@ApiOperation(value = "添加商品到购物车", notes = "添加商品到购物车", httpMethod = "POST")
@PostMapping("/add")
public JSONResult add(
@RequestParam String userId,
@RequestBody ShopcartBO shopcartBO,
HttpServletRequest request,
HttpServletResponse response
) {
if (StringUtils.isBlank(userId)) {
return JSONResult.errorMsg("");
}
System.out.println(shopcartBO);
// 前端用户在登录的情况下，添加商品到购物车，会同时在后端同步购物车到redis缓存
// 需要判断当前购物车中包含已经存在的商品，如果存在则累加购买数量
String shopcartJson = redisOperator.get(FOODIE_SHOPCART + ":" + userId);
List<ShopcartBO> shopcartList = null;
if (StringUtils.isNotBlank(shopcartJson)) {
// redis中已经有购物车了
shopcartList = JsonUtils.jsonToList(shopcartJson, ShopcartBO.class);
// 判断购物车中是否存在已有商品，如果有的话counts累加
boolean isHaving = false;
for (ShopcartBO sc: shopcartList) {
String tmpSpecId = sc.getSpecId();
if (tmpSpecId.equals(shopcartBO.getSpecId())) {
sc.setBuyCounts(sc.getBuyCounts() + shopcartBO.getBuyCounts());
isHaving = true;
}
}
if (!isHaving) {
shopcartList.add(shopcartBO);
}
} else {
// redis中没有购物车
shopcartList = new ArrayList<>();
// 直接添加到购物车中
shopcartList.add(shopcartBO);
}
// 覆盖现有redis中的购物车
redisOperator.set(FOODIE_SHOPCART + ":" + userId, JsonUtils.objectToJson(shopcartList));
return JSONResult.ok();
}
public static final String FOODIE_SHOPCART = "shopcart";
@ApiOperation(value = "获取商品子分类", notes = "获取商品子分类", httpMethod = "GET")
@GetMapping("/subCat/{rootCatId}")
public JSONResult subCat(
@ApiParam(name = "rootCatId", value = "一级分类id", required = true)
@PathVariable Integer rootCatId) {
if (rootCatId == null) {
return JSONResult.errorMsg("分类不存在");
}
List<CategoryVO> list = new ArrayList<>();
String catsStr = redisOperator.get("subCat:" + rootCatId);
if (StringUtils.isBlank(catsStr)) {
list = categoryService.getSubCatList(rootCatId);
/**
* 查询的key在redis中不存在，
* 对应的id在数据库也不存在，
* 此时被非法用户进行攻击，大量的请求会直接打在db上，
* 造成宕机，从而影响整个系统，
* 这种现象称之为缓存穿透。
* 解决方案：把空的数据也缓存起来，比如空字符串，空对象，空数组或list
*/
if (list != null && list.size() > 0) {
redisOperator.set("subCat:" + rootCatId, JsonUtils.objectToJson(list));
} else {
redisOperator.set("subCat:" + rootCatId, JsonUtils.objectToJson(list), 5*60);
}
} else {
list = JsonUtils.jsonToList(catsStr, CategoryVO.class);
}
// List<CategoryVO> list = categoryService.getSubCatList(rootCatId);
return JSONResult.ok(list);
}
