如何处理多条件订单状态的变化方式？

Question

在一个点餐系统中，有着外卖单，堂食单等。对应不同的订单与不同的动作和设置会有不同的状态变化，在代码中if elseif要写30-40多行，对于这种情况是否有更好的处理方法？

举例如下：
判断项：商家开启先食后付 是否自动接单 是否有打印机 打印是否成功 是否自动清台
动作： 下单 接单 拒单 顾客取消单 顾客支付 清台 结账
状态： 待确认 待处理 拒绝 完成 取消 进行中 超时 申请退款

如上由5种判断项 组合出多种变化 在每种变化中 不同的动作 改变订单不同的状态，像这种状态模型，除了无数的 if elseif 是否有更好的方法实现？

想要实现：输入动作 输出状态

想要一个思路，非常感谢！

Answer 1

给一个大概思路吧。java实现。可以稍微参考下。package com.ui;import java.util.ArrayList;import java.util.Arrays;import java.util.HashMap;import java.util.HashSet;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Set;public class OrderStatusService {&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 映射关系列表&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; public&nbsp; static List<OrderStatusMapper> mapperList = new ArrayList<OrderStatusMapper>();&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; static {&nbsp; &nbsp; &nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;* 初始化判断项、订单动作到状态的映射，这里只为演示，实际中映射关系最好保存在配置文件中或者数据库中，一般在应用启动的时候，从配置文件或者数据库加载，保存一份即可。&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; &nbsp; &nbsp; OrderStatusMapper m1 = new OrderStatusMapper();&nbsp; &nbsp; &nbsp; &nbsp; m1.addJudgementItems(1,2,4,6) //先吃后付 and 自动接单 and 有打印机 and 打印成功&nbsp; &nbsp; &nbsp; &nbsp; .addAction2statusItem(1,6)//下单动作:进行中&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; .addAction2statusItem(7, 4); //结账动作:已完成&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; OrderStatusMapper m2 = new OrderStatusMapper();&nbsp; &nbsp; &nbsp; &nbsp; m2.addJudgementItems(3,5)&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; .addAction2statusItem(2,1)&nbsp; &nbsp; &nbsp; &nbsp; .addAction2statusItem(4, 3);&nbsp;&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; mapperList.add(m1);&nbsp; &nbsp; &nbsp; &nbsp; mapperList.add(m2);&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; }&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 是否是相等的set&nbsp; &nbsp; &nbsp;* @param source&nbsp;&nbsp; &nbsp; &nbsp;* @param dest&nbsp; &nbsp; &nbsp;* @return&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; public boolean&nbsp; isEqualSet(Set<Integer> source,Set<Integer> dest){&nbsp; &nbsp; &nbsp; &nbsp; if(null == source || null == dest){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return false;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; if(source.size() != dest.size()){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return false;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; for(Iterator<Integer> it = source.iterator();it.hasNext();){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if(!dest.contains(it.next())){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return false;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; return true;&nbsp; &nbsp; }&nbsp; &nbsp; public static void main(String[] args) {&nbsp; &nbsp; &nbsp; &nbsp; Order order = new Order();&nbsp; &nbsp; &nbsp; &nbsp; order.setOrderAction(1);//下单&nbsp; &nbsp; &nbsp; &nbsp; order.setJudgementItems(new HashSet<Integer>(Arrays.asList(1,2,4,6)));//先吃后付 and 自动接单 and 有打印机 and 打印成功&nbsp; &nbsp; &nbsp; &nbsp; //获取订单下一个状态&nbsp; &nbsp; &nbsp; &nbsp; System.out.println(new OrderStatusService().getNextOrderStatus(order));//&nbsp; 结果为 6(进行中)&nbsp; &nbsp; }&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 获取下一个订单状态&nbsp; &nbsp; &nbsp;* @param curOrder&nbsp; &nbsp; &nbsp;* @return&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; public Integer getNextOrderStatus(Order curOrder){&nbsp; &nbsp; &nbsp; &nbsp; for(OrderStatusMapper mapper : mapperList){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if(isEqualSet(curOrder.getJudgementItems(), mapper.getJudgementItems()) &&&nbsp; null != curOrder.getOrderAction()){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return mapper.getAction2statusMap().get(curOrder.getOrderAction());&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; return null;&nbsp; &nbsp; }&nbsp; &nbsp;&nbsp;}/**&nbsp;* 订单类型，订单动作到状态的映射。&nbsp;*&nbsp;*/class OrderStatusMapper{&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 判断项&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; private Set<Integer> judgementItems = new HashSet<Integer>();&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 订单动作到状态关系&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; private Map<Integer,Integer> action2statusMap = new HashMap<Integer,Integer>();&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 下一个订单状态&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; private Integer nextStatus;&nbsp; &nbsp; public Set<Integer> getJudgementItems() {&nbsp; &nbsp; &nbsp; &nbsp; return judgementItems;&nbsp; &nbsp; }&nbsp; &nbsp; public OrderStatusMapper addJudgementItems(Integer ...items) {&nbsp; &nbsp; &nbsp; &nbsp; if(null == items || items.length <= 0){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return this;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; for(Integer cur : items){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; this.judgementItems.add(cur);&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; return this;&nbsp; &nbsp; }&nbsp; &nbsp;&nbsp; &nbsp; public Map<Integer, Integer> getAction2statusMap() {&nbsp; &nbsp; &nbsp; &nbsp; return action2statusMap;&nbsp; &nbsp; }&nbsp; &nbsp; public OrderStatusMapper addAction2statusItem(Integer action,Integer status) {&nbsp; &nbsp; &nbsp; &nbsp; if(null == action || null == status){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return this;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; this.action2statusMap.put(action, status);&nbsp; &nbsp; &nbsp; &nbsp; return this;&nbsp; &nbsp; }&nbsp; &nbsp; public Integer getNextStatus() {&nbsp; &nbsp; &nbsp; &nbsp; return nextStatus;&nbsp; &nbsp; }&nbsp; &nbsp; public OrderStatusMapper setNextStatus(Integer nextStatus) {&nbsp; &nbsp; &nbsp; &nbsp; this.nextStatus = nextStatus;&nbsp; &nbsp; &nbsp; &nbsp; return this;&nbsp; &nbsp; }}class Order{&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 判断项目&nbsp; &nbsp; &nbsp;* 1:商家开启先食后付 ;&nbsp; &nbsp; &nbsp;* 2:自动接单;&nbsp; &nbsp; &nbsp;* 3:不自动接单&nbsp; &nbsp; &nbsp;* 4:有打印机&nbsp; &nbsp; &nbsp;* 5:没有打印机&nbsp; &nbsp; &nbsp;* 6:打印成功&nbsp; &nbsp; &nbsp;* 7:打印不成功&nbsp; &nbsp; &nbsp;* 8:自动清台&nbsp; &nbsp; &nbsp;* 9:不自动清台&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; private Set<Integer> judgementItems;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 订单动作&nbsp; &nbsp; &nbsp;* 1:下单&nbsp;&nbsp; &nbsp; &nbsp;* 2:接单&nbsp;&nbsp; &nbsp; &nbsp;* 3:拒单&nbsp;&nbsp; &nbsp; &nbsp;* 4:顾客取消单&nbsp; &nbsp; &nbsp;* 5:顾客支付&nbsp;&nbsp; &nbsp; &nbsp;* 6:清台&nbsp; &nbsp; &nbsp;* 7:结账&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; private Integer orderAction;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; /**&nbsp; &nbsp; &nbsp;* 订单状态&nbsp; &nbsp; &nbsp;* 1:待确认&nbsp;&nbsp; &nbsp; &nbsp;* 2:待处理&nbsp;&nbsp; &nbsp; &nbsp;* 3:拒绝&nbsp;&nbsp; &nbsp; &nbsp;* 4:完成&nbsp;&nbsp; &nbsp; &nbsp;* 5:取消&nbsp;&nbsp; &nbsp; &nbsp;* 6:进行中&nbsp;&nbsp; &nbsp; &nbsp;* 7:超时&nbsp;&nbsp; &nbsp; &nbsp;* 8:申请退款&nbsp; &nbsp; &nbsp;*/&nbsp; &nbsp; private Integer orderStatus;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; public Set<Integer> getJudgementItems() {&nbsp; &nbsp; &nbsp; &nbsp; return judgementItems;&nbsp; &nbsp; }&nbsp; &nbsp; public void setJudgementItems(Set<Integer> judgementItems) {&nbsp; &nbsp; &nbsp; &nbsp; this.judgementItems = judgementItems;&nbsp; &nbsp; }&nbsp; &nbsp; public Integer getOrderAction() {&nbsp; &nbsp; &nbsp; &nbsp; return orderAction;&nbsp; &nbsp; }&nbsp; &nbsp; public void setOrderAction(Integer orderAction) {&nbsp; &nbsp; &nbsp; &nbsp; this.orderAction = orderAction;&nbsp; &nbsp; }&nbsp; &nbsp; public Integer getOrderStatus() {&nbsp; &nbsp; &nbsp; &nbsp; return orderStatus;&nbsp; &nbsp; }&nbsp; &nbsp; public void setOrderStatus(Integer orderStatus) {&nbsp; &nbsp; &nbsp; &nbsp; this.orderStatus = orderStatus;&nbsp; &nbsp; }}&nbsp;

Answer 2

试试看位运算可不可以, 每个比特位表示一个条件的状态.比如当前状态为: 0111某个动作的执行条件为: 0100 即只要第二个状态位为真的时候执行运算的时候就判断 0111 & 0100 == 0100 就可以判断这个动作要不要执行了这样每个动作对应一个 if, 会比原来少一点, 但是状态转换的代码可能会多一点, 这个就看楼主权衡了

Answer 3

状态切换和流程控制可以使用有限状态机定义与处理，相关开源的库也比较丰富。