com.googlecode.jinahya.util.fsm

Class Machine

java.lang.Object

com.googlecode.jinahya.util.fsm.Machine

public abstract class Machine
extends java.lang.Object

A Finite State Machine.

Author:

Jin Kwon

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	PROPERTY_NAME_STATE Property name for 'state'.

Constructor Summary

Constructors

Constructor and Description
Machine(TaskContext taskContext) Creates a new instance.

Method Summary

Methods

Modifier and Type	Method and Description
void	addPropertyChangeListener(java.beans.PropertyChangeListener listener) Adds a property change listener for property changes.
void	addTransitionListener(TransitionListener listener) Adds given listener to this machine.
java.lang.Object	getProperty(java.lang.String name) Returns the property value mapped to given name.
State	getState() Returns current state.
protected abstract boolean	isAllowed(Transition transition) Checks if given transition is allowed.
boolean	isFinished() Returns finished flag value.
protected abstract boolean	isFinishing(Transition transition) Checks if given transition is an finishing condition.
boolean	isStarted() Returns started flag value.
protected abstract boolean	isStarting(Transition transition) Checks if given transition is a starting condition.
protected void	perform(TransitionContext context, Task... tasks) Performs each of given tasks with specified context.
void	removePropertyChangeListener(java.beans.PropertyChangeListener listener) Removes a property change listener for property changes.
void	removeTransitionListener(TransitionListener listener) Removes given listener from this machine.
java.lang.Object	setProperty(java.lang.String name, java.lang.Object value) Sets a property.
void	setState(State state) Sets state.

Methods inherited from class java.lang.Object

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

Field Detail

PROPERTY_NAME_STATE

public static final java.lang.String PROPERTY_NAME_STATE

Property name for 'state'.

See Also:

Constant Field Values

Constructor Detail

Machine

public Machine(TaskContext taskContext)

Creates a new instance.

Parameters:

taskContext - task context

Method Detail

getState

public final State getState()

Returns current state.

Returns:

state

setState

public final void setState(State state)
                    throws FSMException

Sets state.

Parameters:

state - new state

Throws:

FSMException - if an error occurs.

perform

protected void perform(TransitionContext context,
           Task... tasks)
                throws FSMException

Performs each of given tasks with specified context. Each task can be performed concurrently. This method must guarantee that all tasks are performed before return.

Parameters:

context - transition context

tasks - tasks

Throws:

FSMException - if an error occurs.

isStarted

public final boolean isStarted()

Returns started flag value.

Returns:

true if this machine has been started; false otherwise.

isFinished

public final boolean isFinished()

Returns finished flag value.

Returns:

true if this machine has been finished; false otherwise.

getProperty

public final java.lang.Object getProperty(java.lang.String name)

Returns the property value mapped to given name.

Parameters:

name - property name

Returns:

property value; may be null if the value itself is null or there is no value mapped to given name.

setProperty

public final java.lang.Object setProperty(java.lang.String name,
                           java.lang.Object value)

Sets a property.

Parameters:

name - property name

value - property value

Returns:

previously mapped value

isStarting

protected abstract boolean isStarting(Transition transition)

Checks if given transition is a starting condition. Default implementation always returns true. Override this method if customizations are needed.

Parameters:

transition - transition to check

Returns:

true if given transition is a starting condition; false otherwise.

isAllowed

protected abstract boolean isAllowed(Transition transition)

Checks if given transition is allowed. Default implementation always returns true. Override this method if customizations are needed.

Parameters:

transition - transition to check.

Returns:

true if given transition is allowed; false if not allowed.

isFinishing

protected abstract boolean isFinishing(Transition transition)

Checks if given transition is an finishing condition. Default implementation always returns false. Override this method if customizations are needed.

Parameters:

transition - transition to check

Returns:

true if given transition is a finishing condition; false otherwise.

addTransitionListener

public void addTransitionListener(TransitionListener listener)

Adds given listener to this machine.

Parameters:

listener - the listener to be added

removeTransitionListener

public void removeTransitionListener(TransitionListener listener)

Removes given listener from this machine.

Parameters:

listener - the listener to be removed

addPropertyChangeListener

public void addPropertyChangeListener(java.beans.PropertyChangeListener listener)

Adds a property change listener for property changes.

Parameters:

listener - the listener to be added

removePropertyChangeListener

public void removePropertyChangeListener(java.beans.PropertyChangeListener listener)

Removes a property change listener for property changes.

Parameters:

listener - the listener to be removed