当返回前端的数据中存在List对象集合,如何优雅操作? | 您所在的位置:网站首页 › 怎么遍历集合的数据表 › 当返回前端的数据中存在List对象集合,如何优雅操作? |
文章目录
1.业务背景2.实体类3.自定义Mapper和xml文件4.Service层5.Controller层
1.业务背景
业务场景中,一个会话中存在多个场景,即一个session_id对应多个scene_id和scene_name 如果你写成如下的聚合模型类 public class SceneVO { private String sessionId; private String sceneId; private String sceneName; // 省略对应的getter和setter方法 }返回的List形式如下,这个数据在data属性中 { "data":[ { "sessionId": "jksadhjksd", "sceneId":"NDJWKSDSJKDKED", "sceneName":"场景1" }, { "sessionId": "jksadhjksd", "sceneId":"KLJSDJKLSDFALK", "sceneName":"场景2" }, { "sessionId": "jksadhjksd", "sceneId":"KERFJKOVDJKDSS", "sceneName":"场景3" } ] }每个对象里面都带上了重复的一个sessionId数据,我想提出来该怎么办? 我想改为如下形式,sessionId提出到外层,更能体现出一个sessionId对应多个sceneId和sceneName的含义,这样也便于前端取数据,不然每个对象都要增加一个sessionId属性,太麻烦。 { "data": { "sessionId": "jksadhjksd", "sceneList": [ { "sceneId":"NDJWKSDSJKDKED", "sceneName":"场景1" }, { "sceneId":"KLJSDJKLSDFALK", "sceneName":"场景2" }, { "sceneId":"KERFJKOVDJKDSS", "sceneName":"场景3" } ] } } 2.实体类方法如下: 首先创建两个实体类 public class SceneVO { private String sessionId; private List sceneList; // 省略对应的getter和setter方法 } public class SubSceneVO { private String sceneId; private String sceneName; // 省略对应的getter和setter方法 } 3.自定义Mapper和xml文件 public interface BusinessScenesCustomMapper { SceneVO selectBySessionId(String sessionId); } select session_id, scene_id, scene_name from 表名 where session_id = #{sessionId,jdbcType=VARCHAR}collection标签:用于定义关联的List集合类型的封装规则 property属性:对应父类中List集合的变量名,这里SceneVO类里的List变量名为sceneList ofType属性:集合存放的类型,List集合要装的类的类名,这里是SubSceneVO 4.Service层 public interface SceneService { /** * 获取场景信息 */ SceneVO getScenesInfo(String sessionId); } @Service public class SceneServiceImpl { @Resource private BusinessScenesCustomMapper businessScenesCustomMapper; ...... public SceneVO getScenesInfo(String sessionId) { return businessScenesCustomMapper.selectBySessionId(sessionId); } } 5.Controller层 ...... @Resource private SceneService sceneService; @GetMapping("/getScenesInfo") public ResModel getScenesInfo(String sessionId) { SceneVO sceneVO = sceneService.getScenesInfo(sessionId); return ResModel.ok(sceneVO); } 欢迎一键三连~ 有问题请留言,大家一起探讨学习 ----------------------Talk is cheap, show me the code----------------------- |
CopyRight 2018-2019 实验室设备网 版权所有 |