用狀態(tài)機控制業(yè)務(wù)狀態(tài)扭轉(zhuǎn) Hello Spring StateMachine

轉(zhuǎn)載原文 : https://www.codetd.com/article/1010726
Spring StateMachine 官方文檔

一、狀態(tài)機

有限狀態(tài)機是一種用來進行對象行為建模的工具，其作用主要是描述對象在它的生命周期內(nèi)所經(jīng)歷的狀態(tài)序列，以及如何響應(yīng)來自外界的各種事件。在電商場景（訂單、物流、售后）、社交（IM消息投遞）、分布式集群管理（分布式計算平臺任務(wù)編排）等場景都有大規(guī)模的使用。

狀態(tài)機的要素：

狀態(tài)機可歸納為4個要素，現(xiàn)態(tài)、條件、動作、次態(tài)?！艾F(xiàn)態(tài)”和“條件”是因，“動作”和“次態(tài)”是果。

1 現(xiàn)態(tài)：指當(dāng)前所處的狀態(tài)
2 條件：又稱“事件”，當(dāng)一個條件被滿足，將會觸發(fā)一個動作，或者執(zhí)行一次狀態(tài)的遷移
3 動作：條件滿足后執(zhí)行的動作。動作執(zhí)行完畢后，可以遷移到新的狀態(tài)，也可以仍舊保持原狀態(tài)。動作不是必須的，當(dāng)條件滿足后，也可以不執(zhí)行任何動作，直接遷移到新的狀態(tài)。
4 次態(tài)：條件滿足后要遷往的新狀態(tài)?！按螒B(tài)”是相對于“現(xiàn)態(tài)”而言的，“次態(tài)”一旦被激活，就轉(zhuǎn)換成“現(xiàn)態(tài)”。

狀態(tài)機動作類型：

進入動作：在進入狀態(tài)時進行
退出動作：在退出狀態(tài)時進行
輸入動作：依賴于當(dāng)前狀態(tài)和輸入條件進行
轉(zhuǎn)移動作：在進行特定轉(zhuǎn)移時進行

二、spring statemachine

spring statemachine是使用 Spring框架下的狀態(tài)機概念創(chuàng)建的一種應(yīng)用程序開發(fā)框架。它使得狀態(tài)機結(jié)構(gòu)層次化，簡化了配置狀態(tài)機的過程。

例子一：簡單訂單流程

image

使用過程：

1 引入依賴

<dependency>
    <groupId>org.springframework.statemachine</groupId>
    <artifactId>spring-statemachine-core</artifactId>
    <version>2.2.0.RELEASE</version>
</dependency>

2 創(chuàng)建訂單狀態(tài)枚舉類和狀態(tài)轉(zhuǎn)換枚舉類

/**
 * 訂單狀態(tài)
 */
public enum OrderStatus {
    // 待支付，待發(fā)貨，待收貨，訂單結(jié)束
    WAIT_PAYMENT, WAIT_DELIVER, WAIT_RECEIVE, FINISH;
}
/**
 * 訂單狀態(tài)改變事件
 */
public enum OrderStatusChangeEvent {
    // 支付，發(fā)貨，確認收貨
    PAYED, DELIVERY, RECEIVED;
}

3 添加配置

/**
 * 訂單狀態(tài)機配置
 */
@Configuration
@EnableStateMachine(name = "orderStateMachine")
public class OrderStateMachineConfig extends StateMachineConfigurerAdapter<OrderStatus, OrderStatusChangeEvent> {

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

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

    /**
     * 持久化配置
     * 實際使用中，可以配合redis等，進行持久化操作
     * @return
     */
    @Bean
    public StateMachinePersister<OrderStatus, OrderStatusChangeEvent, Order> persister(){
        return new DefaultStateMachinePersister<>(new StateMachinePersist<OrderStatus, OrderStatusChangeEvent, Order>() {
            @Override
            public void write(StateMachineContext<OrderStatus, OrderStatusChangeEvent> context, Order order) throws Exception {
                //此處并沒有進行持久化操作
                System.out.println("持久化訂單信息, order = " + order);
            }

            @Override
            public StateMachineContext<OrderStatus, OrderStatusChangeEvent> read(Order order) throws Exception {
                //此處直接獲取order中的狀態(tài)，其實并沒有進行持久化讀取操作
                return new DefaultStateMachineContext<>(order.getStatus(), null, null, null);
            }
        });
    }
}

4 添加訂單狀態(tài)監(jiān)聽器

@Component("orderStateListener")
@WithStateMachine(name = "orderStateMachine")
public class OrderStateListenerImpl {

    @OnTransition(source = "WAIT_PAYMENT", target = "WAIT_DELIVER")
    public boolean payTransition(Message<OrderStatusChangeEvent> message) {
        Order order = (Order) message.getHeaders().get("order");
        Long payOrder = (Long) message.getHeaders().get("payOrder");
        Assert.isTrue(!StringUtils.isEmpty(payOrder), "payOrder不能為空");
        order.setPayOrder(payOrder);
        order.setStatus(OrderStatus.WAIT_DELIVER);
        System.out.println("支付 headers=" + message.getHeaders().toString());
        return true;
    }

    @OnTransition(source = "WAIT_DELIVER", target = "WAIT_RECEIVE")
    public boolean deliverTransition(Message<OrderStatusChangeEvent> message) {
        Order order = (Order) message.getHeaders().get("order");
        Long deliverOrder = (Long) message.getHeaders().get("deliverOrder");
        Assert.isTrue(!StringUtils.isEmpty(deliverOrder), "deliverOrder不能為空");
        order.setDeliverOrder(deliverOrder);
        order.setStatus(OrderStatus.WAIT_RECEIVE);
        System.out.println("發(fā)貨 headers=" + message.getHeaders().toString());
        return true;
    }

    @OnTransition(source = "WAIT_RECEIVE", target = "FINISH")
    public boolean receiveTransition(Message<OrderStatusChangeEvent> message) {
        Order order = (Order) message.getHeaders().get("order");
        Long confirmReceipt = (Long) message.getHeaders().get("confirmReceipt");
        Assert.isTrue(!StringUtils.isEmpty(confirmReceipt), "confirmReceipt不能為空");
        order.setConfirmReceipt(confirmReceipt);
        order.setStatus(OrderStatus.FINISH);
        System.out.println("收貨 headers=" + message.getHeaders().toString());
        return true;
    }
}

5 service中使用

@Service("orderService")
public class OrderServiceImpl implements OrderService {

    @Resource
    private StateMachine<OrderStatus, OrderStatusChangeEvent> orderStateMachine;

    @Resource
    private StateMachinePersister<OrderStatus, OrderStatusChangeEvent, Order> persister;

    private Long id = 1L;

    private final Map<Long, Order> orders = new HashMap<>();

    @Override
    public Order creat(Long skuId, Integer skuNum) {
        System.out.println(String.format("threadName=%s, 創(chuàng)建訂單, skuId = %s, skuNum = %s", Thread.currentThread().getName(), skuId, skuNum));
        Order order = new Order();
        order.setSkuId(skuId);
        order.setSkuNum(skuNum);
        order.setStatus(OrderStatus.WAIT_PAYMENT);
        order.setId(id++);
        orders.put(order.getId(), order);
        return order;
    }

    @Override
    public Order pay(Long id, Long payOrder) {
        Order order = orders.get(id);
        System.out.println(String.format("threadName=%s, 嘗試支付, id = %s, payOrder = %s", Thread.currentThread().getName(), id, payOrder));
        Message<OrderStatusChangeEvent> message = MessageBuilder.withPayload(OrderStatusChangeEvent.PAYED)
                .setHeader("order", order)
                .setHeader("payOrder", payOrder)
                .build();
        if (!sendEvent(message, order)) {
            System.out.println(String.format("threadName=%s, 支付失敗，狀態(tài)異常, id = %s, payOrder = %s", Thread.currentThread().getName(), id, payOrder));
        }
        return orders.get(id);
    }


    @Override
    public Order deliver(Long id, Long deliverOrder) {
        Order order = orders.get(id);
        System.out.println(String.format("threadName=%s, 嘗試發(fā)貨, id = %s, deliverOrder = %s", Thread.currentThread().getName(), id, deliverOrder));
        Message<OrderStatusChangeEvent> message = MessageBuilder.withPayload(OrderStatusChangeEvent.DELIVERY)
                .setHeader("order", order)
                .setHeader("deliverOrder", deliverOrder)
                .build();
        if (!sendEvent(message, orders.get(id))) {
            System.out.println(String.format("threadName=%s, 發(fā)貨失敗，狀態(tài)異常, id = %s, deliverOrder = %s", Thread.currentThread().getName(), id, deliverOrder));
        }
        return orders.get(id);
    }


    @Override
    public Order receive(Long id, Long confirmReceipt) {
        Order order = orders.get(id);
        System.out.println(String.format("threadName=%s, 嘗試收貨, id = %s, confirmReceipt = %s", Thread.currentThread().getName(), id, confirmReceipt));
        Message<OrderStatusChangeEvent> message = MessageBuilder.withPayload(OrderStatusChangeEvent.RECEIVED)
                .setHeader("order", order)
                .setHeader("confirmReceipt", confirmReceipt)
                .build();
        if (!sendEvent(message, orders.get(id))) {
            System.out.println(String.format("threadName=%s, 收貨失敗，狀態(tài)異常, id = %s, confirmReceipt = %s", Thread.currentThread().getName(), id, confirmReceipt));
        }
        return orders.get(id);
    }


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


    /**
     * 發(fā)送訂單狀態(tài)轉(zhuǎn)換事件
     *
     * @param message
     * @param order
     * @return
     */
    private synchronized boolean sendEvent(Message<OrderStatusChangeEvent> message, Order order) {
        boolean result = false;
        try {
            orderStateMachine.start();
            //嘗試恢復(fù)狀態(tài)機狀態(tài)
            persister.restore(orderStateMachine, order);
            //添加延遲用于線程安全測試
            Thread.sleep(1000);
            result = orderStateMachine.sendEvent(message);
            //持久化狀態(tài)機狀態(tài)
            persister.persist(orderStateMachine, order);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            orderStateMachine.stop();
        }
        return result;
    }
}

6 測試

@SpringBootTest
public class OrderServiceImplTest {

    @Autowired
    private OrderService orderService;

    @Test
    public void testMultThread() throws InterruptedException {
        Random randon = new Random();
        Order order1 = orderService.creat((long) randon.nextInt(999), randon.nextInt(999));
        Order order2 = orderService.creat((long) randon.nextInt(999), randon.nextInt(999));

        orderService.pay(order1.getId(), (long) randon.nextInt(999));

        new Thread(() -> {
            orderService.deliver(order1.getId(), (long) randon.nextInt(999));
            orderService.receive(order1.getId(), (long) randon.nextInt(999));
        }).start();

        orderService.pay(order2.getId(), (long) randon.nextInt(999));
        orderService.deliver(order2.getId(), (long) randon.nextInt(999));
        orderService.receive(order2.getId(), (long) randon.nextInt(999));

        Thread.currentThread().join(6 * 1000);

        System.out.println(orderService.getOrders());

    }

}

例子二：狀態(tài)機工廠

有些時候，一個狀態(tài)機不夠用，因為我們可能要處理多個訂單。這個時候就要用到了狀態(tài)機工廠。

1、不同線程啟用不同statemachine實例處理
2、用工廠模式創(chuàng)建statemachine，且用StateMachinePersist根據(jù)recruit對象不同狀態(tài)反序列化statemachine

1 配置修改

/**
 * 訂單狀態(tài)機配置
 */
@Configuration
@EnableStateMachineFactory(name = "orderStateMachineFactory")
public class OrderStateMachineConfig extends EnumStateMachineConfigurerAdapter<OrderStatus, OrderStatusChangeEvent> {

    /**
     * 訂單狀態(tài)機ID
     */
    public static final String orderStateMachineId = "orderStateMachineId";

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

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

    /**
     * 持久化配置
     * 實際使用中，可以配合redis等，進行持久化操作
     *
     * @return
     */
    @Bean
    public StateMachinePersister<OrderStatus, OrderStatusChangeEvent, Order> persister() {
        return new DefaultStateMachinePersister<>(new StateMachinePersist<OrderStatus, OrderStatusChangeEvent, Order>() {
            @Override
            public void write(StateMachineContext<OrderStatus, OrderStatusChangeEvent> context, Order order) throws Exception {
                //此處并沒有進行持久化操作
                order.setStatus(context.getState());
                System.out.println("持久化訂單信息, order = " + order);
            }

            @Override
            public StateMachineContext<OrderStatus, OrderStatusChangeEvent> read(Order order) throws Exception {
                //此處直接獲取order中的狀態(tài)，其實并沒有進行持久化讀取操作
                StateMachineContext<OrderStatus, OrderStatusChangeEvent> result = new DefaultStateMachineContext<>(order.getStatus(), null, null, null, null, orderStateMachineId);
                return result;
            }
        });
    }
}

2 service中使用

@Service("orderService")
public class OrderServiceImpl implements OrderService {

    @Resource
    private StateMachineFactory<OrderStatus, OrderStatusChangeEvent> orderStateMachineFactory;

    @Resource
    private StateMachinePersister<OrderStatus, OrderStatusChangeEvent, Order> persister;

    private Long id = 1L;

    private final Map<Long, Order> orders = new HashMap<>();

    @Override
    public Order creat(Long skuId, Integer skuNum) {
        System.out.println(String.format("threadName=%s, 創(chuàng)建訂單, skuId = %s, skuNum = %s", Thread.currentThread().getName(), skuId, skuNum));
        Order order = new Order();
        order.setSkuId(skuId);
        order.setSkuNum(skuNum);
        order.setStatus(OrderStatus.WAIT_PAYMENT);
        order.setId(id++);
        orders.put(order.getId(), order);
        return order;
    }

    @Override
    public Order pay(Long id, Long payOrder) {
        Order order = orders.get(id);
        System.out.println(String.format("threadName=%s, 嘗試支付, id = %s, payOrder = %s", Thread.currentThread().getName(), id, payOrder));
        Message<OrderStatusChangeEvent> message = MessageBuilder.withPayload(OrderStatusChangeEvent.PAYED)
                .setHeader("order", order)
                .setHeader("payOrder", payOrder)
                .build();
        if (!sendEvent(message, order)) {
            System.out.println(String.format("threadName=%s, 支付失敗，狀態(tài)異常, id = %s, payOrder = %s", Thread.currentThread().getName(), id, payOrder));
        }
        return orders.get(id);
    }


    @Override
    public Order deliver(Long id, Long deliverOrder) {
        Order order = orders.get(id);
        System.out.println(String.format("threadName=%s, 嘗試發(fā)貨, id = %s, deliverOrder = %s", Thread.currentThread().getName(), id, deliverOrder));
        Message<OrderStatusChangeEvent> message = MessageBuilder.withPayload(OrderStatusChangeEvent.DELIVERY)
                .setHeader("order", order)
                .setHeader("deliverOrder", deliverOrder)
                .build();
        if (!sendEvent(message, orders.get(id))) {
            System.out.println(String.format("threadName=%s, 發(fā)貨失敗，狀態(tài)異常, id = %s, deliverOrder = %s", Thread.currentThread().getName(), id, deliverOrder));
        }
        return orders.get(id);
    }


    @Override
    public Order receive(Long id, Long confirmReceipt) {
        Order order = orders.get(id);
        System.out.println(String.format("threadName=%s, 嘗試收貨, id = %s, confirmReceipt = %s", Thread.currentThread().getName(), id, confirmReceipt));
        Message<OrderStatusChangeEvent> message = MessageBuilder.withPayload(OrderStatusChangeEvent.RECEIVED)
                .setHeader("order", order)
                .setHeader("confirmReceipt", confirmReceipt)
                .build();
        if (!sendEvent(message, orders.get(id))) {
            System.out.println(String.format("threadName=%s, 收貨失敗，狀態(tài)異常, id = %s, confirmReceipt = %s", Thread.currentThread().getName(), id, confirmReceipt));
        }
        return orders.get(id);
    }


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


    /**
     * 發(fā)送訂單狀態(tài)轉(zhuǎn)換事件
     *
     * @param message
     * @param order
     * @return
     */
    private boolean sendEvent(Message<OrderStatusChangeEvent> message, Order order) {
        synchronized (String.valueOf(order.getId()).intern()) {
            boolean result = false;
            StateMachine<OrderStatus, OrderStatusChangeEvent> orderStateMachine = orderStateMachineFactory.getStateMachine(OrderStateMachineConfig.orderStateMachineId);
            System.out.println("id=" + order.getId() + " 狀態(tài)機 orderStateMachine" + orderStateMachine);
            try {
                orderStateMachine.start();
                //嘗試恢復(fù)狀態(tài)機狀態(tài)
                persister.restore(orderStateMachine, order);
                System.out.println("id=" + order.getId() + " 狀態(tài)機 orderStateMachine id=" + orderStateMachine.getId());
                //添加延遲用于線程安全測試
                Thread.sleep(1000);
                result = orderStateMachine.sendEvent(message);
                //持久化狀態(tài)機狀態(tài)
                persister.persist(orderStateMachine, order);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                orderStateMachine.stop();
            }
            return result;
        }
    }
}

3 listener中配置id

@Component("orderStateListener")@WithStateMachine(id = OrderStateMachineConfig.orderStateMachineId)public class OrderStateListenerImpl {    @OnTransition(source = "WAIT_PAYMENT", target = "WAIT_DELIVER")    public boolean payTransition(Message<OrderStatusChangeEvent> message) {        Order order = (Order) message.getHeaders().get("order");        Long payOrder = (Long) message.getHeaders().get("payOrder");        Assert.isTrue(!StringUtils.isEmpty(payOrder), "payOrder不能為空");        order.setPayOrder(payOrder);        order.setStatus(OrderStatus.WAIT_DELIVER);        System.out.println("支付 headers=" + message.getHeaders().toString());        return true;    }    @OnTransition(source = "WAIT_DELIVER", target = "WAIT_RECEIVE")    public boolean deliverTransition(Message<OrderStatusChangeEvent> message) {        Order order = (Order) message.getHeaders().get("order");        Long deliverOrder = (Long) message.getHeaders().get("deliverOrder");        Assert.isTrue(!StringUtils.isEmpty(deliverOrder), "deliverOrder不能為空");        order.setDeliverOrder(deliverOrder);        order.setStatus(OrderStatus.WAIT_RECEIVE);        System.out.println("發(fā)貨 headers=" + message.getHeaders().toString());        return true;    }    @OnTransition(source = "WAIT_RECEIVE", target = "FINISH")    public boolean receiveTransition(Message<OrderStatusChangeEvent> message) {        Order order = (Order) message.getHeaders().get("order");        Long confirmReceipt = (Long) message.getHeaders().get("confirmReceipt");        Assert.isTrue(!StringUtils.isEmpty(confirmReceipt), "confirmReceipt不能為空");        order.setConfirmReceipt(confirmReceipt);        order.setStatus(OrderStatus.FINISH);        System.out.println("收貨 headers=" + message.getHeaders().toString());        return true;    }}
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