@Configuration
public class StateMachineRegist {
private final String STATE_MACHINE_ID="stateMachineId";
/**
* 构建状态机实例
*/
@Bean
public StateMachine<ApplyStatusEnum, Event, LeaveContext> stateMachine() {
StateMachineBuilder<ApplyStatusEnum, Event, LeaveContext> stateMachineBuilder = StateMachineBuilderFactory.create();
//员工请假触发事件
//源状态和目标状态一致，我们可以用内部流转表示
stateMachineBuilder.internalTransition().within(ApplyStatusEnum.LEAVE_SUBMIT).on(Event.EMPLOYEE_SUBMIT).perform(doAction());
//部门主管审批触发事件（依赖上一个源状态：LEAVE_SUBMIT）
stateMachineBuilder.externalTransition().from(ApplyStatusEnum.LEAVE_SUBMIT).to(ApplyStatusEnum.LEADE_AUDIT_PASS).on(Event.DIRECTLEADER_AUDIT).when(checkIfPass()).perform(doAction());
stateMachineBuilder.externalTransition().from(ApplyStatusEnum.LEAVE_SUBMIT).to(ApplyStatusEnum.LEADE_AUDIT_REFUSE).on(Event.DIRECTLEADER_AUDIT).when(checkIfNotPass()).perform(doAction());
//hr事件触发(依赖上一个源状态:LEADE_AUDIT_PASS)
stateMachineBuilder.externalTransition().from(ApplyStatusEnum.LEADE_AUDIT_PASS).to(ApplyStatusEnum.HR_PASS).on(Event.HR_AUDIT).when(checkIfPass()).perform(doAction());
stateMachineBuilder.externalTransition().from(ApplyStatusEnum.LEADE_AUDIT_PASS).to(ApplyStatusEnum.HR_REFUSE).on(Event.HR_AUDIT).when(checkIfNotPass()).perform(doAction());
return stateMachineBuilder.build(STATE_MACHINE_ID);
}
}

ApplyStatusEnum state=stateMachine.fireEvent(ApplyStatusEnum.LEAVE_SUBMIT, Event.EMPLOYEE_SUBMIT,context);

@DisplayName("员工提交请假申请单")
@Test
public void employSubmitRequest(){
StateMachine<ApplyStatusEnum, Event, LeaveContext> stateMachine = StateMachineFactory.get("leaveStateMachineId");
LeaveContext context = new LeaveContext();
ApplyStatusEnum state=stateMachine.fireEvent(ApplyStatusEnum.LEAVE_SUBMIT, Event.EMPLOYEE_SUBMIT,context);
Assert.assertEquals(ApplyStatusEnum.LEAVE_SUBMIT.getCode(),state.getCode());
}
@DisplayName("部门主管审批通过")
@Test
public void leaderAuditPass(){
StateMachine<ApplyStatusEnum, Event, LeaveContext> stateMachine = StateMachineFactory.get("leaveStateMachineId");
LeaveContext context = new LeaveContext();
//主管审批通过
context.setIdea(0);
ApplyStatusEnum state=stateMachine.fireEvent(ApplyStatusEnum.LEAVE_SUBMIT, Event.DIRECTLEADER_AUDIT,context);
Assert.assertEquals(ApplyStatusEnum.LEADE_AUDIT_PASS.getCode(),state.getCode());
}
@DisplayName("部门主管审批不通过")
@Test
public void leaderAuditNotPass(){
StateMachine<ApplyStatusEnum, Event, LeaveContext> stateMachine = StateMachineFactory.get("leaveStateMachineId");
LeaveContext context = new LeaveContext();
//主管审批不通过
context.setIdea(1);
ApplyStatusEnum state=stateMachine.fireEvent(ApplyStatusEnum.LEAVE_SUBMIT, Event.DIRECTLEADER_AUDIT,context);
Assert.assertEquals(ApplyStatusEnum.LEADE_AUDIT_REFUSE.getCode(),state.getCode());
}
@DisplayName("HR审批通过")
@Test
public void hrAuditPass(){
StateMachine<ApplyStatusEnum, Event, LeaveContext> stateMachine = StateMachineFactory.get("leaveStateMachineId");
LeaveContext context = new LeaveContext();
//HR通过
context.setIdea(0);
ApplyStatusEnum state=stateMachine.fireEvent(ApplyStatusEnum.LEADE_AUDIT_PASS, Event.HR_AUDIT,context);
Assert.assertEquals(ApplyStatusEnum.HR_PASS.getCode(),state.getCode());
}
@DisplayName("HR审批不通过")
@Test
public void hrAuditNotPass(){
StateMachine<ApplyStatusEnum, Event, LeaveContext> stateMachine = StateMachineFactory.get("leaveStateMachineId");
LeaveContext context = new LeaveContext();
//HR审批不通过
context.setIdea(1);
ApplyStatusEnum state=stateMachine.fireEvent(ApplyStatusEnum.LEADE_AUDIT_PASS, Event.HR_AUDIT,context);
Assert.assertEquals(ApplyStatusEnum.HR_REFUSE.getCode(),state.getCode());
}

LEAVE_SUBMIT(1,"已申请"),
LEADE_AUDIT_PASS(2,"直属领导审批通过"),
LEADE_AUDIT_REFUSE(3,"直属领导审批失败"),
HR_PASS(4,"HR审批通过"),
HR_REFUSE(5,"HR审批拒绝");

//StateMachine
public class StateMachineImpl<S,E,C> implements StateMachine<S, E, C> {
private String machineId;
//一个状态机持有多个状态（from、to)
private final Map<S, State<S,E,C>> stateMap;
...
}
//State
public class StateImpl<S,E,C> implements State<S,E,C> {
protected final S stateId;
//同一个Event可以触发多个Transition
private Map<E, List<Transition<S, E,C>>> transitions = new HashMap<>();
...
}
//Transition
public class TransitionImpl<S,E,C> implements Transition<S,E,C> {
//源状态
private State<S, E, C> source;
//目标状态
private State<S, E, C> target;
//事件
private E event;
//条件
private Condition<C> condition;
//动作
private Action<S,E,C> action;
...
}

@Override
public S fireEvent(S sourceStateId, E event, C ctx) {
isReady();
//根据sourceStateId找到符合条件的Transition
Transition<S, E, C> transition = routeTransition(sourceStateId, event, ctx);
if (transition == null) {
Debugger.debug("There is no Transition for " + event);
failCallback.onFail(sourceStateId, event, ctx);
return sourceStateId;
}
//找到transition后执行transit方法(最终执行Action后返回目标State)
return transition.transit(ctx, false).getId();
}

/**
* 路由Transition
* @param sourceStateId 源状态ID
* @param event 事件
* @param ctx 上下文参数
* @return
*/
private Transition<S, E, C> routeTransition(S sourceStateId, E event, C ctx) {
//根据源状态ID查找源状态实例
State sourceState = getState(sourceStateId);
//查找源状态实例下的流转列表
List<Transition<S, E, C>> transitions = sourceState.getEventTransitions(event);
if (transitions == null || transitions.size() == 0) {
return null;
}
Transition<S, E, C> transit = null;
for (Transition<S, E, C> transition : transitions) {
if (transition.getCondition() == null) {
transit = transition;
} else if (transition.getCondition().isSatisfied(ctx)) {
//一旦匹配when函数内的触发条件,返回transition
transit = transition;
break;
}
}
return transit;
}

@Override
public State<S, E, C> transit(C ctx, boolean checkCondition) {
Debugger.debug("Do transition: "+this);
this.verify();
//checkCondition为false或不指定when触发条件亦或匹配when触发条件；都将执行自定义的perform函数
if (!checkCondition || condition == null || condition.isSatisfied(ctx)) {
//如果自定义的perform函数有指定，将执行perform函数
if(action != null){
action.execute(source.getId(), target.getId(), event, ctx);
}
return target;
}
Debugger.debug("Condition is not satisfied, stay at the "+source+" state ");
return source;
}