文章目录
- 1.业务背景
- 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?
- 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<SubSceneVO> 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);
}
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="你的包名.mapper.BusinessScenesCustomMapper"><resultMap id="BaseResultMap" type="你的包名.vo.SceneVO"><result column="session_id" jdbcType="VARCHAR" property="sessionId"/><!--collection 标签:用于定义关联的list集合类型的封装规则property:对应父类中list属性名,这里SceneVO类里的List变量名为sceneListofType:集合存放的类型,List集合要装的类的类名,这里是SubSceneVO--><collection property="sceneList" ofType="你的包名.vo.SubSceneVO"><result column="scene_id" jdbcType="VARCHAR" property="sceneId"/><result column="scene_name" jdbcType="VARCHAR" property="sceneName"/></collection></resultMap><!-- 一个session_id对应多条记录,返回的是SceneVO对象,SceneVO对象有一个List装着SubSceneVO --><select id="selectBySessionId" parameterType="string" resultMap="BaseResultMap">select session_id, scene_id, scene_namefrom 表名where session_id = #{sessionId,jdbcType=VARCHAR}</select>
- 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 {@Resourceprivate 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);
}