一,数据源

1.1,数据库查出来的数据是

两张表先各自左外连接,然后在相互左外连接查找省市县的数据(业务需求必须这样做,省市去的是第一张表,而市县取的是第二张表,两张表中间通过市的名字连接)见这个博文的最后一张图片

1.2,要求转换成的json格式的数据

1.2.1,完整数据

json省市县数据源(这是全部的数据)

1.2.2,抽取的数据

 [
     {
         "Code": "410000",
         "Name": "河南省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "郑州市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "二七区",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "中原区",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             },
             {
                 "Code": "414530",
                 "Name": "新乡市",
                 "level": [
                     {
                         "Code": "414530",
                         "Name": "卫滨区",
                         "sort": 1
                     },
                     {
                         "Code": "414530",
                         "Name": "牧野区",
                         "sort": 2
                     }
                 ],
                 "sort": 2
             }
         ]
     },
     {
         "Code": "410000",
         "Name": "陕西省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "汉中市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "西乡县",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "南郑县",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             },
             {
                 "Code": "414530",
                 "Name": "宝鸡市",
                 "level": [
                     {
                         "Code": "414530",
                         "Name": "岐山县",
                         "sort": 1
                     },
                     {
                         "Code": "414530",
                         "Name": "芙蓉县",
                         "sort": 2
                     }
                 ],
                 "sort": 2
             }
         ]
     }
 ]

二,转化的整体代码

2.1,代码总览

   /**
      * 查询省份城市区县
      *
      * @return
      */
     public String queryFullZoneInfo() {
         List<Map<String, String>> mapList = zoneInfoService.queryFullZoneInfo();
         List<Map<String, Object>> zoneList = new ArrayList<Map<String, Object>>();
         Map<String, Object> existMap = new HashMap<String, Object>();
         for (Map<String, String> map : mapList) {
             String province = map.get("province");
             Map<String, Object> provinceMap = null;
             if (existMap.containsKey(province)) {
                 provinceMap = (Map<String, Object>) existMap.get(province);
             } else {
                 provinceMap = new HashMap<String, Object>();
                 existMap.put(province, provinceMap);
                 zoneList.add(provinceMap);
             }

             provinceMap.put("Code", map.get("provinceCode"));
             provinceMap.put("Name", map.get("province"));
             String city = map.get("city");
             if (StringUtils.isNotEmpty(city)) {
                 List<Map<String, Object>> provinceCityList = null;
                 if (existMap.containsKey(province + "_")) {
                     provinceCityList = (List<Map<String, Object>>) existMap.get(province + "_");
                 } else {
                     provinceCityList = new ArrayList<Map<String, Object>>();
                     existMap.put(province + "_", provinceCityList);
                     provinceMap.put("level", provinceCityList);
                 }
                 Map<String, Object> provinceCityMap = null;
                 if (existMap.containsKey(province + "_" + city)) {
                     provinceCityMap = (Map<String, Object>) existMap.get(province + "_" + city);
                 } else {
                     provinceCityMap = new HashMap<String, Object>();
                     existMap.put(province + "_" + city, provinceCityMap);
                     provinceCityList.add(provinceCityMap);
                     String citySort = String.valueOf(existMap.get(province + "_sort"));
                     existMap.put(province + "_sort", "null".equals(citySort) ? 1 : NumberUtils.toInt(citySort) + 1);
                     provinceCityMap.put("sort", existMap.get(province + "_sort"));
                 }

                 provinceCityMap.put("Name", city);
                 provinceCityMap.put("Code", map.get("cityCode"));

                 List<Map<String, Object>> provinceCityCountryList = null;
                 if (existMap.containsKey(province + "_" + city + "_")) {
                     provinceCityCountryList = (List<Map<String, Object>>) existMap.get(province + "_" + city + "_");
                 } else {
                     provinceCityCountryList = new ArrayList<Map<String, Object>>();
                     existMap.put(province + "_" + city + "_", provinceCityCountryList);
                     provinceCityMap.put("level", provinceCityCountryList);
                 }

                 String country = map.get("country");
                 Map<String, Object> provinceCityCountryMap = null;
                 if (StringUtils.isNotEmpty(country)) {
                     if (existMap.containsKey(province + "_" + city + "_" + country)) {
                         provinceCityCountryMap = (Map<String, Object>) existMap.get(province + "_" + city + "_" + country);
                     } else {
                         provinceCityCountryMap = new HashMap<String, Object>();
                         existMap.put(province + "_" + city + "_" + country, provinceCityCountryMap);
                         provinceCityCountryList.add(provinceCityCountryMap);
                         String countrySort = String.valueOf(existMap.get(province + "_" + city + "_sort"));
                         existMap.put(province + "_" + city + "_sort", "null".equals(countrySort) ? 1 : NumberUtils.toInt(countrySort) + 1);
                         provinceCityCountryMap.put("sort", existMap.get(province + "_" + city + "_sort"));
                     }

                     provinceCityCountryMap.put("Code", map.get("countryCode"));
                     provinceCityCountryMap.put("Name", country);
                 } else {
                     provinceCityCountryMap = new HashMap<String, Object>();
                     provinceCityCountryList.add(provinceCityCountryMap);
                     provinceCityCountryMap.put("sort", 1);
                     provinceCityCountryMap.put("Code", "");
                     provinceCityCountryMap.put("Name", "");
                 }
             }
         }

         try {
             return JsonUtils.toJson(zoneList);
         } catch (Exception e) {
             e.printStackTrace();
         }

         return null;
     }

三,代码解析

3.1,json格式数据分析

从1.2.2的数据我们可以看到这个json所要求的数据是这个样子的

3.1.1,list

第一个大的list里面装的是34个省的对象组成的一个list集合。

3.1.2,map(对象)

每一个省中有code,和name的键值对,还有一个level的list集合

3.1.3,list

就是上面所说的level的集合,这个集合当中装的是每一个省里面的地级市的map对象

3.1.4,map(对象)

map对象里面有code,name的键值对,还有一个level的list集合,此外还有一个代表顺序的sort标示符

3.1.5,list

就是上面所说的level的集合,这个集合当中装的是每一个地级市里面装的县城的map对象

3.1.6,map(对象)

map对象里面有code,name的键值对,此外还有一个代表顺序的sort标示符,注意这个里面是没有list的集合了,因为它已经是最后一层了。

3.2,java代码分析

3.2.1,代码初步实现

根据上面的代码我们可以写出这样的代码

  public String queryFullZoneInfo() {
         List<Map<String, String>> mapList = zoneInfoService.queryFullZoneInfo();
         List<Map<String, Object>> zoneList = new ArrayList<Map<String, Object>>();
         Map<String, Object> existMap = new HashMap<String, Object>();
         Map<String, Object> provinceMap = new HashMap<String, Object>();
         Map<String, Object> provinceCityMap = new HashMap<String, Object>();
         List<Map<String, Object>> provinceCityList = new ArrayList<Map<String, Object>>();
         List<Map<String, Object>> provinceCityCountryList = new ArrayList<Map<String, Object>>();
         Map<String, Object> provinceCityCountryMap = new HashMap<String, Object>();
         for (Map<String, String> map : mapList) {
         zoneList = new ArrayList<Map<String, Object>>();
          provinceMap = new HashMap<String, Object>();
           provinceCityMap = new HashMap<String, Object>();
             provinceMap.put("Code", map.get("provinceCode"));
             provinceCityList = new ArrayList<Map<String, Object>>();
             provinceCityCountryList = new ArrayList<Map<String, Object>>();
             provinceCityCountryMap = new HashMap<String, Object>();
             provinceMap.put("Name", map.get("province"));

provinceMap.put("level", provinceCityList);

provinceCityList.add(provinceCityMap);

provinceCityMap.put("Name", map.get("city")); provinceCityMap.put("Code", map.get("cityCode"));

provinceCityMap.put("level", provinceCityCountryList);

provinceCityCountryList.add(provinceCityCountryMap);

provinceCityCountryMap.put("Code", map.get("countryCode")); provinceCityCountryMap.put("Name", map.get("country")); zoneList.add(provinceMap); } try { return JsonUtils.toJson(zoneList); } catch (Exception e) { e.printStackTrace(); }

注意上面空开的空格是和4.2做对比用的。

3.2.2,注意点

在上面的代码中虽然provinceMap是先把provinceCityList给put进去的,但是这不影响后面provinceCityList的取值,换句话就是当执行到这句

provinceMap.put("level", provinceCityList);

代码的时候,provinceCityList是null,只到这句代码

provinceCityList.add(provinceCityMap);
provinceCityMap.put("Name", map.get("city"));
provinceCityMap.put("Code", map.get("cityCode"));

执行完之后它才有的值,但同时注意了,provinceMap里面的provinceCityList也就有了值,这是后面给它赋值的。

3.2.3,注意点升级

 String province = map.get("province");
             Map<String, Object> provinceMap = null;
             if (existMap.containsKey(province)) {
                 provinceMap = (Map<String, Object>) existMap.get(province);
             } else {
                 provinceMap = new HashMap<String, Object>();
                 existMap.put(province, provinceMap);{黑龙江省={Name=黑龙江省, Code=230000}}
                 zoneList.add(provinceMap);
             }

             provinceMap.put("Code", map.get("provinceCode"));
             provinceMap.put("Name", map.get("province"));
             注意理解上面的代码:
             是先申明了一个map,注意第一遍走的时候existMap.put(province, provinceMap);它是空的
             但是当走到provinceMap.put("Code", map.get("provinceCode"));
             provinceMap.put("Name", map.get("province"));这两行的时候它会把值给塞进去,
             这时候existMap里面有值了
             即使如果不走else里面的语句,也会把值给塞进去的。

3.2.4,问题点

假如像上面那样去解决问题的话,那么后面的代码永远会把前面的代码给覆盖掉的,

因为每一次都是new的一个对象。所以到最后上万条的数据,只会出来最后一条数据,

比如我测试的结果

 [
     {
         "Code": "310000",
         "Name": "上海市",
         "level": [
             {
                 "Code": "310100",
                 "Name": "上海市",
                 "level": [
                     {
                         "Code": "2909",
                         "Name": "长宁区"
                     }
                 ]
             }
         ]
     }
 ]

最后返回的就是这一条数据,完全不是自己要的东西。

四,解决方法

4.1,代码

和2.1的代码是一么一样的。

4.2,注意点

这句代码就是在原来的基础上加了一个existMap的双例集合

我们把2.1的代码分开来读就会更加清晰

 if (existMap.containsKey(province + "_")) {
                     provinceCityList = (List<Map<String, Object>>) existMap.get(province + "_");
                 } else {
                     provinceCityList = new ArrayList<Map<String, Object>>();
                     existMap.put(province + "_", provinceCityList);
                     provinceMap.put("level", provinceCityList);
                 }
 if (existMap.containsKey(province + "_" + city)) {
                     provinceCityMap = (Map<String, Object>) existMap.get(province + "_" + city);
                 } else {
                     provinceCityMap = new HashMap<String, Object>();
                     existMap.put(province + "_" + city, provinceCityMap);
                     provinceCityList.add(provinceCityMap);
                     String citySort = String.valueOf(existMap.get(province + "_sort"));
                     existMap.put(province + "_sort", "null".equals(citySort) ? 1 : NumberUtils.toInt(citySort) + 1);
                     provinceCityMap.put("sort", existMap.get(province + "_sort"));
                 }
 if (existMap.containsKey(province + "_" + city + "_")) {
                     provinceCityCountryList = (List<Map<String, Object>>) existMap.get(province + "_" + city + "_");
                 } else {
                     provinceCityCountryList = new ArrayList<Map<String, Object>>();
                     existMap.put(province + "_" + city + "_", provinceCityCountryList);
                     provinceCityMap.put("level", provinceCityCountryList);
                 }
 if (existMap.containsKey(province + "_" + city + "_" + country)) {
                         provinceCityCountryMap = (Map<String, Object>) existMap.get(province + "_" + city + "_" + country);
                     } else {
                         provinceCityCountryMap = new HashMap<String, Object>();
                         existMap.put(province + "_" + city + "_" + country, provinceCityCountryMap);
                         provinceCityCountryList.add(provinceCityCountryMap);
                         String countrySort = String.valueOf(existMap.get(province + "_" + city + "_sort"));
                         existMap.put(province + "_" + city + "_sort", "null".equals(countrySort) ? 1 : NumberUtils.toInt(countrySort) + 1);
                         provinceCityCountryMap.put("sort", existMap.get(province + "_" + city + "_sort"));
                     }

4.3,解析existMap作用

因为假如现在没有这个map集合就会产生覆盖的作用,现在这个map的作用就是把取出来的值以不同的名字取出来放到map集合中来,假如下一次再去取的时候如果有就不在新建对象了,直接用原来的就行了,如果没有在建立新的对象。

这就解决了覆盖的问题。

同时也给sort排上了序号。

用下面的例子来说明

有就取原来的,没有就新建,这样的话就会把后面新的数据加到前面有的数据里面
举个例子,假如现在是河南省map1里面有name,code,和sort,leval集合,第一遍是地级市是安阳,当第二遍循环的时候,还是取省份这时候还是河南省,就不会新建一个map了,而是还是取原来的map1,这时候假如是新乡市,就会把新乡市,同样加在这个map当中,这样一个map当中就会有两个leval了
假如现在不是河南省了,而是陕西省了,就会新建一个map2,会把它里面的数据加载这个map2当中,
map1,map2装在一个list中返回,就有效的避免了第一种情况的产生了。

其中市县和上面也是同样的道理。

注意这个existMap里面装的数据会特别的多,比返回的provinceMap大了几万倍呢。

我们以上面的json的数据来手动遍历几遍。

4.3.1,首次遍历

 {
     "Code": "410000",
     "Name": "河南省",
     "level": [
         {
             "Code": "414500",
             "Name": "郑州市",
             "level": [
                 {
                     "Code": "414500",
                     "Name": "二七区",
                     "sort": 1
                 }
             ],
             "sort": 1
         }
     ]
 }

4.3.2,2遍

 {
     "Code": "410000",
     "Name": "河南省",
     "level": [
         {
             "Code": "414500",
             "Name": "郑州市",
             "level": [
                 {
                     "Code": "414500",
                     "Name": "二七区",
                     "sort": 1
                 },
                 {
                     "Code": "414500",
                     "Name": "中原区",
                     "sort": 2
                 }
             ],
             "sort": 1
         }
     ]
 }

4.3.3,3遍

 {
     "Code": "410000",
     "Name": "河南省",
     "level": [
         {
             "Code": "414500",
             "Name": "郑州市",
             "level": [
                 {
                     "Code": "414500",
                     "Name": "二七区",
                     "sort": 1
                 },
                 {
                     "Code": "414500",
                     "Name": "中原区",
                     "sort": 2
                 }
             ],
             "sort": 1
         },
         {
             "Code": "414530",
             "Name": "新乡市",
             "level": [
                 {
                     "Code": "414530",
                     "Name": "卫滨区",
                     "sort": 1
                 }
             ],
             "sort": 2
         }
     ]
 }

4.3.4,4遍

 {
     "Code": "410000",
     "Name": "河南省",
     "level": [
         {
             "Code": "414500",
             "Name": "郑州市",
             "level": [
                 {
                     "Code": "414500",
                     "Name": "二七区",
                     "sort": 1
                 },
                 {
                     "Code": "414500",
                     "Name": "中原区",
                     "sort": 2
                 }
             ],
             "sort": 1
         },
         {
             "Code": "414530",
             "Name": "新乡市",
             "level": [
                 {
                     "Code": "414530",
                     "Name": "卫滨区",
                     "sort": 1
                 },
                 {
                     "Code": "414530",
                     "Name": "牧野区",
                     "sort": 2
                 }
             ],
             "sort": 2
         }
     ]
 }

4.3.5,5遍

 [
     {
         "Code": "410000",
         "Name": "河南省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "郑州市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "二七区",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "中原区",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             },
             {
                 "Code": "414530",
                 "Name": "新乡市",
                 "level": [
                     {
                         "Code": "414530",
                         "Name": "卫滨区",
                         "sort": 1
                     },
                     {
                         "Code": "414530",
                         "Name": "牧野区",
                         "sort": 2
                     }
                 ],
                 "sort": 2
             }
         ]
     },
     {
         "Code": "410000",
         "Name": "陕西省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "汉中市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "西乡县",
                         "sort": 1
                     }
                 ],
                 "sort": 1
             }
         ]
     }
 ]

4.3.6,6遍

 [
     {
         "Code": "410000",
         "Name": "河南省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "郑州市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "二七区",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "中原区",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             },
             {
                 "Code": "414530",
                 "Name": "新乡市",
                 "level": [
                     {
                         "Code": "414530",
                         "Name": "卫滨区",
                         "sort": 1
                     },
                     {
                         "Code": "414530",
                         "Name": "牧野区",
                         "sort": 2
                     }
                 ],
                 "sort": 2
             }
         ]
     },
     {
         "Code": "410000",
         "Name": "陕西省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "汉中市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "西乡县",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "南郑县",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             }
         ]
     }
 ]

4.3.7,7遍

 [
     {
         "Code": "410000",
         "Name": "河南省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "郑州市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "二七区",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "中原区",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             },
             {
                 "Code": "414530",
                 "Name": "新乡市",
                 "level": [
                     {
                         "Code": "414530",
                         "Name": "卫滨区",
                         "sort": 1
                     },
                     {
                         "Code": "414530",
                         "Name": "牧野区",
                         "sort": 2
                     }
                 ],
                 "sort": 2
             }
         ]
     },
     {
         "Code": "410000",
         "Name": "陕西省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "汉中市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "西乡县",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "南郑县",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             },
             {
                 "Code": "414530",
                 "Name": "宝鸡市",
                 "level": [
                     {
                         "Code": "414530",
                         "Name": "岐山县",
                         "sort": 1
                     }
                 ],
                 "sort": 2
             }
         ]
     }
 ]

4.3.8,8遍

 [
     {
         "Code": "410000",
         "Name": "河南省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "郑州市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "二七区",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "中原区",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             },
             {
                 "Code": "414530",
                 "Name": "新乡市",
                 "level": [
                     {
                         "Code": "414530",
                         "Name": "卫滨区",
                         "sort": 1
                     },
                     {
                         "Code": "414530",
                         "Name": "牧野区",
                         "sort": 2
                     }
                 ],
                 "sort": 2
             }
         ]
     },
     {
         "Code": "410000",
         "Name": "陕西省",
         "level": [
             {
                 "Code": "414500",
                 "Name": "汉中市",
                 "level": [
                     {
                         "Code": "414500",
                         "Name": "西乡县",
                         "sort": 1
                     },
                     {
                         "Code": "414500",
                         "Name": "南郑县",
                         "sort": 2
                     }
                 ],
                 "sort": 1
             },
             {
                 "Code": "414530",
                 "Name": "宝鸡市",
                 "level": [
                     {
                         "Code": "414530",
                         "Name": "岐山县",
                         "sort": 1
                     },
                     {
                         "Code": "414530",
                         "Name": "芙蓉县",
                         "sort": 2
                     }
                 ],
                 "sort": 2
             }
         ]
     }
 ]

致此一个流程走完就大概知道它的一个流程了。

五,优化

5.1,优化一

因为existMap数据是特别大的,所以每当我们遍历完一个省份之后就把里面的数据清除

 String province = map.get("province");
             Map<String, Object> provinceMap = null;
             if(province!=existMap.get("province")){
                 existMap.clear();
             }
             

拿这一次的取出来的province和existMap里面的province对比,假如有就继续遍历,假如没有就说明换省份了,清空exitMap,这样会提升效率。

5.2,优化二

最后一次就不用王existMap里面放值了,因为我们知道没遍历一次省市可能一样,但是县绝对是不一样的。

     String country = map.get("country");
                 Map<String, Object> provinceCityCountryMap = null;
                 if (StringUtils.isNotEmpty(country)) {

                         provinceCityCountryMap = new HashMap<String, Object>();
                         provinceCityCountryList.add(provinceCityCountryMap);
                         String countrySort = String.valueOf(existMap.get(province + "_" + city + "_sort"));
                         existMap.put(province + "_" + city + "_sort", "null".equals(countrySort) ? 1 : NumberUtils.toInt(countrySort) + 1);
                         provinceCityCountryMap.put("sort", existMap.get(province + "_" + city + "_sort"));

                     provinceCityCountryMap.put("Code", map.get("countryCode"));
                     provinceCityCountryMap.put("Name", country);

5.3,优化完之后完整的代码

   public String queryFullZoneInfo() {
         List<Map<String, String>> mapList = zoneInfoService.queryFullZoneInfo();
         List<Map<String, Object>> zoneList = new ArrayList<Map<String, Object>>();
         Map<String, Object> existMap = new HashMap<String, Object>();
         for (Map<String, String> map : mapList) {
             String province = map.get("province");
             Map<String, Object> provinceMap = null;
             if(province!=existMap.get("province")){
                 existMap.clear();
             }

             if (existMap.containsKey(province)) {
                 provinceMap = (Map<String, Object>) existMap.get(province);
             } else {
                 provinceMap = new HashMap<String, Object>();
                 existMap.put(province, provinceMap);
                 zoneList.add(provinceMap);
             }

             provinceMap.put("Code", map.get("provinceCode"));
             provinceMap.put("Name", map.get("province"));
             String city = map.get("city");
             if (StringUtils.isNotEmpty(city)) {
                 List<Map<String, Object>> provinceCityList = null;
                 if (existMap.containsKey(province + "_")) {
                     provinceCityList = (List<Map<String, Object>>) existMap.get(province + "_");
                 } else {
                     provinceCityList = new ArrayList<Map<String, Object>>();
                     existMap.put(province + "_", provinceCityList);
                     provinceMap.put("level", provinceCityList);
                 }
                 Map<String, Object> provinceCityMap = null;
                 if (existMap.containsKey(province + "_" + city)) {
                     provinceCityMap = (Map<String, Object>) existMap.get(province + "_" + city);
                 } else {
                     provinceCityMap = new HashMap<String, Object>();
                     existMap.put(province + "_" + city, provinceCityMap);
                     provinceCityList.add(provinceCityMap);
                     String citySort = String.valueOf(existMap.get(province + "_sort"));
                     existMap.put(province + "_sort", "null".equals(citySort) ? 1 : NumberUtils.toInt(citySort) + 1);
                     provinceCityMap.put("sort", existMap.get(province + "_sort"));
                 }

                 provinceCityMap.put("Name", city);
                 provinceCityMap.put("Code", map.get("cityCode"));

                 List<Map<String, Object>> provinceCityCountryList = null;
                 if (existMap.containsKey(province + "_" + city + "_")) {
                     provinceCityCountryList = (List<Map<String, Object>>) existMap.get(province + "_" + city + "_");
                 } else {
                     provinceCityCountryList = new ArrayList<Map<String, Object>>();
                     existMap.put(province + "_" + city + "_", provinceCityCountryList);
                     provinceCityMap.put("level", provinceCityCountryList);
                 }

                 String country = map.get("country");
                 Map<String, Object> provinceCityCountryMap = null;
                 if (StringUtils.isNotEmpty(country)) {

                         provinceCityCountryMap = new HashMap<String, Object>();
                         provinceCityCountryList.add(provinceCityCountryMap);
                         String countrySort = String.valueOf(existMap.get(province + "_" + city + "_sort"));
                         existMap.put(province + "_" + city + "_sort", "null".equals(countrySort) ? 1 : NumberUtils.toInt(countrySort) + 1);
                         provinceCityCountryMap.put("sort", existMap.get(province + "_" + city + "_sort"));

                     provinceCityCountryMap.put("Code", map.get("countryCode"));
                     provinceCityCountryMap.put("Name", country);
                 } else {
                     provinceCityCountryMap = new HashMap<String, Object>();
                     provinceCityCountryList.add(provinceCityCountryMap);
                     provinceCityCountryMap.put("sort", 1);
                     provinceCityCountryMap.put("Code", "");
                     provinceCityCountryMap.put("Name", "");
                 }
             }
         }

         try {
             return JsonUtils.toJson(zoneList);
         } catch (Exception e) {
             e.printStackTrace();
         }

         return null;
     }
     

5.4

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