Cola-StateMachine状态机的实战使用

builder.externalTransition()
  .from(States.STATE1)
  .to(States.STATE2)
  .on(Events.EVENT1)
  .when(checkCondition())
  .perform(doAction());

  <dependency>
    <groupId>com.alibaba.cola</groupId>
    <artifactId>cola-component-statemachine</artifactId>
    <version>4.2.1</version>
  </dependency>

  //订单状态
  public enum OrderStatusEnum {
    INIT("初始化", 0),
    PAY_ONLINE("待支付", 1),
    WAITING_FOR_RECEIVED("待接单", 2),
    WAITING_DELIVERY("待发货", 3),
    PART_DELIVERY("部分发货", 4),
    DELIVER_ALL("待收货", 5),
    RECEIVED("已收货", 6),
    DONE("已完成", 7),
    CANCEL("已关闭", 8);
  }

  //订单事件
  public enum OrderEventEnum {
    CREATE_ORDER(1, "创建订单"),
    REPAY(2, "支付"),
    CANCEL_ORDER(3, "取消订单"),
    TAKE_ORDER(4, "接单"),
    REJECT_ORDER(5, "拒单"), 
    DELIVERY_PART(6, "部分发货"),
    DELIVERY_ALL(7, "全部发货"),
    CONFIRM_RECEIPT(8, "确认收货"),
    EXTEND_RECEIPT(9, "延长收货"),
    COMPLETE(10, "交易完成");
  }

  //订单状态机ID 枚举
  public enum OrderStateMachineIdEnum {
    ORDER_OF_SALE("ORDER_OF_SALE",
    OrderBizEnum.SALE_ORDER, "订单状态机");
  }

  public class OrderOfSaleStateMachine implements OrderStateMachine {
    public void initialize() {

       //对状态机开始构建，并在StateMachineFactory中注册
       StateMachineBuilder<OrderStatusEnum, OrderEventEnum, OrderContext> builder
       = StateMachineBuilderFactory.create();

       /**
       * 创建订单: 初始化 -> 待支付
       * externalTransition : 用于一个流转的构建器
       */
       builder.externalTransition().from(OrderStatusEnum.INIT).to(OrderStatusEnum.PAY_ONLINE)
       .on(OrderEventEnum.CREATE_ORDER).when(checkOrder()).perform(createOrderAction);

       /**
       * 部分发货: 部分发货
       * internalTransition : 内部流转
       */
       builder.internalTransition()
       .within(OrderStatusEnum.PART_DELIVERY)
       .on(OrderEventEnum.DELIVERY_PART)
       .when(checkOrder())
       .perform(deliverOrderAction);

       /**
       * 取消订单: 待支付、待发货、待收货 -> 待支付
       * externalTransitions : 用于多个流转的构建器
       */
       builder.externalTransitions()
       .fromAmong(OrderStatusEnum.PAY_ONLINE,OrderStatusEnum.WAITING_FOR_RECEIVED,                                      OrderStatusEnum.WAITING_DELIVERY)
       .to(OrderStatusEnum.CANCEL)
       .on(OrderEventEnum.CANCEL_ORDER)
       .when(checkOrder())
       .perform(cancelOrderAction);


       // 说明：cola statemachine 构建后，会自动 StateMachineFactory 注册。
       // 构建成功后根据 StateMachineFactory.get(machineId) 获取状态机，不允许重复构建，重复构建会报错。
       builder.build(this.getStateMachineIdEnum().getMachineId());
    }

    @Override
    public OrderStateMachineIdEnum getStateMachineIdEnum() {
        return OrderStateMachineIdEnum.ORDER_OF_SALE;
    }

  /*
   * 设置一个外部状态转义类型的builder,并设置from\to\on\when\perform
   */
  builder.externalTransition()
    .from(OrderStatusEnum.INIT)
    .to(OrderStatusEnum.PAY_ONLINE)
    .on(OrderEventEnum.CREATE_ORDER)
    .when(checkOrder())
    .perform(createOrderAction);

  public class CreateOrderAction implements Action<OrderStatusEnum, OrderEventEnum, OrderContext> {
    @Override
    public void execute(OrderStatusEnum from, OrderStatusEnum to, OrderEventEnum event, OrderContext context) {
      // ...
      // 1.获取状态机
      StateMachine<OrderStatusEnum, OrderEventEnum, OrderContext> stateMachine = getStateMachine();
      // 2.组状态机 messageContext
      OrderContext orderContext = buildContext();
      // 3.状态机事件触发
      stateMachine.fireEvent(OrderStatusEnum.INIT, OrderEventEnum.CREATE_ORDER, orderContext);
      // ...
    }
  }

  /**
   * 部分发货: 部分发货
   * internalTransition : 内部流转
   */
  builder.internalTransition()
    .within(OrderStatusEnum.PART_DELIVERY)
    .on(OrderEventEnum.DELIVERY_PART)
    .when(checkOrder())
    .perform(deliverOrderAction);

  /**
   * 取消订单: 待支付、待发货、待收货 -> 待支付
   * externalTransitions : 用于多个流转的构建器
   */
  builder.externalTransitions()
    .fromAmong(OrderStatusEnum.PAY_ONLINE,OrderStatusEnum.WAITING_FOR_RECEIVED,OrderStatusEnum.WAITING_DELIVERY)
    .to(OrderStatusEnum.CANCEL)
    .on(OrderEventEnum.CANCEL_ORDER)
    .when(checkOrder())
    .perform(cancelOrderAction);