionStateRestorer

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleFlowExecutionRepository

public SimpleFlowExecutionRepository(FlowExecutionStateRestorer executionStateRestorer,
                                     ConversationManager conversationManager)

Create a new simple repository using given state restorer and conversation manager.

Parameters:

executionStateRestorer - the flow execution state restoration strategy to use

conversationManager - the conversation manager to use

Method Detail

isAlwaysGenerateNewNextKey

public boolean isAlwaysGenerateNewNextKey()

Returns whether or not a new flow execution key should always be generated before each put call. Default is true.

setAlwaysGenerateNewNextKey

public void setAlwaysGenerateNewNextKey(boolean alwaysGenerateNewNextKey)

Sets a flag indicating if a new FlowExecutionKey should always be generated before each put call. By setting this to false a FlowExecution can remain identified by the same key throughout its life.

getContinuationIdGenerator

public UidGenerator getContinuationIdGenerator()

Returns the uid generation strategy used to generate continuation identifiers. Defaults to RandomGuidUidGenerator.

setContinuationIdGenerator

public void setContinuationIdGenerator(UidGenerator continuationIdGenerator)

Sets the uid generation strategy used to generate unique continuation identifiers for flow execution keys.

getNextKey

public FlowExecutionKey getNextKey(FlowExecution flowExecution,
                                   FlowExecutionKey previousKey)

Description copied from interface: FlowExecutionRepository

Obtain the "next" flow execution key to be used as the flow execution's persistent identity. This method should be called after a existing flow execution has resumed and remains active; thus needing to be updated. This repository may choose to return the previous key or generate a new key.

Specified by:

getNextKey in interface FlowExecutionRepository

Overrides:

getNextKey in class AbstractConversationFlowExecutionRepository

Parameters:

flowExecution - the flow execution

previousKey - the current key associated with the flow exection

getFlowExecution

public FlowExecution getFlowExecution(FlowExecutionKey key)

Description copied from interface: FlowExecutionRepository

Return the FlowExecution indexed by the provided key. The returned flow execution represents the restored state of an executing flow from a point in time. This should be called to resume a persistent flow execution.

Specified by:

getFlowExecution in interface FlowExecutionRepository

Specified by:

getFlowExecution in class AbstractConversationFlowExecutionRepository

Parameters:

key - the flow execution key

Returns:

the flow execution, fully hydrated and ready to signal an event against

putFlowExecution

public void putFlowExecution(FlowExecutionKey key,
                             FlowExecution flowExecution)

Description copied from interface: FlowExecutionRepository

Place the FlowExecution in this repository under the provided key. This should be called to save or update the persistent state of an active (but paused) flow execution.

Specified by:

putFlowExecution in interface FlowExecutionRepository

Specified by:

putFlowExecution in class AbstractConversationFlowExecutionRepository

Parameters:

key - the flow execution key

flowExecution - the flow execution

generateContinuationId

protected java.io.Serializable generateContinuationId(FlowExecution flowExecution)

Description copied from class: AbstractConversationFlowExecutionRepository

Template method used to generate a new continuation id for given flow execution. Subclasses must override.

Specified by:

generateContinuationId in class AbstractConversationFlowExecutionRepository

Parameters:

flowExecution - the flow execution

Returns:

the continuation id

parseContinuationId

protected java.io.Serializable parseContinuationId(java.lang.String encodedId)

Description copied from class: AbstractConversationFlowExecutionRepository

Template method to parse the continuation id from the encoded string.

Specified by:

parseContinuationId in class AbstractConversationFlowExecutionRepository

Parameters:

encodedId - the string identifier

Returns:

the parsed continuation id