https://www.heckjj.com/index.php zh-cn https://www.heckjj.com/post// Heck <@hecks.tk> Wed, 08 Mar 2023 03:17:41 +0000 https://www.heckjj.com/post//
Map map = jsonObject.getInnerMap();
List<RecommendDTO> recommendDTOlist = (List<RecommendDTO>) map.get("xxx");

2、进行forearch循环的时候报错

recommendDTOlist .forEach((item)->{})

3、从redis中获取数据后进行遍历
List<RecommendDTO> recommendDTOlist = redisUtil.get(defaultCacheKey);
for (RecommendDTO recommendDTO : defaultRecommendList) {

}

报错信息：

java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to com.heckjj.apps.modules.smartpush.dto.RecommendDTO

4、打断点调试查看发现里面封装的是两个Map 而不是实体类而是个LinkedHashMap

5、解决方法

ObjectMapper mapper = new ObjectMapper();
List<RecommendDTO> recommendDTOlist = (List<RecommendDTO>) map.get("xxx");
List<RecommendDTO> recommendDTOlist = mapper.convertValue(list1, new TypeReference<List<RecommendDTO>>() { });

记住引入包路径是下面这两个

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper; ]]> https://www.heckjj.com/post//#blogcomment <user@domain.com> Thu, 01 Jan 1970 00:00:00 +0000 https://www.heckjj.com/post//#blogcomment