1俩功、多個狀態(tài)機的搞法

?? 在實際的企業(yè)應用中，基本不可能只有一個狀態(tài)機流程在跑碰声，比如訂單诡蜓，肯定是很多個訂單在運行，每個訂單都有自己的訂單狀態(tài)機流程胰挑，但上一章的例子万牺，大家可以試一下，當執(zhí)行到一個狀態(tài)時洽腺，再次刷新頁面脚粟，不會有任何日志出現(xiàn)，當一個狀態(tài)流程執(zhí)行到某個狀態(tài)蘸朋，再次執(zhí)行這個狀態(tài)核无，是不會有任何輸出的，因為狀態(tài)機的機制是只有在狀態(tài)切換的時候才會事件（event）觸發(fā)藕坯，所以我們這一章講多個狀態(tài)機的并行執(zhí)行团南。

?? 首先，靠上一章例子里面的手打定制一個StateMachineConfig的做法炼彪，就只能是有一個狀態(tài)機流程制霸整個項目吐根，這種霸道的做法肯定是不行啦，要想多個狀態(tài)機流程并行辐马，那么就要請builder出場了拷橘，看代碼：

private final static String MACHINEID = "orderMachine";
public StateMachine<OrderStates, OrderEvents> build(BeanFactory beanFactory) throws Exception {
         StateMachineBuilder.Builder<OrderStates, OrderEvents> builder = StateMachineBuilder.builder();
         
         System.out.println("構(gòu)建訂單狀態(tài)機");
         
         builder.configureConfiguration()
                .withConfiguration()
                .machineId(MACHINEID)
                .beanFactory(beanFactory);
         
         builder.configureStates()
                    .withStates()
                    .initial(OrderStates.UNPAID)
                    .states(EnumSet.allOf(OrderStates.class));
                    
         builder.configureTransitions()
                     .withExternal()
                        .source(OrderStates.UNPAID).target(OrderStates.WAITING_FOR_RECEIVE)
                        .event(OrderEvents.PAY).action(action())
                        .and()
                    .withExternal()
                        .source(OrderStates.WAITING_FOR_RECEIVE).target(OrderStates.DONE)
                        .event(OrderEvents.RECEIVE);
                    
         return builder.build();
     }

??有沒有似曾相識的感覺，里面描述訂單狀態(tài)機的初始狀態(tài)喜爷，狀態(tài)機的流程代碼和StateMachineConfig幾乎是一樣的冗疮，但是都配置在StateMachineBuilder里面

StateMachineBuilder.Builder<OrderStates, OrderEvents> builder = StateMachineBuilder.builder();

這是完整的builder類代碼：

import java.util.EnumSet;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.statemachine.StateContext;
import org.springframework.statemachine.StateMachine;
import org.springframework.statemachine.action.Action;
import org.springframework.statemachine.config.StateMachineBuilder;
import org.springframework.stereotype.Component;

@Component
public class OrderStateMachineBuilder {

    private final static String MACHINEID = "orderMachine";
    
     /**
      * 構(gòu)建狀態(tài)機
      * 
     * @param beanFactory
     * @return
     * @throws Exception
     */
    public StateMachine<OrderStates, OrderEvents> build(BeanFactory beanFactory) throws Exception {
         StateMachineBuilder.Builder<OrderStates, OrderEvents> builder = StateMachineBuilder.builder();
         
         System.out.println("構(gòu)建訂單狀態(tài)機");
         
         builder.configureConfiguration()
                .withConfiguration()
                .machineId(MACHINEID)
                .beanFactory(beanFactory);
         
         builder.configureStates()
                    .withStates()
                    .initial(OrderStates.UNPAID)
                    .states(EnumSet.allOf(OrderStates.class));
                    
         builder.configureTransitions()
                     .withExternal()
                        .source(OrderStates.UNPAID).target(OrderStates.WAITING_FOR_RECEIVE)
                        .event(OrderEvents.PAY).action(action())
                        .and()
                    .withExternal()
                        .source(OrderStates.WAITING_FOR_RECEIVE).target(OrderStates.DONE)
                        .event(OrderEvents.RECEIVE);
                    
         return builder.build();
     }
    
    @Bean
    public Action<OrderStates, OrderEvents> action() {
        return new Action<OrderStates, OrderEvents>() {

            @Override
            public void execute(StateContext<OrderStates, OrderEvents> context) {
               System.out.println(context);
            }
        };
    }

    
}

??在完整的代碼里面我們看到有個東西沒講，那就是MACHINEID檩帐，在builder的配置代碼里面术幔，有這么一段

builder.configureConfiguration()
                .withConfiguration()
                .machineId(MACHINEID)
                .beanFactory(beanFactory);

machineId是狀態(tài)機的配置類和事件實現(xiàn)類的關聯(lián)，和它關聯(lián)的是OrderEventConfig湃密，代碼如下：

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.messaging.Message;
import org.springframework.statemachine.annotation.OnTransition;
import org.springframework.statemachine.annotation.WithStateMachine;

@WithStateMachine(id="orderMachine")
public class OrderEventConfig {
private Logger logger = LoggerFactory.getLogger(getClass());
    
    /**
     * 當前狀態(tài)UNPAID
     */
    @OnTransition(target = "UNPAID")
    public void create() {
        logger.info("---訂單創(chuàng)建诅挑，待支付---");
    }
    
    ......

}

這個后面的內(nèi)容和上一章的OrderSingleEventConfig一模一樣四敞，但在類的上面注解了這一句：

@WithStateMachine(id="orderMachine")

這個id對應的就是OrderStateMachineBuilder 里面的MACHINEID，被builder寫到.machineId(MACHINEID)里面拔妥。這樣目养，OrderStateMachineBuilder對應上一章的StateMachineConfig多個狀態(tài)機的實現(xiàn)版本，OrderEventConfig對應上一章的OrderSingleEventConfig毒嫡，基本一樣，只是和OrderStateMachineBuilder通過machineid做了關聯(lián)』锰荩現(xiàn)在我們來看怎么用上它兜畸。
在controller里面引用這個類：

@Autowired
    private OrderStateMachineBuilder orderStateMachineBuilder;

然后使用它

@RequestMapping("/testOrderState")
    public void testOrderState(String orderId) throws Exception {

        StateMachine<OrderStates, OrderEvents> stateMachine = orderStateMachineBuilder.build(beanFactory);

        // 創(chuàng)建流程
        stateMachine.start();

        // 觸發(fā)PAY事件
        stateMachine.sendEvent(OrderEvents.PAY);

        // 觸發(fā)RECEIVE事件
        stateMachine.sendEvent(OrderEvents.RECEIVE);


        // 獲取最終狀態(tài)
        System.out.println("最終狀態(tài)：" + stateMachine.getState().getId());
    }

??這其實就是每次請求testOrderState就會生成一個新的statemachine，所以每次刷新testOrderState請求都會看到日志顯示：

構(gòu)建訂單狀態(tài)機
orderMachine
2019-05-03 19:24:23.734  INFO 11752 --- [nio-9991-exec-1] tConfig$$EnhancerBySpringCGLIB$$29e58541 : ---訂單創(chuàng)建碘梢，待支付---
2019-05-03 19:24:23.754  INFO 11752 --- [nio-9991-exec-1] o.s.s.support.LifecycleObjectSupport     : started org.springframework.statemachine.support.DefaultStateMachineExecutor@133d52dd
2019-05-03 19:24:23.755  INFO 11752 --- [nio-9991-exec-1] o.s.s.support.LifecycleObjectSupport     : started UNPAID DONE WAITING_FOR_RECEIVE  / UNPAID / uuid=52b44103-22af-49cc-a645-3aab29212a9e / id=orderMachine
DefaultStateContext [stage=TRANSITION, message=GenericMessage [payload=PAY, headers={id=ed826b85-e069-9a5e-34a1-d78454183143, timestamp=1556882663765}], messageHeaders={id=ade4055c-9b59-6498-501e-0e2a8cfe04b4, _sm_id_=52b44103-22af-49cc-a645-3aab29212a9e, timestamp=1556882663767}, extendedState=DefaultExtendedState [variables={}], transition=AbstractTransition [source=ObjectState [getIds()=[UNPAID], getClass()=class org.springframework.statemachine.state.ObjectState, hashCode()=1027927242, toString()=AbstractState [id=UNPAID, pseudoState=org.springframework.statemachine.state.DefaultPseudoState@4b05dcc, deferred=[], entryActions=[], exitActions=[], stateActions=[], regions=[], submachine=null]], target=ObjectState [getIds()=[WAITING_FOR_RECEIVE], getClass()=class org.springframework.statemachine.state.ObjectState, hashCode()=422378, toString()=AbstractState [id=WAITING_FOR_RECEIVE, pseudoState=null, deferred=[], entryActions=[], exitActions=[], stateActions=[], regions=[], submachine=null]], kind=EXTERNAL, guard=null], stateMachine=UNPAID DONE WAITING_FOR_RECEIVE  / UNPAID / uuid=52b44103-22af-49cc-a645-3aab29212a9e / id=orderMachine, source=null, target=null, sources=null, targets=null, exception=null]
傳遞的參數(shù)：null
2019-05-03 19:24:23.775  INFO 11752 --- [nio-9991-exec-1] tConfig$$EnhancerBySpringCGLIB$$29e58541 : ---用戶完成支付咬摇，待收貨---
傳遞的參數(shù)：null
傳遞的參數(shù)：null
2019-05-03 19:24:23.782  INFO 11752 --- [nio-9991-exec-1] tConfig$$EnhancerBySpringCGLIB$$29e58541 : ---用戶已收貨，訂單完成---
最終狀態(tài)：DONE

??這和之前執(zhí)行testSingleOrderState是不一樣的煞躬，testSingleOrderState只有第一次會有日志打出肛鹏，再執(zhí)行就沒有日志出來了，而testOrderState因為每次都build一個新的statemachine恩沛，所以每次都會顯示日志出來在扰，這樣就能保證每個訂單都可以為它build一個新的statemachine，就解決了多個狀態(tài)機并行執(zhí)行的問題了雷客。

??雖然多個狀態(tài)機的問題解決了芒珠，但是對于實際的企業(yè)應用而言，還是有問題搅裙。這種簡單粗暴的皱卓，來一個請求就新增一個狀態(tài)機的搞法很不經(jīng)濟，而且狀態(tài)機也不是越多越好部逮，而應該是和業(yè)務對象一一對應才行娜汁，比如訂單，就是一個訂單一個狀態(tài)機兄朋，而不是每次訂單變化就build的一個掐禁。這個問題就用到了狀態(tài)機的持久化，我們下一章就談談持久化問題颅和。

2穆桂、有個坑

EventConfig類的@WithStateMachine注解有兩個參數(shù)可用

public @interface WithStateMachine {

    /**
     * The name of a state machine bean which annotated bean should be associated.
     * Defaults to {@code stateMachine}
     *
     * @return the state machine bean name
     */
    String name() default StateMachineSystemConstants.DEFAULT_ID_STATEMACHINE;

    /**
     * The id of a state machine which annotated bean should be associated.
     *
     * @return the state machine id
     * @see StateMachine#getId()
     */
    String id() default "";
}

??我們在上面是用id來關聯(lián)StateMachineBuilder和EventConfig的，用name是無效的融虽，但這個id是spring-statemachine-starter享完，2.x版本才有，在1.x版本里面有额，只有name參數(shù)般又，用name參數(shù)StateMachineBuilder和EventConfig關聯(lián)不上彼绷，也就是在builder里面狀態(tài)變化，eventConfig里面并不會同步觸發(fā)事件茴迁，請大家確認使用的是2.x的版本寄悯，這都是我血與淚的忠告。

3.新例子

??在上一個例子中堕义，我們實現(xiàn)了多個狀態(tài)機并存執(zhí)行猜旬，不同的訂單有各自的狀態(tài)機運行，但只有一種狀態(tài)機倦卖，這顯然不能滿足實際業(yè)務的要求洒擦，比如我就遇到了訂單流程和公文審批流程在同一個項目的情況，所以我們這一章講怎么讓多種狀態(tài)機共存怕膛。
我們先把上一章的例子狀態(tài)機再復習一下熟嫩，這是個訂單狀態(tài)機，流程圖如下：

image

??定義這個狀態(tài)機我們用到了OrderEvents褐捻，OrderStates來表達狀態(tài)（states）和事件（events）掸茅，用OrderStateMachineBuilder來描述初始狀態(tài)和狀態(tài)變化流程，用OrderEventConfig來描述這個流程和狀態(tài)變化過程中需要做的業(yè)務∧眩現(xiàn)在我們再弄一個新的狀態(tài)機流程昧狮，表單狀態(tài)機，流程圖如下：

image

??為此板壮，我們同樣配套了和訂單狀態(tài)機一樣的表單四件套陵且，events，states个束，StateMachineBuilder和eventConfig慕购。

public enum FormStates {
    BLANK_FORM, // 空白表單
    FULL_FORM, // 填寫完表單
    CONFIRM_FORM, // 校驗表單
    SUCCESS_FORM// 成功表單
}

public enum FormEvents {
    WRITE, // 填寫
    CONFIRM, // 校驗
    SUBMIT // 提交
}

import java.util.EnumSet;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.statemachine.StateMachine;
import org.springframework.statemachine.config.StateMachineBuilder;
import org.springframework.stereotype.Component;

/**
 * 訂單狀態(tài)機構(gòu)建器
 */
@Component
public class FormStateMachineBuilder {

    private final static String MACHINEID = "formMachine";

     /**
      * 構(gòu)建狀態(tài)機
      * 
     * @param beanFactory
     * @return
     * @throws Exception
     */
    public StateMachine<FormStates, FormEvents> build(BeanFactory beanFactory) throws Exception {
         StateMachineBuilder.Builder<FormStates, FormEvents> builder = StateMachineBuilder.builder();

         System.out.println("構(gòu)建表單狀態(tài)機");

         builder.configureConfiguration()
                .withConfiguration()
                .machineId(MACHINEID)
                .beanFactory(beanFactory);

         builder.configureStates()
                    .withStates()
                    .initial(FormStates.BLANK_FORM)
                    .states(EnumSet.allOf(FormStates.class));

         builder.configureTransitions()
                     .withExternal()
                        .source(FormStates.BLANK_FORM).target(FormStates.FULL_FORM)
                        .event(FormEvents.WRITE)
                        .and()
                    .withExternal()
                        .source(FormStates.FULL_FORM).target(FormStates.CONFIRM_FORM)
                        .event(FormEvents.CONFIRM)
                        .and()
                    .withExternal()
                        .source(FormStates.CONFIRM_FORM).target(FormStates.SUCCESS_FORM)
                        .event(FormEvents.SUBMIT);

         return builder.build();
     }

}

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.messaging.Message;
import org.springframework.statemachine.annotation.OnTransition;
import org.springframework.statemachine.annotation.WithStateMachine;

@WithStateMachine(id="formMachine")
public class FormEventConfig {
private Logger logger = LoggerFactory.getLogger(getClass());

    /**
     * 當前狀態(tài)BLANK_FORM
     */
    @OnTransition(target = "BLANK_FORM")
    public void create() {
        logger.info("---空白表單---");
    }

    /**
     * BLANK_FORM->FULL_FORM 執(zhí)行的動作
     */
    @OnTransition(source = "BLANK_FORM", target = "FULL_FORM")
    public void write(Message<FormEvents> message) {
        logger.info("---填寫完表單---");
    }

    /**
     * FULL_FORM->CONFIRM_FORM 執(zhí)行的動作
     */
    @OnTransition(source = "FULL_FORM", target = "CONFIRM_FORM")
    public void confirm(Message<FormEvents> message) {
        logger.info("---校驗表單---");
    }

    /**
     * CONFIRM_FORM->SUCCESS_FORM 執(zhí)行的動作
     */
    @OnTransition(source = "CONFIRM_FORM", target = "SUCCESS_FORM")
    public void submit(Message<FormEvents> message) {
        logger.info("---表單提交成功---");
    }

}

從代碼可以看到深深的套路感，里面除了對流程狀態(tài)的描述不同外茬底，另外一個不同點就是MACHINEID沪悲，在不同的狀態(tài)機流程中，用MACHINEID來標識不同就能使用多種狀態(tài)機了阱表，對比一下就很清楚殿如。在builder里面通過MACHINEID來區(qū)分

private final static String MACHINEID = "orderMachine";

    public StateMachine<OrderStates, OrderEvents> build(BeanFactory beanFactory) throws Exception {
         StateMachineBuilder.Builder<OrderStates, OrderEvents> builder = StateMachineBuilder.builder();

         System.out.println("構(gòu)建訂單狀態(tài)機");

         builder.configureConfiguration()
                .withConfiguration()
                .machineId(MACHINEID)
                .beanFactory(beanFactory);
...

private final static String MACHINEID = "formMachine";

    public StateMachine<FormStates, FormEvents> build(BeanFactory beanFactory) throws Exception {
         StateMachineBuilder.Builder<FormStates, FormEvents> builder = StateMachineBuilder.builder();

         System.out.println("構(gòu)建表單狀態(tài)機");

         builder.configureConfiguration()
                .withConfiguration()
                .machineId(MACHINEID)
                .beanFactory(beanFactory);
...

對應的在eventconfig里面

@WithStateMachine(id="orderMachine")
public class OrderEventConfig {
...

@WithStateMachine(id="formMachine")
public class FormEventConfig {

通過@WithStateMachine注解的id參數(shù)就區(qū)分出來了不同的狀態(tài)機，這個id就是builder里面定義的MACHINEID最爬。然后就是怎么引用的問題了涉馁，我們來看controller

    @Autowired
    private OrderStateMachineBuilder orderStateMachineBuilder;

    @Autowired
    private FormStateMachineBuilder formStateMachineBuilder;

這樣，不同的builder就能同時引用爱致，兩種狀態(tài)機就互不干擾的各自運行了烤送，這是運行的代碼：

@RequestMapping("/testOrderState")
    public void testOrderState(String orderId) throws Exception {

        StateMachine<OrderStates, OrderEvents> stateMachine = orderStateMachineBuilder.build(beanFactory);
        System.out.println(stateMachine.getId());

        // 創(chuàng)建流程
        stateMachine.start();

        // 觸發(fā)PAY事件
        stateMachine.sendEvent(OrderEvents.PAY);

        // 觸發(fā)RECEIVE事件
        stateMachine.sendEvent(OrderEvents.RECEIVE);

        // 獲取最終狀態(tài)
        System.out.println("最終狀態(tài)：" + stateMachine.getState().getId());
    }

    @RequestMapping("/testFormState")
    public void testFormState() throws Exception {

        StateMachine<FormStates, FormEvents> stateMachine = formStateMachineBuilder.build(beanFactory);
        System.out.println(stateMachine.getId());

        // 創(chuàng)建流程
        stateMachine.start();

        stateMachine.sendEvent(FormEvents.WRITE);

        stateMachine.sendEvent(FormEvents.CONFIRM);

        stateMachine.sendEvent(FormEvents.SUBMIT);

        // 獲取最終狀態(tài)
        System.out.println("最終狀態(tài)：" + stateMachine.getState().getId());
    }

分別執(zhí)行
http://localhost:9991/statemachine/testOrderState 使用StateMachineBuilder創(chuàng)建的多個狀態(tài)機演示
http://localhost:9991/statemachine/testFormState 多種狀態(tài)機的演示（上面都是order的狀態(tài)機，這個是form的狀態(tài)機）
在日志里面就能看到各自狀態(tài)機的運行結(jié)果了糠悯。
目前為止帮坚，多個狀態(tài)機和多種狀態(tài)機都可以在spring statemachine里面實現(xiàn)了妻往，下一章我們來解決下狀態(tài)機和實際業(yè)務間的數(shù)據(jù)傳輸問題，畢竟我們不是為了讓狀態(tài)機自個獨自玩耍试和，和業(yè)務數(shù)據(jù)互通有無才是企業(yè)開發(fā)的正道讯泣。

spring statemachine-多個狀態(tài)機共存

spring statemachine-多個狀態(tài)機共存

1俩功、多個狀態(tài)機的搞法

2穆桂、有個坑

3.新例子