squirrel使用參考

Squirrel使用 | 城的燈
https://segmentfault.com/a/1190000009906469
https://github.com/hekailiang/squirrel

內置事件

State Machine Lifecycle Events
|—StateMachineEvent /* Base event of all state machine event /
|—StartEvent / Fired when state machine started /
|—TerminateEvent / Fired when state machine terminated /
|—TransitionEvent / Base event of all transition event /
|—TransitionBeginEvent / Fired when transition began /
|—TransitionCompleteEvent / Fired when transition completed /
|—TransitionExceptionEvent / Fired when transition threw exception /
|—TransitionDeclinedEvent / Fired when transition declined /
|—TransitionEndEvent / Fired when transition end no matter declined or complete */

狀態(tài)機生命周期節(jié)點執(zhí)行順序

1. @onTransitionBegin
2. 這里首先判斷Condition.isSatisfied
3. 如果發(fā)生拒絕事件, 執(zhí)行@TransitionDeclinedEvent, 否則繼續(xù)往下執(zhí)行
4. @onBeforeActionExecuted
5. 這里執(zhí)行自定義的action(action有三種, exit/transit/entry), 先執(zhí)行exit即@State中的exitCallMethod
6. 如果action發(fā)生異常, 則執(zhí)行@OnActionExecException
7. @OnAfterActionExecuted
8. @OnBeforeActionExecuted
9. 這里執(zhí)行自定義的action(action有三種, exit/transit/entry), 這里執(zhí)行transit即@Trasit中的callMethod
10. @OnAfterActionExecuted
11. @OnBeforeActionExecuted
12. 這里執(zhí)行自定義的action(action有三種, exit/transit/entry), 這里執(zhí)行entry即@State中的entryCallMethod
13. @onAfterActionExecuted
14. 如果沒有發(fā)生異常,執(zhí)行@onTransitionComplete, 如果發(fā)生異常, 執(zhí)行@OnTransitionException
15. 最后執(zhí)行@OnTransitionEnd

Transit定義

常見正常操作

@Transitions({
        @Transit(from = "PROTECTING", to = "TERMINATION_CLAIM", on = "CLAIM_SETTLE", callMethod = "toTerminationClaim", when = Core2020PolicyStateCondition.class),
})
執(zhí)行順序如下:

1. 在狀態(tài)機start時,首先entryPROTECTING
2. 執(zhí)行condition
3. 執(zhí)行exitPROTECTING
4. 執(zhí)行callMethod = "toTerminationClaim"
5. 執(zhí)行condition
6. 執(zhí)行FromAnyToAny
7. 執(zhí)行entry TERMINATION_CLAIM
8. 最終狀態(tài)TERMINATION_CLAIM

結論: 可以看出不同@Transit之間的范圍是exit>transi, to狀態(tài)的entry,是狀態(tài)機內部最后做的

重復定義相同event

@Transitions({
        @Transit(from = "PROTECTING", to = "TERMINATION_INVALID_TIME", on = "CLAIM_SETTLE", callMethod = "toTerminationInvalidTime", when = Core2020PolicyStateCondition.class),
        @Transit(from = "PROTECTING", to = "TERMINATION_CLAIM", on = "CLAIM_SETTLE", callMethod = "toTerminationClaim", when = Core2020PolicyStateCondition.class),
})

from和to相等

@Transitions({
        @Transit(from = "PROTECTING", to = "PROTECTING", on = "CLAIM_SETTLE", callMethod = "toTerminationInvalidTime", when = Core2020PolicyStateCondition.class),
})
執(zhí)行順序如下:

1. 在狀態(tài)機start時,首先entryPROTECTING
2. 執(zhí)行condition
3. 執(zhí)行exitPROTECTING
4. 執(zhí)行entryPROTECTING
5. 執(zhí)行exitPROTECTING
6. 執(zhí)行callMethod = "toTerminationInvalidTime"
7. 執(zhí)行condition以及fromAnyToAny
8. 執(zhí)行entryPROTECTING
9. 最終狀態(tài)PROTECTING

注意: 多了一次entryPROTECTING和一次exitPROTECTING的結果讓人很迷惑, 最好不要這么用, 可以定義成internal的, 避免觸發(fā)entry/exit

其他

@Transitions({
    @Transit(from = "*", to = "*", on = "*", callMethod = "transitFromAnyToAnyWhenCore2020", when = Core2020PolicyStateCondition.class),
    @Transit(from = "SUSPEND", to = "PROTECTING", on = "PROTECT_RESTART", callMethod = "toProtectRestart", when = Core2020PolicyStateCondition.class),
    @Transit(from = "*", to = "*", on = "*", callMethod = "transitFromAnyToAnyWhenCore2020", when = Core2020PolicyStateCondition.class),
})
這樣: 第二個先執(zhí)行, 然后執(zhí)行第一個和第三個

約定優(yōu)于配置

如果存在約定名稱的方法, 
同時也存在配置的方法,  則先執(zhí)行配置的方法,  再執(zhí)行約定的方法,
例如:
@States({
        @State(name = "PROTECTING", exitCallMethod = "exitPROTECTING2"),
})
同時存在`exitPROTECTING`
則先執(zhí)行exitPROTECTING2,再執(zhí)行exitPROTECTING, 在他們前后分別執(zhí)行onBeforeActionExecuted和onAfterActionExecuted

* <Convention Over Configuration(約定優(yōu)于配置)的方式>
* exit[StateName] The method will be invoked when exit state 'A'. 
* So as the entry[StateName] ,beforeExitAny/afterExitAny and beforeEntryAny/afterEntryAny.
* Other Supported Naming Patterns:
* transitFrom[fromStateName]To[toStateName]On[eventName]When[conditionName]
* transitFrom[fromStateName]To[toStateName]On[eventName]
* transitFromAnyTo[toStateName]On[eventName]
* transitFrom[fromStateName]ToAnyOn[eventName]
* transitFrom[fromStateName]To[toStateName]
* on[eventName]
* </Convention Over Configuration(約定優(yōu)于配置)的方式>