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What is a state machine in Java?

What is a state machine in Java?

A state machine — also called a finite state machine or finite automaton — is a computational model used to build an abstract machine. These machines can only be in one state at a given time. Each state is a status of the system that changes to another state. These state changes are called transitions.

What is an example of a state machine?

There are many more examples of finite state machines we could use: a vending machine. a subway entrance turnstile. a heating system.

What is FSM in Java?

Wikipedia defines a finite-state machine (FSM)() as: an abstract machine that can be in exactly one of a finite number of states at any given time. An FSM is defined by a list of its states, its initial state, and the conditions for each transition.

How does a state machine work in Java?

ProcessEvent — where state transitions like the above are configured as a Java Enum class. 3. StateTransitionsManager — which responds to events. If the event is a pre-event then forwards the processing to a processor, or if the event is a post-event, then it changes the state to the final state. It also sets a default state if needed.

Which is an example of the state pattern in Java?

Usage examples: The State pattern is commonly used in Java to convert massive switch -base state machines into the objects. Here are some examples of the State pattern in core Java libraries: javax.faces.lifecycle.LifeCycle#execute () (controlled by the FacesServlet: behaviour is dependent on current phase (state) of JSF lifecycle)

How to implement a FSM Finite state machine in Java?

We think to implement three classes: State, Event and Machine . The state class presents a node in the FSM, we thought to implement it with State design pattern, every node will extend from the abstract class state and every class would handle different types of events and indicate transitions to a new state. Is it good idea in your opinion?

Which is an example of a state machine?

For instance, Wikipedia has an example for a turnstile that has the Locked and Unlocked states, which are affected by the events “coin” and “push”. The turnstile’s state transitions from Locked to Unlocked when the “coin” event happens.