Design scheme for switching or cycling between states

Question

Is there a design template (for example, visitor, strategy, state, etc.) or some other design principle to help develop a good solution for modeling flow in states for an object, such as Task .

The task starts with the status New , then goes to the status of BeingHandled , then WaitingForApproval , and then it can be moved to Finish or NotApproved , which essentially refers to BeingHandled with additional information, saying that it has returned from WaitingForApproval .

So, in the general case, we have a common flow, and then there can be some internal flow inside it.

Thanks,

ashilon

Answer 1

This is not a template, but a concept: a finite state machine .

Thus, it is a finite state machine that can only have an active state at a time.

See what the Wikipedia article says in its first paragraph:

(FSM) ( : ), , , , . , . ; , , . , ; . FSM , .

Answer 2

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, , , currentState- . factory .

, ... , ... , - .

, , - http://www.javabrahman.com/design-patterns/state-design-pattern-in-java/

Answer 3

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- ( ), . , , New BeingHandled , , . , BeingHandled WaitingForApproval , , , - / . .

, , ( ). , ( , , ). FSM . FSM- Java Google.