Structuring Session‑Based Scene Data with MyBatis in Java

In a typical business scenario a single sessionId can correspond to multiple sceneId / sceneName pairs, but the original JSON returned a List<SceneVO> where each element duplicated the same sessionId.

To make the data structure clearer for the front‑end, the sessionId is extracted to the outer level and the scenes are placed inside a sceneList array.

{
  "data": {
    "sessionId": "jksadhjksd",
    "sceneList": [
      {"sceneId":"NDJWKSDSJKDKED","sceneName":"场景1"},
      {"sceneId":"KLJSDJKLSDFALK","sceneName":"场景2"},
      {"sceneId":"KERFJKOVDJKDSS","sceneName":"场景3"}
    ]
  }
}

The Java entity classes are defined as follows:

public class SceneVO {
    private String sessionId;
    private List<SubSceneVO> sceneList;
    // getters and setters omitted
}

public class SubSceneVO {
    private String sceneId;
    private String sceneName;
    // getters and setters omitted
}

A custom MyBatis mapper interface and its XML mapping handle the one‑to‑many relationship:

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="your.package.mapper.BusinessScenesCustomMapper">
    <resultMap id="BaseResultMap" type="your.package.vo.SceneVO">
        <result column="session_id" jdbcType="VARCHAR" property="sessionId"/>
        <!-- collection defines the List<SubSceneVO> mapping -->
        <collection property="sceneList" ofType="your.package.vo.SubSceneVO">
            <result column="scene_id" jdbcType="VARCHAR" property="sceneId"/>
            <result column="scene_name" jdbcType="VARCHAR" property="sceneName"/>
        </collection>
    </resultMap>
    <select id="selectBySessionId" parameterType="string" resultMap="BaseResultMap">
        SELECT session_id, scene_id, scene_name
        FROM your_table
        WHERE session_id = #{sessionId,jdbcType=VARCHAR}
    </select>
</mapper>

The service layer simply delegates to the mapper:

public interface SceneService {
    /** Get scene information for a given session */
    SceneVO getScenesInfo(String sessionId);
}

@Service
public class SceneServiceImpl implements SceneService {
    @Resource
    private BusinessScenesCustomMapper businessScenesCustomMapper;

    @Override
    public SceneVO getScenesInfo(String sessionId) {
        return businessScenesCustomMapper.selectBySessionId(sessionId);
    }
}

Finally, a REST controller exposes the data through an endpoint:

@RestController
public class SceneController {
    @Resource
    private SceneService sceneService;

    @GetMapping("/getScenesInfo")
    public ResModel getScenesInfo(String sessionId) {
        SceneVO sceneVO = sceneService.getScenesInfo(sessionId);
        return ResModel.ok(sceneVO);
    }
}