SpringBoot集成spring-statemachine状态机实现业务流程

import org.springframework.statemachine.state.State;
import org.springframework.statemachine.transition.Transition;
 
// 定义状态
enum OrderStates {
    NEW, PENDING, CONFIRMED, CANCELLED
}
 
// 定义事件
enum OrderEvents {
    NEW_ORDER, CONFIRM, CANCEL
}
 
// 状态机配置
public class OrderStateMachineConfig {
 
    public static void configure(StateMachineBuilder.Builder<OrderStates, OrderEvents> builder) {
        builder
            .externalTransition().from(OrderStates.NEW).to(OrderStates.PENDING).on(OrderEvents.NEW_ORDER)
            .when(newOrderGuard()).perform(newOrderAction())
            .and()
            .externalTransition().from(OrderStates.PENDING).to(OrderStates.CONFIRMED).on(OrderEvents.CONFIRM)
            .when(confirmOrderGuard()).perform(confirmOrderAction())
            .and()
            .externalTransition().from(OrderStates.PENDING).to(OrderStates.CANCELLED).on(OrderEvents.CANCEL)
            .when(cancelOrderGuard()).perform(cancelOrderAction());
    }
 
    // 这里只是示例，实际的Guard、Action需要根据业务逻辑实现
    private static Guard<OrderStates, OrderEvents> newOrderGuard() {
        return (ctx) -> true; // 示例：返回true表示条件满足
    }
 
    private static Action<OrderStates, OrderEvents> newOrderAction() {
        return (ctx) -> { /* 执行新订单的动作 */ };
    }
 
    // 其他Guard和Action的示例省略...
}
 
// 使用状态机的示例
public class OrderService {
 
    private StateMachine<OrderStates, OrderEvents> stateMachine;
 
    public OrderService(StateMachine<OrderStates, OrderEvents> stateMachine) {
        this.stateMachine = stateMachine;
    }
 
    public void processEvent(OrderEvents event) {
        stateMachine.start(); // 启动状态机
        stateMachine.sendEvent(event); // 处理事件
    }
}

这个简单的例子展示了如何使用Spring State Machine来定义和配置一个订单处理的状态机。在实际的业务场景中，Guard和Action需要根据具体的业务逻辑来实现。