/**
 * @description: 抽象狀態(tài)類
 */
public abstract class MyState {
    abstract void handler();
}

/**
 * @description: 具體狀態(tài)A
 */
public class RedLightState extends MyState{

    @Override
    void handler() {
        System.out.println("紅燈停");
    }
}

/**
 * @description: 具體狀態(tài)B
 */
public class GreenLightState extends MyState{

    @Override
    void handler() {
        System.out.println("綠燈行");
    }
}

/**
 * @description: 環(huán)境類
 */
public class MyContext {

    private MyState state;

    public void setState(MyState state) {
        this.state = state;
    }

    public void handler() {
        state.handler();
    }
}

/**
 * @description: 測(cè)試狀態(tài)模式
 */
public class TestStateModel {
    public static void main(String[] args) {
        MyContext myContext = new MyContext();

        RedLightState redLightState = new RedLightState();
        GreenLightState greenLightState = new GreenLightState();

        myContext.setState(redLightState);
        myContext.handler(); //紅燈停

        myContext.setState(greenLightState);
        myContext.handler(); //綠燈行
    }
}

<dependency>
    <groupId>org.springframework.statemachine</groupId>
    <artifactId>spring-statemachine-core</artifactId>
    <version>${springboot.version}</version>
</dependency>

/**
 * @description: 模擬訂單類
 */
@Data
public class Order {
    private Long orderId;
    private OrderStatusEnum orderStatus;
}

/**
 * @description: 訂單狀態(tài)
 */
public enum OrderStatusEnum {
    // 待支付
    WAIT_PAYMENT,
    // 待發(fā)貨
    WAIT_DELIVER,
    // 待收貨
    WAIT_RECEIVE,
    // 完成
    FINISH;
}

/**
 * @description:訂單狀態(tài)轉(zhuǎn)換行為
 */
public enum OrderStatusChangeEventEnum {
    //支付
    PAYED,
    //發(fā)貨
    DELIVERY,
    //收貨
    RECEIVED;
}

/**
 * @description: 訂單狀態(tài)機(jī)
 */
@Configuration
@EnableStateMachine
public class OrderStatusMachineConfig extends StateMachineConfigurerAdapter<OrderStatusEnum, OrderStatusChangeEventEnum> {

    /**
     * 配置狀態(tài)
     */
    @Override
    public void configure(StateMachineStateConfigurer<OrderStatusEnum, OrderStatusChangeEventEnum> states) throws Exception {
        states.withStates()
                .initial(OrderStatusEnum.WAIT_PAYMENT)
                .end(OrderStatusEnum.FINISH)
                .states(EnumSet.allOf(OrderStatusEnum.class));
    }

    /**
     * 配置狀態(tài)轉(zhuǎn)換事件關(guān)系
     */
    @Override
    public void configure(StateMachineTransitionConfigurer<OrderStatusEnum, OrderStatusChangeEventEnum> transitions) throws Exception {
        transitions.withExternal().source(OrderStatusEnum.WAIT_PAYMENT).target(OrderStatusEnum.WAIT_DELIVER)
                .event(OrderStatusChangeEventEnum.PAYED)
                .and()
                .withExternal().source(OrderStatusEnum.WAIT_DELIVER).target(OrderStatusEnum.WAIT_RECEIVE)
                .event(OrderStatusChangeEventEnum.DELIVERY)
                .and()
                .withExternal().source(OrderStatusEnum.WAIT_RECEIVE).target(OrderStatusEnum.FINISH)
                .event(OrderStatusChangeEventEnum.RECEIVED);
    }
}

/**
 * @description: 狀態(tài)監(jiān)聽
 */
@Component
@WithStateMachine
@Transactional
public class OrderStatusListener {
    @OnTransition(source = "WAIT_PAYMENT", target = "WAIT_DELIVER")
    public boolean payTransition(Message message) {
        Order order = (Order) message.getHeaders().get("order");
        order.setOrderStatus(OrderStatusEnum.WAIT_DELIVER);
        System.out.println("支付，狀態(tài)機(jī)反饋信息：" + message.getHeaders().toString());
        return true;
    }

    @OnTransition(source = "WAIT_DELIVER", target = "WAIT_RECEIVE")
    public boolean deliverTransition(Message message) {
        Order order = (Order) message.getHeaders().get("order");
        order.setOrderStatus(OrderStatusEnum.WAIT_RECEIVE);
        System.out.println("發(fā)貨，狀態(tài)機(jī)反饋信息：" + message.getHeaders().toString());
        return true;
    }

    @OnTransition(source = "WAIT_RECEIVE", target = "FINISH")
    public boolean receiveTransition(Message message) {
        Order order = (Order) message.getHeaders().get("order");
        order.setOrderStatus(OrderStatusEnum.FINISH);
        System.out.println("收貨，狀態(tài)機(jī)反饋信息：" + message.getHeaders().toString());
        return true;
    }

}

/**
 * @description: 訂單服務(wù)
 */
@Service
public class OrderServiceImpl implements OrderService {

    @Resource
    private StateMachine<OrderStatusEnum, OrderStatusChangeEventEnum> orderStateMachine;

    private long id = 1L;

    private Map<Long, Order> orders = Maps.newConcurrentMap();

    @Override
    public Order create() {
        Order order = new Order();
        order.setOrderStatus(OrderStatusEnum.WAIT_PAYMENT);
        order.setOrderId(id++);
        orders.put(order.getOrderId(), order);
        System.out.println("訂單創(chuàng)建成功:" + order.toString());
        return order;
    }

    @Override
    public Order pay(long id) {
        Order order = orders.get(id);
        System.out.println("嘗試支付，訂單號(hào)：" + id);
        Message message = MessageBuilder.withPayload(OrderStatusChangeEventEnum.PAYED).
                setHeader("order", order).build();
        if (!sendEvent(message)) {
            System.out.println(" 支付失敗, 狀態(tài)異常，訂單號(hào)：" + id);
        }
        return orders.get(id);
    }

    @Override
    public Order deliver(long id) {
        Order order = orders.get(id);
        System.out.println(" 嘗試發(fā)貨，訂單號(hào)：" + id);
        if (!sendEvent(MessageBuilder.withPayload(OrderStatusChangeEventEnum.DELIVERY)
                .setHeader("order", order).build())) {
            System.out.println(" 發(fā)貨失敗，狀態(tài)異常，訂單號(hào)：" + id);
        }
        return orders.get(id);
    }

    @Override
    public Order receive(long id) {
        Order order = orders.get(id);
        System.out.println(" 嘗試收貨，訂單號(hào)：" + id);
        if (!sendEvent(MessageBuilder.withPayload(OrderStatusChangeEventEnum.RECEIVED)
                .setHeader("order", order).build())) {
            System.out.println(" 收貨失敗，狀態(tài)異常，訂單號(hào)：" + id);
        }
        return orders.get(id);
    }


    @Override
    public Map<Long, Order> getOrders() {
        return orders;
    }

    /**
     * 發(fā)送狀態(tài)轉(zhuǎn)換事件
     * @param message
     * @return
     */
    private synchronized boolean sendEvent(Message<OrderStatusChangeEventEnum> message) {
        boolean result = false;
        try {
            orderStateMachine.start();
            result = orderStateMachine.sendEvent(message);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (Objects.nonNull(message)) {
                Order order = (Order) message.getHeaders().get("order");
                if (Objects.nonNull(order) && Objects.equals(order.getOrderStatus(), OrderStatusEnum.FINISH)) {
                    orderStateMachine.stop();
                }
            }
        }
        return result;
    }
}

@RestController
public class OrderController {

    @Resource
    private OrderService orderService;

    @RequestMapping("/testOrderStatusChange")
    public String testOrderStatusChange(){
        orderService.create();
        orderService.create();
        orderService.pay(1L);
        orderService.deliver(1L);
        orderService.receive(1L);
        orderService.pay(2L);
        orderService.deliver(2L);
        orderService.receive(2L);
        System.out.println("全部訂單狀態(tài)：" + orderService.getOrders());
        return "success";
    }

}