一级类目导航代码片段

1第一种写法

//定义一级分类 id -> 二级分类列表
Map<String,List<CatResponseVO>> catResponseVOListMap = new HashMap<>();
//循环分类关联信息
for (IndexCatPO indexCatPO : indexCatPOList) {
    CatResponseVO catResponseVO = new CatResponseVO();
    if (catPOMap.containsKey(indexCatPO.getSlaveCatId())){
        CatPO catPO = catPOMap.get(indexCatPO.getSlaveCatId());
        catResponseVO.setCatName(catPO.getCatName());
        catResponseVO.setCatCode(catPO.getCatCode());
    }
    List<CatResponseVO> catResponseVOList = new ArrayList<>();
    //判断是否存在父级id
    if (catResponseVOListMap.containsKey(indexCatPO.getMasterCatId())){
        catResponseVOList = catResponseVOListMap.get(indexCatPO.getMasterCatId());
    }
    //判断二级分类信息是否为空
    if(!ObjectUtils.isEmpty(catResponseVO)){
        catResponseVOList.add(catResponseVO);
    }
    
    catResponseVOListMap.put(indexCatPO.getMasterCatId(),catResponseVOList);
}

//遍历一级分类

for (CatPO typePO : typePOList) {
    NavigationResponseVO typeResponseVO = new NavigationResponseVO();
    typeResponseVO.setTypeCode(typePO.getCatCode());
    typeResponseVO.setTypeName(typePO.getCatName());
    if (targetIdImage.containsKey(typePO.getId())){
        //取一张图片
        typeResponseVO.setImagePath(targetIdImage.get(typePO.getId()).get(0));
    }else {
        typeResponseVO.setImagePath("");
    }
    if (catResponseVOListMap.containsKey(typePO.getId())){
        typeResponseVO.setCatList(catResponseVOListMap.getOrDefault(typePO.getId(),new ArrayList<>()));
    }
    navigationResponseVOList.add(typeResponseVO);
}

2.第二种写法

//获取一级类目id->二级类目id列表
Map<String, List<String>> slaveCatIdMap = indexCatPOList.stream().collect(Collectors.groupingBy(IndexCatPO::getMasterCatId, Collectors.mapping(IndexCatPO::getSlaveCatId, Collectors.toList())));
//封装数据
for (CatPO typePO : typePOList) {
    NavigationResponseVO typeResponseVO = new NavigationResponseVO();
    typeResponseVO.setTypeCode(typePO.getCatCode());
    typeResponseVO.setTypeName(typePO.getCatName());
    if (targetIdImage.containsKey(typePO.getId())){
        //取一张图片
        typeResponseVO.setImagePath(targetIdImage.get(typePO.getId()).get(0));
    }else {
        typeResponseVO.setImagePath("");
    }
    List<CatResponseVO> catList = new ArrayList<>();
    if (CollectionUtils.isNotEmpty(catList)){
        catList.clear();
    }
    if (slaveCatIdMap.containsKey(typePO.getId())){
        List<String> slaveCatIdList = slaveCatIdMap.get(typePO.getId());
        for (String catId : slaveCatIdList) {
            if (catPOMap.containsKey(catId)){
                CatPO catPO = catPOMap.get(catId);
                CatResponseVO catResponseVO = new CatResponseVO();
                catResponseVO.setCatCode(catPO.getCatCode());
                catResponseVO.setCatName(catPO.getCatName());
                catList.add(catResponseVO);
            }
        }
    }
    typeResponseVO.setCatList(catList);
    navigationResponseVOList.add(typeResponseVO);
}