com.beasys.commerce.foundation
Class StateMachine

java.lang.Object
  |
  +--com.beasys.commerce.foundation.StateMachine

public class StateMachine

extends java.lang.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 java.util.TreeSet	states
protected java.lang.String	TRANSITION_KEY_TOKEN
protected java.util.TreeMap	transitions

Constructor Summary

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

Method Summary

protected void	addTransition(Transition t)
java.lang.String	doTransition(java.lang.String transitionName) Given the name of the transition, perform the transition and return the new state.
WorkflowContext	getContext() Get the context of the Workflow.
java.lang.String	getCurrentStateName() Get the name of the current state
java.lang.String	getInitialStateName() Get the name of the initial state
java.lang.String[]	getOutgoingTransitions(java.lang.String state) Given the name of the state, return all transitions starting from that state
java.lang.String[]	getStateNames() Get all State names in an array of Strings.
java.lang.String[]	getTransitionNames() Get all transition names in an array of Strings.
java.lang.String	lookAheadTransition(java.lang.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

TRANSITION_KEY_TOKEN

protected java.lang.String TRANSITION_KEY_TOKEN

currentState

protected State currentState

initialState

protected State initialState

transitions

protected java.util.TreeMap transitions

states

protected java.util.TreeSet states

Constructor Detail

StateMachine

public StateMachine()

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

Method Detail

doTransition

public java.lang.String doTransition(java.lang.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

Parameters:

transition - the name of the transition to be performed

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 java.lang.String getCurrentStateName()

Get the name of the current state

Specified by:

getCurrentStateName in interface Workflow

Returns:

current state name

getInitialStateName

public java.lang.String getInitialStateName()

Get the name of the initial state

Specified by:

getInitialStateName in interface Workflow

Returns:

initial state name

getStateNames

public java.lang.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 java.lang.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 java.lang.String lookAheadTransition(java.lang.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

getOutgoingTransitions

public java.lang.String[] getOutgoingTransitions(java.lang.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

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

Parameters:

WorkflowContext - the new context for the underlying workflow engine.

addTransition

protected void addTransition(Transition t)