Map使用总结以及使用map将（国家-省-区）进行重新封装传给vue

最新推荐文章于 2023-07-17 13:03:56 发布

原创最新推荐文章于 2023-07-17 13:03:56 发布 · 591 阅读

0 ·

CC 4.0 BY-SA版权

IDEA使用同时被 3 个专栏收录

14 篇文章

订阅专栏

Vue与SpringBoot

12 篇文章

订阅专栏

开发调试工具

7 篇文章

订阅专栏

本文深入探讨了Java中Map的基本应用，包括HashMap的定义、值的获取与List解析，并通过实例展示了如何使用Map封装国家、省、市信息，提供给前端Vue使用。同时，文章还介绍了如何将DISTRICT_ID和DISTRICT_NAME转换为value和label，以便于前端展示。

最近在工作中被map折腾快疯了，工作的同时特别喜欢用HashMap老返回数据，灵活性特别不好。

一、map的基本应用

1、map的定义

Map<String, String> parameters = new HashMap<>();
parameters.put("appKey", "k");
parameters.put("tableName", "order");
parameters.put("primaryKey", orderId);

2、获取map中的值或对象

Object = map.get("detail");

根据不同类型的数据，获取不同的数据，如果返回的是一个object，需要使用object来接。JSONObject dataObject = jsonObject.getJSONObject("data");

Integer errCode = dataObject.getInt("errCode");

3、用for解析List List<Map<String, Object>>for (Map<String, Object> country : countryList)provinceList = settingService.getProvinceInfo(String.valueOf(country.get("DISTRICT_ID")));

country.put("provinceList", provinceList);

二、使用map将（国家-省-区）进行重新封装传给vue

1、获取国家省区的接口代码

@ResponseBody
    @GetMapping("/getSelectAddressInfo")
    public BaseResponse getSelectAddressInfo(HttpServletRequest request) {
        BaseResponse response = BaseResponse.success();
        try {
            String provinceId = request.getParameter("provinceId");
            String cityId = request.getParameter("cityId");
            List<Map<String, Object>> countryList = settingService.getCountyInfo();
            List<Map<String, Object>> provinceList = null;
            List<Map<String, Object>> cityList = null;
            for (Map<String, Object> country : countryList)
            {
                if(StringUtils.isNotEmpty(provinceId)){
                    provinceList = settingService.getProvinceInfo(provinceId);
                    country.put("provinceList", provinceList);
                    for (Map<String, Object> province : provinceList){
                        if(StringUtils.isNotEmpty(cityId)){
                            cityList = settingService.getCityInfo(cityId);
                            province.put("cityList",cityList);
                            break;
                        }else{
                            cityList = settingService.getCityInfo(String.valueOf(province.get("DISTRICT_ID")));
                            province.put("cityList",cityList);
                        }
                    }
                    break;
                }else{
                    provinceList = settingService.getProvinceInfo(String.valueOf(country.get("DISTRICT_ID")));
                    country.put("provinceList", provinceList);
                    for (Map<String, Object> province : provinceList){
                        if(StringUtils.isNotEmpty(cityId)){
                            cityList = settingService.getCityInfo(cityId);
                            province.put("cityList",cityList);
                            break;
                        }else{
                            cityList = settingService.getCityInfo(String.valueOf(province.get("DISTRICT_ID")));
                            province.put("cityList",cityList);
                        }
                    }
                }

            }
            response.setExtData(ImmutableMap.builder().put("countryList", convertFirstDto(countryList,0)).put("showMsg", "国家信息获取成功").build());

        } catch (Exception e) {
            log.error("getProvinceInfo error", e);
            response.setExtData(ImmutableMap.builder().put("showMsg", "国家信息获取失败").build());
        }
        return response;

    }

2、多加一层将DISTRICT_ID和DISTRICT_NAME转为value和label

private List<AddressTreeDto> convertFirstDto(List<Map<String, Object>> list, int level){
        if(list==null){
            return null;
        }
        level++;
        List<AddressTreeDto> dtos=new ArrayList<>();
        for(Map<String, Object> tree:list){
            AddressTreeDto dto=new AddressTreeDto();
            dto.setCode(String.valueOf(tree.get("PHONE_PREFIX")));
            dto.setValue(String.valueOf(tree.get("DISTRICT_ID")));
            dto.setLabel(String.valueOf(tree.get("DISTRICT_NAME")));
            dto.setLevel(level);
            List<Map<String, Object>> resultList = null;
            resultList = (List)tree.get("provinceList");
            if(CollectionUtils.isNotEmpty(resultList)){
                dto.setChildren(convertDto(resultList,level));
            }
            dtos.add(dto);
        }
        return dtos;
    }

private List<AddressTreeDto> convertDto(List<Map<String, Object>> list, int level){
        if(list==null){
            return null;
        }
        level++;
        List<AddressTreeDto> cityDtos=new ArrayList<>();
        for(Map<String, Object> cityTree:list){
            AddressTreeDto citydto=new AddressTreeDto();
            citydto.setValue(String.valueOf(cityTree.get("DISTRICT_ID")));
            citydto.setLabel(String.valueOf(cityTree.get("DISTRICT_NAME")));
            citydto.setLevel(level);
            List<Map<String, Object>> resultList = (List)cityTree.get("cityList");
            if(CollectionUtils.isNotEmpty(resultList)){
                citydto.setChildren(convertDto(resultList,level));
            }
            cityDtos.add(citydto);
        }
        return cityDtos;
    }