A State Machine implementation in Java

Simple State Machine with transitions, guards, composite state.

...but without sub-state machine, deferred signals, event queues...

Define the State Machine by subclassing State Machine and using the builders in the constructor. Se tests for usage.

    State onHold = state(ON_HOLD)
            .transition(HURL_PHONE).guardedBy(event -> PHONE_HURLED_AGAINST_WALL.equals(event.getName()))
            .to(phoneDestroyed)
            .transition(HANG_UP).guardedBy(event -> HUNG_UP.equals(event.getName()))
            .to(offHook)
            .transition(TAKE_OFF_HOLD).onTransition(stopMuzak).guardedBy(event -> TOOK_OFF_HOLD.equals(event.getName()))
            .to(connected)
            .build();

State Machine used in the unit tests

Phone State Machine Diagram

Inspired by simplestatemachine

Phone State Machine (Generated from code by Graphviz)

ATM State Machine Diagram

Inspired by ATM Bank

ATM State Machine (Generated from code by Graphviz)

The composite state ServingCustomer

A model containing the ATM state machine and the inner states of the composite state (not generated from code)