This is library supporting implementation of FSMs in Java application

All you have to do is to create enums for States and Events and define transitions. For examples check unit tests.

Basic usage

Include library as usual (binaries are available at jcenter repository):

compile 'pl.com.digita.simplefsm:simpleFsm:0.1'

Define enums containing states and events. There is no special requirements for those objects - you can use here virtually any enum.

enum States
{
    ON, OFF
}
    
enum Events
{
    SWITCH
}

Then declare and instantiate State Machine. Generic parameters are enum with States, enum with Events and StatefulContext.

StateMachine<States, Events, DefaultContext<States>> fsm;
        fsm = new StateMachine<>();

StateMachine holds all data in StatefulContext objects, so write your own or just use predefined one. Just take care about setting generic type - it must match first generic parameter of StateMachine. Here you set initial state. you can use single StateMachine to process different context.

DefaultContext<States> context = new DefaultContext<>();
context.setCurrentState(States.OFF);
fsm.setContext(context);

Last step is to define possible transitions (transitions have directions):

fsm
    .addTransition(ON, OFF, SWITCH)
    .addTransition(OFF, ON, SWITCH);
    

Then just pass some event to machine

fsm.onEvent(SWITCH);

Finally - read current status:

fsm.getContext().getCurrentState()

There is also possibility to add listeners and trigger some external processes as well as implement decision pseudo states - more examples will come soon.