net.sourceforge.anotherfsm

Class DeterministicStateMachine

java.lang.Object

net.sourceforge.anotherfsm.ProcessorAdapter

net.sourceforge.anotherfsm.DeterministicStateMachine

All Implemented Interfaces:

java.lang.AutoCloseable, Processor, StateMachine

Direct Known Subclasses:

SearchFsm, SearchStringFsm, SynchronizedStateMachine

public class DeterministicStateMachine
extends ProcessorAdapter
implements StateMachine

The deterministic state machine. This class is NOT thread safe.

Author:

Michal Turek

See Also:

SynchronizedStateMachine

Field Summary

Fields

Modifier and Type	Field and Description
private State	currentState The current state.
private java.util.List<Preprocessor>	preprocessors The preprocessors of events.
private java.util.List<StateListener>	stateListeners The listeners.
private java.util.Map<State,TransitionMap>	stateTransitions The transitions.
private java.util.List<TransitionListener>	transitionListeners The listeners.

Fields inherited from class net.sourceforge.anotherfsm.ProcessorAdapter

logger

Fields inherited from interface net.sourceforge.anotherfsm.StateMachine

INITIAL_STATE_NAME

Constructor Summary

Constructors

Constructor and Description
DeterministicStateMachine(java.lang.String name) Create the object.

Method Summary

Methods

Modifier and Type	Method and Description
void	addListener(StateListener listener) Add a new listener.
void	addListener(TransitionListener listener) Add a new listener.
void	addPreprocessor(Preprocessor preprocessor) Add a new preprocessor.
void	addState(State state) Add a new state.
private void	addStateInternal(State state) Add a new state to the state machine.
void	addTransition(Transition transition) Add a new transition.
void	close() Finish processing of the events and free all allocated resources.
boolean	easterEgg() Each software product should contain at least one easter egg.
State	getActiveState() Get the currently active state.
java.util.Set<State>	getActiveStates() Get the currently active states.
java.util.Set<State>	getStates() Get all defined states.
protected Transition	getTransition(State state, Event event) Get transition of a specified event type defined for a state.
java.util.Set<Transition>	getTransitions() Get all defined transitions.
boolean	isInFinalState() Is the active state a final state?
(package private) void	notifyEnter(State previous, Event event, State current) Process all state enter callbacks.
(package private) void	notifyExit(State current, Event event, State next) Process all state exit callbacks.
(package private) void	notifyTransition(Transition transition, State source, Event event, State destination) Process all transition callbacks.
private Event	preprocessEvent(Event event) Preprocess event using all registered preprocessors (recursive).
Event	process(Event event) Process the event.
private void	processCheck(Event event) Check the input event and the internal state before processing the event.
private Event	processInternal(Transition transition, Event eventToProcess, Event matchedEvent) Real processing of the event.
void	setStartState(State state) Set the start state.
void	start() Building of the processor is finished, prepare it to the events processing.
java.lang.String	toString()

Methods inherited from class net.sourceforge.anotherfsm.ProcessorAdapter

getName

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sourceforge.anotherfsm.Processor

getName

Field Detail

stateTransitions

private final java.util.Map<State,TransitionMap> stateTransitions

The transitions.

currentState

private State currentState

The current state.

stateListeners

private final java.util.List<StateListener> stateListeners

The listeners.

transitionListeners

private final java.util.List<TransitionListener> transitionListeners

The listeners.

preprocessors

private final java.util.List<Preprocessor> preprocessors

The preprocessors of events.

Constructor Detail

DeterministicStateMachine

public DeterministicStateMachine(java.lang.String name)

Create the object.

Parameters:

name - the name of the state machine

Method Detail

setStartState

public void setStartState(State state)
                   throws FsmException

Description copied from interface: StateMachine

Set the start state.

Specified by:

setStartState in interface StateMachine

Parameters:

state - the state

Throws:

FsmException

See Also:

StateMachine.start(), Processor.process(Event)

start

public void start()
           throws FsmException

Description copied from interface: Processor

Building of the processor is finished, prepare it to the events processing. It is expected this method is called just once.

Specified by:

start in interface Processor

Specified by:

start in interface StateMachine

Overrides:

start in class ProcessorAdapter

Throws:

FsmException - if something fails

See Also:

Processor.close()

close

public void close()

Description copied from interface: Processor

Finish processing of the events and free all allocated resources. This method can be called multiple times. Calling methods of the object after its Processor.close() should be avoided. The behavior is not defined and may cause unpredictable behavior, e.g. NullPointerException.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface Processor

Specified by:

close in interface StateMachine

Overrides:

close in class ProcessorAdapter

See Also:

Processor.start()

addState

public void addState(State state)
              throws FsmException

Description copied from interface: StateMachine

Add a new state.

Specified by:

addState in interface StateMachine

Parameters:

state - the state

Throws:

FsmException - if something fails

addStateInternal

private void addStateInternal(State state)

Add a new state to the state machine. If the state is already defined, no exception will be thrown.

Parameters:

state - the state

addTransition

public void addTransition(Transition transition)
                   throws FsmException

Description copied from interface: StateMachine

Add a new transition.

Specified by:

addTransition in interface StateMachine

Parameters:

transition - the transition

Throws:

FsmException - if something fails

addPreprocessor

public void addPreprocessor(Preprocessor preprocessor)

Description copied from interface: StateMachine

Add a new preprocessor. The preprocessors will be called in the registration order during preprocessing of the events. The state machine is responsible for starting and stopping of the registered preprocessors.

Specified by:

addPreprocessor in interface StateMachine

Parameters:

preprocessor - the preprocessor

See Also:

Processor.process(Event), StateMachine.start(), StateMachine.close()

addListener

public void addListener(StateListener listener)

Description copied from interface: StateMachine

Add a new listener.

Specified by:

addListener in interface StateMachine

Parameters:

listener - the listener

addListener

public void addListener(TransitionListener listener)

Description copied from interface: StateMachine

Add a new listener.

Specified by:

addListener in interface StateMachine

Parameters:

listener - the listener

notifyEnter

void notifyEnter(State previous,
               Event event,
               State current)
           throws FsmException

Process all state enter callbacks.

Parameters:

previous - the previous state

event - the event

current - the current state

Throws:

FsmException - if something fails

notifyExit

void notifyExit(State current,
              Event event,
              State next)
          throws FsmException

Process all state exit callbacks.

Parameters:

current - the current state

event - the event

next - the next state

Throws:

FsmException - if something fails

notifyTransition

void notifyTransition(Transition transition,
                    State source,
                    Event event,
                    State destination)
                throws FsmException

Process all transition callbacks.

Parameters:

transition - the transition

source - the source state

event - the event

destination - the destination state

Throws:

FsmException - if something fails

getActiveState

public State getActiveState()

Description copied from interface: StateMachine

Get the currently active state. Intended use is in deterministic state machines, for nondeterministic state machines only one of the active states is returned.

Specified by:

getActiveState in interface StateMachine

Returns:

the currently active state

See Also:

StateMachine.getActiveStates()

getActiveStates

public java.util.Set<State> getActiveStates()

Description copied from interface: StateMachine

Get the currently active states. Intended use is in nondeterministic state machines.

Specified by:

getActiveStates in interface StateMachine

Returns:

the currently active states

See Also:

StateMachine.getActiveState()

process

public Event process(Event event)
              throws FsmException

Description copied from interface: Processor

Process the event.

Specified by:

process in interface Processor

Parameters:

event - the input event

Returns:

the processed event

Throws:

FsmException - if something fails

preprocessEvent

private Event preprocessEvent(Event event)
                       throws FsmException

Preprocess event using all registered preprocessors (recursive). Helper method.

Parameters:

event - the event

Returns:

the original event, a newly generated event or null to ignore the event

Throws:

FsmException - if something fails

processCheck

private void processCheck(Event event)
                   throws FsmException

Check the input event and the internal state before processing the event.

Parameters:

event - the input event

Throws:

FsmException - if the event can't be processed for any reason

processInternal

private Event processInternal(Transition transition,
                    Event eventToProcess,
                    Event matchedEvent)
                       throws FsmException

Real processing of the event.

Parameters:

transition - the transition that should be processed

eventToProcess - the event that should be processed

matchedEvent - the event that matched, for logging purposes

Returns:

the final processed event

Throws:

FsmException - if something fails

getStates

public java.util.Set<State> getStates()

Description copied from interface: StateMachine

Get all defined states.

Specified by:

getStates in interface StateMachine

Returns:

the states

getTransitions

public java.util.Set<Transition> getTransitions()

Description copied from interface: StateMachine

Get all defined transitions.

Specified by:

getTransitions in interface StateMachine

Returns:

the transitions

getTransition

protected Transition getTransition(State state,
                       Event event)

Get transition of a specified event type defined for a state.

Parameters:

state - the state, it must be defined in the state machine

event - the event

Returns:

the transition or null if not defined

isInFinalState

public boolean isInFinalState()

Description copied from interface: StateMachine

Is the active state a final state?

Specified by:

isInFinalState in interface StateMachine

Returns:

true if at least one of the active states is final otherwise false

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

easterEgg

public boolean easterEgg()

Each software product should contain at least one easter egg.

Returns:

true