day99-缓存-缓存使用-改造三级分类业务

1.三级分类业务代码改造

将原本一个方法改为俩方法,代码如下

    @Override
    public Map<String, List<Catelog2Vo>> getCatalogJson(){
        //先从缓存中尝试获取，若为空则从数据库中获取然后放入缓存
        ValueOperations<String, String> opsForValue = stringRedisTemplate.opsForValue();
        String catalogJson = opsForValue.get("catalogJson");
        if(StringUtils.isEmpty(catalogJson)){
            Map<String, List<Catelog2Vo>> catalogJsonFromDb = getCatalogJsonFromDb();
            String str = JSON.toJSONString(catalogJsonFromDb);
            opsForValue.set("catalogJson",str);
            return  catalogJsonFromDb;
        }

        Map<String, List<Catelog2Vo>> catalogJsonFromCache = JSON.parseObject(catalogJson, new TypeReference<Map<String, List<Catelog2Vo>>>(){});
        return catalogJsonFromCache;
    }

    public Map<String, List<Catelog2Vo>> getCatalogJsonFromDb() {

        List<CategoryEntity> categoryEntities = this.list(null);

        List<CategoryEntity> category1EntityList = getParent_cid(categoryEntities,0l);

        Map<String, List<Catelog2Vo>> catelog2Vos = category1EntityList.stream().collect(Collectors.toMap(k -> k.getCatId().toString(), v -> {
            //1.查到一级分类的所有二级分类
            List<CategoryEntity> category2EntityList = getParent_cid(categoryEntities,v.getCatId());

            //2.获取二级分类vo集合  用户
            List<Catelog2Vo> catelog2VoList = category2EntityList.stream().map(catelog2 -> {

                List<CategoryEntity> category3EntityList = getParent_cid(categoryEntities,catelog2.getCatId());

                //3.获取三级分类vo集合
                List<Catelog2Vo.Catelog3Vo> catelog3Vos = null;
                if(category3EntityList !=null && category3EntityList.size() > 0){
                    catelog3Vos = category3EntityList.stream().map(catelog3 -> {
                        //获取三级分类vo
                        Catelog2Vo.Catelog3Vo catelog3Vo = new Catelog2Vo.Catelog3Vo(catelog3.getParentCid().toString(), catelog3.getCatId().toString(), catelog3.getName());
                        return catelog3Vo;
                    }).collect(Collectors.toList());
                }
                //2.获取二级分类vo
                Catelog2Vo catelog2Vo = new Catelog2Vo(v.getCatId().toString(), catelog3Vos, catelog2.getCatId().toString(), catelog2.getName());

                return catelog2Vo;
            }).collect(Collectors.toList());
            return catelog2VoList;
        }));

        return catelog2Vos;
    }

2.测试

浏览器请求，第一次慢一点，后面都很快,很明显数据进了缓存

缓存中也能查看到