状态机+策略在工单流转里的使用

2022/08/24 34点热度 0人点赞 0条评论

昨天刚写了 可编排策略在交易系统的应用,今天小伙伴就给我提了个需求。

背景

最近由于新业务的需要,需要对原有工单的推单逻辑进行变动。我是想着尽可能不对原有逻辑进行改动,毕竟业务还一直在跑,就开启了一个小模块进行代码的组合。

在设计评审中,我一直强调要设计的灵活些。

校验规则一定要原子化,然后可编排在任何一处场景。校验的的入参和出参必须抽取,并标准化。

直接把我昨天写的文章扔过去了。

然后就差一个状态机了,得我就把框架搭起来。

设计

工单的流转完全可以状态驱动,如果发现两个状态都指向了一个处理逻辑,那就说明,你需要加一个状态。本着这个原则开始设计。

执行策略的实现

首先定义工单状态策略

/**
 * 工单状态流转策略
 * @Author: yxkong
 * @Date: 2022/8/23 11:28 AM
 * @version: 1.0
 */
public interface OrderStateStrategy {

    /**
     * 状态流转前置校验
     * @param context
     * @return
     */
    OrderStateResult check(OrderStateContext context);

    /**
     * 状态流转统一入口
     *   执行的模板
     * @param context
     * @return
     */
    OrderStateResult execute(OrderStateContext context);

    /**
     * 状态流转处理器,由各个策略实现
     *   如果需要重试,在code = -1的时候,retry = true
     * @param context
     * @return
     */
    OrderStateResult handler(OrderStateContext context);

    /**
     * 状态流转后置处理
     * @param context
     * @param rst
     * @return
     */
    boolean after(OrderStateContext context, OrderStateResult rst);
}

进行模板方法封装,将整个公共部分抽取

/**
 * 公共处理
 * @Author: yxkong
 * @Date: 2022/8/23 11:47 AM
 * @version: 1.0
 */
public abstract class AbstractOrderStateStrategy implements OrderStateStrategy {

    @Override
    public OrderStateResult check(OrderStateContext context) {
        /**
         * 此处公共校验
         * 根据工单id查询工单的状态
         */
        OrderStateEnum dbStatus = OrderStateEnum.init;
        if (context.getCurrentState() != dbStatus){
            return new OrderStateResult(null,false,CodeStateEnum.fail,"当前状态不匹配");
        }
        return new OrderStateResult(CodeStateEnum.succ,"校验通过!");
    }

    @Override
    public OrderStateResult execute(OrderStateContext context) {
        OrderStateResult check = check(context);
        if (!check.isSucc()){
            /**
             * 这块埋点,因为什么拦截的
             */
            return check ;
        }
        OrderStateResult handler = handler(context);
        //执行后的统一处理
        boolean rst = this.after(context, handler);
        if (!rst){
            /**
             * 要保证最终一致性,这里业务已经处理完了
             * 记录日志或者,推入消息队列做补偿
             */
        }
        return handler;
    }

    @Override
    public boolean after(OrderStateContext context, OrderStateResult rst) {
        /**
         *  统一发送领域事件
         *  统一记录日志,失败也需要记录日志
         *  处理成功,返回true,处理失败,返回false,需要补偿
         */
        return false;
    }
}

具体的策略实现

/**
 * 关单策略实现
 * @Author: yxkong
 * @Date: 2022/8/23 12:16 PM
 * @version: 1.0
 */
@Service("closeOrderStrategy")
public class CloseOrderStrategyImpl extends AbstractOrderStateStrategy {
    @Override
    public OrderStateResult handler(OrderStateContext context) {
        return null;
    }
}

/**
 * 推单策略实现
 * @Author: yxkong
 * @Date: 2022/8/23 11:59 AM
 * @version: 1.0
 */
@Service("pushOrderStrategy")
public class PushOrderStrategyImpl extends AbstractOrderStateStrategy {
    @Override
    public OrderStateResult check(OrderStateContext context) {
        /**
         * 定制化拦截
         * 比如,查询推单开关是否开启,重试的次数
         */
        String closeSwitch = "open";
        if ("close".equals(closeSwitch)){
            return  new OrderStateResult(CodeStateEnum.fail,"推单开关关闭,不允许推单");
        }
        return super.check(context);
    }

    @Override
    public OrderStateResult handler(OrderStateContext context) {
        /**
         * 推单的处理逻辑
         */
        return null;
    }
}

/**
 * 重新路由策略实现
 * @Author: yxkong
 * @Date: 2022/8/23 12:10 PM
 * @version: 1.0
 */
@Service("reRouteStrategy")
public class ReRouteStrategyImpl extends AbstractOrderStateStrategy {
    @Override
    public OrderStateResult handler(OrderStateContext context) {
        /**
         * 路由到具体的机构后,将数据库工单改成推单状态
         */
        return new OrderStateResult(OrderStateEnum.pass, CodeStateEnum.succ,"路由成功");
    }
}

最后类结构如下:

image-20220823181005766

状态机的实现

状态机接口定义

/**
 * 状态机服务
 * @Author: yxkong
 * @Date: 2022/8/23 5:40 PM
 * @version: 1.0
 */
public interface OrderStateMachineService {
    /**
     * 状态机执行
     * @param context
     * @return
     */
    OrderStateResult execute(OrderStateContext context);
}

状态机实现

/**
 * 工单状态机
 * @Author: yxkong
 * @Date: 2022/8/23 12:32 PM
 * @version: 1.0
 */
@Service
public class OrderStateMachineServiceImpl implements OrderStateMachineService {
    @Autowired
    private Map<String, OrderStateStrategy> map;

    /**
     * 状态机执行
     * @param context
     * @return
     */
    @Override
    public OrderStateResult execute(OrderStateContext context){
        OrderStateEnum currentState = context.getCurrentState();
        if ( OrderStateEnum.isFinalState(currentState)){
            //终态不处理,直接返回
            return null;
        }
        OrderStateMappingEnum mapping = OrderStateMappingEnum.of(currentState.getState());
        if (mapping == null){
            throw new RuntimeException("暂不支持该状态的处理"+ currentState);
        }
        //获取对应状态的处理策略
        OrderStateStrategy stateStrategy = map.get(mapping.getHandlerBean());
        //执行具体的策略
        OrderStateResult execute = stateStrategy.execute(context);
        //是否需要递归调用
        if (execute.isExecute()){
            /**
             * 一个状态执行完,重新赋值状态
             */
            context.setCurrentState(execute.getOrderStatus());
            context.setRetry(execute.isRetry());
            return this.execute(context);
        }
        return execute;
    }
}

在这里利用spring的DI机制,将同类型的注入到map里,方便使用

同时利用枚举来封装状态与处理器的关系。

枚举类:

/**
 * 状态与处理映射
 * @author yxkong
 */
public enum OrderStateMappingEnum {
    closeOrder(5,"closeOrderStrategy","关单"),
    reroute(1,"reRouteStrategy","重新路由"),
    retry(2,"retryStrategy", "重试"),
    blockOrder(3,"blockOrderStrategy", "卡单");
    private int state;
    private String handlerBean;
    private String desc;

    OrderStateMappingEnum(int state, String handlerBean, String desc) {
        this.state = state;
        this.handlerBean = handlerBean;
        this.desc = desc;
    }

    public int getState() {
        return state;
    }

    public String getHandlerBean() {
        return handlerBean;
    }

    public String getDesc() {
        return desc;
    }

    /**
     * 获取枚举
     *
     * @param state 枚举值
     * @return OrderStateMappingEnum
     */
    public static OrderStateMappingEnum of(final int state) {
        for (final OrderStateMappingEnum s : OrderStateMappingEnum.values()) {
            if (Objects.equals(s.state, state)) {
                return s;
            }
        }
        return null;
    }

}

/**
 * 状态枚举
 * @Author: yxkong
 * @Date: 2022/8/23 11:41 AM
 * @version: 1.0
 */
public enum OrderStateEnum {
    init(0,"初始化工单"),
    waitingClose(8,"等待关闭"),
    waitingRoute(2,"等待路由"),
    refuse(6,"工单拒绝"),
    pass(5,"工单通过");

    private int state;
    private String desc;

    private OrderStateEnum(int state, String desc) {
        this.state = state;
        this.desc = desc;
    }
    public static OrderStateEnum of(final int state) {
        for (final OrderStateEnum s : OrderStateEnum.values()) {
            if (Objects.equals(s.state, state)) {
                return s;
            }
        }
        return null;
    }

    /**
     * 是否终态
     * @param state
     * @return
     */
    public static boolean isFinalState(OrderStateEnum state){
        return OrderStateEnum.refuse.equals(state) || OrderStateEnum.pass.equals(state);
    }

    public int getState() {
        return state;
    }

    public String getDesc() {
        return desc;
    }
}

/**
 * 返回code枚举
 * @Author: yxkong
 * @Date: 2022/8/23 5:56 PM
 * @version: 1.0
 */
public enum CodeStateEnum {
    succ(1,"成功"),
    fail(0,"失败"),
    error(-1,"异常");
    private int code;
    private String desc;

    private CodeStateEnum(int code, String desc) {
        this.code = code;
        this.desc = desc;
    }
    public static CodeStateEnum of(final int code) {
        for (final CodeStateEnum s : CodeStateEnum.values()) {
            if (Objects.equals(s.code, code)) {
                return s;
            }
        }
        return null;
    }

    public int getCode() {
        return code;
    }

    public String getDesc() {
        return desc;
    }
}

上下文与出参

/**
 * 工单状态上下文
 * @Author: yxkong
 * @Date: 2022/8/23 11:28 AM
 * @version: 1.0
 */
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class OrderStateContext {
    /**工单id*/
    private String appId;
    /**当前状态*/
    private OrderStateEnum currentState;
    /**重试*/
    private boolean retry;
}

/**
 * 状态流转返回结果
 *
 * @Author: yxkong
 * @Date: 2022/8/23 11:30 AM
 * @version: 1.0
 */
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class OrderStateResult {
    /**执行后的工单状态*/
    private OrderStateEnum orderStatus;
    /**是否重试*/
    private boolean retry ;
    /**当前执行状态码  1成功,0失败,-1 异常*/
    private CodeStateEnum code;
    /**当前执行结果描述*/
    private String message;

    public OrderStateResult(CodeStateEnum code, String message) {
        this.code = code;
        this.message = message;
    }

    public OrderStateResult(OrderStateEnum orderStatus, CodeStateEnum code, String message) {
        this.orderStatus = orderStatus;
        this.code = code;
        this.message = message;
    }

    /**
     * 是否成功
     * @return
     */
    public boolean isSucc(){
        return this.code == CodeStateEnum.succ;
    }
    /**
     * 是否继续执行
     * @return
     */
    public boolean isExecute(){
        if (CodeStateEnum.succ == this.code  || (CodeStateEnum.error == this.code && retry)){
            return Boolean.TRUE;
        }
        return Boolean.FALSE;
    }
}

整个代码结构如下:

image-20220823182045689

这么一来,我们只需要关心具体的业务逻辑就行了,状态不够就加状态,入口统一,关系映射在一处,也方便排查问题。

这里不像上一篇里的规则,定义以后可以用在多个地方,每个地方,我都可以编排。

这里就是一对一的映射。

yxkong

这个人很懒,什么都没留下

文章评论

watch series online watch series Watch The Sandman 2022 Free Online Watch All or Nothing: Arsenal 2022 Free Online Watch The Black Phone 2021 Free Online