Package org.springframework.webflow.engine.builder

Class DefaultFlowHolder

java.lang.Object

org.springframework.webflow.engine.builder.DefaultFlowHolder

All Implemented Interfaces:

FlowDefinitionHolder

public class DefaultFlowHolder
extends Object
implements FlowDefinitionHolder

A flow definition holder that can detect changes on an underlying flow definition resource and refresh that resource automatically.

This class is thread-safe.

Note that this FlowDefinition holder uses a FlowAssembler. This class bridges the abstract world of flow definitions with the concrete world of flow implementations.

Author:

Keith Donald

See Also:

• FlowAssembler
• FlowDefinition

Constructor Summary

Constructors

Constructor	Description
DefaultFlowHolder(FlowAssembler assembler)	Creates a new refreshable flow definition holder that uses the configured assembler (GOF director) to drive flow assembly, on initial use and on any resource change or refresh.

Method Summary

Modifier and Type	Method	Description
void	destroy()	Indicates that the system is being shutdown and any resources flow resources should be released.
FlowDefinition	getFlowDefinition()	Returns the flow definition held by this holder.
String	getFlowDefinitionId()	Returns the id of the flow definition held by this holder.
String	getFlowDefinitionResourceString()	Returns a descriptive string that identifies the source of this FlowDefinition.
void	refresh()	Refresh the flow definition held by this holder.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

DefaultFlowHolder

public DefaultFlowHolder(FlowAssembler assembler)

Creates a new refreshable flow definition holder that uses the configured assembler (GOF director) to drive flow assembly, on initial use and on any resource change or refresh.

Parameters:

assembler - the flow assembler to use

Method Details

getFlowDefinitionId

public String getFlowDefinitionId()

Description copied from interface: FlowDefinitionHolder

Returns the id of the flow definition held by this holder. This is a lightweight method callers may call to obtain the id of the flow without triggering full flow definition assembly (which may be an expensive operation).

Specified by:

getFlowDefinitionId in interface FlowDefinitionHolder

getFlowDefinitionResourceString

public String getFlowDefinitionResourceString()

Description copied from interface: FlowDefinitionHolder

Returns a descriptive string that identifies the source of this FlowDefinition. This is also a lightweight method callers may call to obtain the logical resource where the flow definition resides without triggering flow definition assembly. Used for informational purposes.

Specified by:

getFlowDefinitionResourceString in interface FlowDefinitionHolder

Returns:

the flow definition resource string

getFlowDefinition

public FlowDefinition getFlowDefinition()
                                 throws FlowDefinitionConstructionException

Description copied from interface: FlowDefinitionHolder

Returns the flow definition held by this holder. Calling this method the first time may trigger flow assembly (which may be expensive).

Specified by:

getFlowDefinition in interface FlowDefinitionHolder

Throws:

FlowDefinitionConstructionException - if there is a problem constructing the target flow definition

refresh

public void refresh()
             throws FlowDefinitionConstructionException

Description copied from interface: FlowDefinitionHolder

Refresh the flow definition held by this holder. Calling this method typically triggers flow re-assembly, which may include a refresh from an externalized resource such as a file.

Specified by:

refresh in interface FlowDefinitionHolder

Throws:

FlowDefinitionConstructionException - if there is a problem constructing the target flow definition

destroy

public void destroy()

Description copied from interface: FlowDefinitionHolder

Indicates that the system is being shutdown and any resources flow resources should be released. After this method is called, calls to FlowDefinitionHolder.getFlowDefinition() are undefined. Should only be called once. May be a no-op if the held flow was never constructed to begin with.

Specified by:

destroy in interface FlowDefinitionHolder

toString

public String toString()

Overrides:

toString in class Object