判空
对集合判空
//锁定库存
List<Stock> stockList = stockMapper.findStocksForUpdate(productIds);
if(CollectionUtils.isEmpty(stockList)){
throw new BizException("库存未初始化");
}
if(stockList.size() != productIds.size()){
throw new BizException("部分商品库存未初始化!");
}
Json转换成一个类
String jsonObject = JSON.toJSONString(object);
CartProductDto cartProductDto = JSONObject.parseObject(jsonObject, CartProductDto.class);
TK-MYBATIS
查询
Example example = new Example(Member.class);
example.createCriteria().andEqualTo("username",request.getUserName());
List<Member> memberList = memberMapper.selectByExample(example);
token
String userInfo = (String) request.getAttribute(TokenIntercepter.USER_INFO_KEY);
JSONObject jsonObject = JSON.parseObject(userInfo);
String username = (String) jsonObject.get("username");
Integer id = (Integer) jsonObject.get("uid");
Long uid = Long.valueOf(id);
json查看接口文档
