org.statefulj.fsm

Interface Persister<T>

All Known Implementing Classes:

MemoryPersisterImpl

public interface Persister<T>

A Persister is responsible for maintaining the persistence of the current State of the FSM

Author:

Andrew Hall

Method Summary

Methods

Modifier and Type	Method and Description
State<T>	getCurrent(T stateful) Returns the current state.
void	setCurrent(T stateful, State<T> current, State<T> next) Set the current state to the next state.

Method Detail

getCurrent

State<T> getCurrent(T stateful)

Returns the current state. This will not call into the underlying database

Parameters:

stateful - Stateful Entity

Returns:

current State of the Stateful Entity

setCurrent

void setCurrent(T stateful,
              State<T> current,
              State<T> next)
                throws StaleStateException

Set the current state to the next state. Will serialize access to the persistence and ensure that expected current state is indeed the current state. If not, will throw a StaleStateException

Parameters:

stateful - StatefulEntity

current - Expected current State of the Stateful Entity

next - The value of the updated State

Throws:

StaleStateException - thrown if the state value of the Stateful Entity is not equal to the passed in current value