com.beasys.commerce.foundation
Class StateMachine

java.lang.Object
  com.beasys.commerce.foundation.StateMachine

All Implemented Interfaces:

BusinessSmartComponent, Serializable, Workflow

Direct Known Subclasses:

PaymentWorkflow

public class StateMachine

extends Object

implements Workflow

This is the reference implemenation of a Workflow object. It provides a simple implemenation based on a set of states and transitions.

See Also:

Workflow, Serialized Form

Field Summary

protected State	currentState
protected State	initialState
protected TreeSet	states
protected String	TRANSITION_KEY_TOKEN
protected TreeMap	transitions

Constructor Summary

StateMachine()
Use WorkflowHome.create("com.beasys.commerce.foundation.StateMachine") to instantiate the workflow.

Method Summary

protected void	addTransition(Transition t)
String	doTransition(String transitionName) Given the name of the transition, perform the transition and return the new state.
WorkflowContext	getContext() Get the context of the Workflow.
String	getCurrentStateName() Get the name of the current state
String	getInitialStateName() Get the name of the initial state
String[]	getOutgoingTransitions(String state) Given the name of the state, return all transitions starting from that state
String[]	getStateNames() Get all State names in an array of Strings.
String[]	getTransitionNames() Get all transition names in an array of Strings.
String	lookAheadTransition(String transition) Given the name of the transition, look ahead the transition and return the predicted new state.
void	reset() Reset the current workflow state to the initial state
void	setContext(WorkflowContext workflowContext) Set the new context for the underlying workflow engine.

Methods inherited from class java.lang.Object

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

Field Detail

currentState

protected State currentState

initialState

protected State initialState

states

protected TreeSet states

TRANSITION_KEY_TOKEN

protected String TRANSITION_KEY_TOKEN

transitions

protected TreeMap transitions

Constructor Detail

StateMachine

public StateMachine()

Use WorkflowHome.create("com.beasys.commerce.foundation.StateMachine") to instantiate the workflow.

Method Detail

addTransition

protected void addTransition(Transition t)

doTransition

public String doTransition(String transitionName)
                    throws IllegalWorkflowTransitionException

Given the name of the transition, perform the transition and return the new state. If transition is invalid for the current state of the state machine, throw IllegalWorkflowTransitionException

Specified by:

doTransition in interface Workflow

Returns:

new state.

Throws:

IllegalWorkflowTransitionException - if the transition is invalid

getContext

public WorkflowContext getContext()

Get the context of the Workflow. This method should be used only by the classes that implement the Workflow interface.

Specified by:

getContext in interface Workflow

Returns:

WorkflowContext

getCurrentStateName

public String getCurrentStateName()

Get the name of the current state

Specified by:

getCurrentStateName in interface Workflow

Returns:

current state name

getInitialStateName

public String getInitialStateName()

Get the name of the initial state

Specified by:

getInitialStateName in interface Workflow

Returns:

initial state name

getOutgoingTransitions

public String[] getOutgoingTransitions(String state)
                                throws IllegalWorkflowTransitionException

Given the name of the state, return all transitions starting from that state

Specified by:

getOutgoingTransitions in interface Workflow

Parameters:

state - the name of the state

Returns:

a String[] of transition names.

Throws:

IllegalWorkflowTransitionException - if the transition is invalid

getStateNames

public String[] getStateNames()

Get all State names in an array of Strings.

Specified by:

getStateNames in interface Workflow

Returns:

String[] an array of Strings

getTransitionNames

public String[] getTransitionNames()

Get all transition names in an array of Strings.

Specified by:

getTransitionNames in interface Workflow

Returns:

String[] an array of Strings

lookAheadTransition

public String lookAheadTransition(String transition)
                           throws IllegalWorkflowTransitionException

Given the name of the transition, look ahead the transition and return the predicted new state. If transition is invalid for the current state of the state machine, throw IllegalWorkflowTransitionException.

Specified by:

lookAheadTransition in interface Workflow

Parameters:

transition - the name of the transition to be performed

Returns:

predicted new state.

Throws:

IllegalWorkflowTransitionException - if the transition is invalid

reset

public void reset()

Reset the current workflow state to the initial state

Specified by:

reset in interface Workflow

setContext

public void setContext(WorkflowContext workflowContext)

Set the new context for the underlying workflow engine. This method should be used only by the classes that implement the Workflow interface.

Specified by:

setContext in interface Workflow