Mybatis返回一个Map中包含多个List问题

发表于

数据

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@Data
public class First {
    private String id;
    private String firstName;
    private List<Second> secondList;
}
@Data
public class Second {
    private String secondId;
    private String secondName;
    private List<Third> thirdList;
}
@Data
public class Third {
    private String thirdId;
    private String thirdName;
}

目的

返回一个List<First>

DAO层

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List<First> selectAllLevel();

Mapper层

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<mapper namespace="com.ymt.zyj.threelevellinkage.dao.LevelLinkageMapper">
    <select id="selectAllLevel" resultMap="OrderMap">
        SELECT f.id,f.firstname,s.secondid,s.secondname,t.thirdid,t.thirdname
        from t_first f,
             t_second s,
             t_third t
        WHERE f.id = s.firstId
          AND s.id = t.secondId
    </select>
	<!--将数据库的字段和entity字段一一匹配-->
    <resultMap type="com.ymt.zyj.threelevellinkage.entity.First" id="OrderMap">
        <id column="id" jdbcType="INTEGER" property="id"/>
        <result column="firstName" jdbcType="VARCHAR" property="firstName"/>
        <collection property="secondList" ofType="com.ymt.zyj.threelevellinkage.entity.Second"
                    javaType="java.util.List">
            <result column="secondId" jdbcType="INTEGER" property="secondId"/>
            <result column="secondName" jdbcType="INTEGER" property="secondName"/>
            <collection property="thirdList" ofType="com.ymt.zyj.threelevellinkage.entity.Third"
                        javaType="java.util.List">
                <result column="thirdId" jdbcType="INTEGER" property="thirdId"/>
                <result column="thirdName" jdbcType="INTEGER" property="thirdName"/>
            </collection>
        </collection>
    </resultMap>
</mapper>

返回信息

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[
  {
    "id": "1",
    "firstName": "户外玩具",
    "secondList": [
      {
        "secondId": "1",
        "secondName": "自行车",
        "thirdList": [
          {
            "thirdId": "1",
            "thirdName": "自行车轮胎"
          },
          {
            "thirdId": "2",
            "thirdName": "自行车把手"
          }
        ]
      },
      {
        "secondId": "2",
        "secondName": "摩托车",
        "thirdList": [
          {
            "thirdId": "3",
            "thirdName": "摩托车轮胎"
          },
          {
            "thirdId": "4",
            "thirdName": "摩托车把手"
          }
        ]
      }
    ]
  },
  {
    "id": "2",
    "firstName": "室内玩具",
    "secondList": [
      {
        "secondId": "3",
        "secondName": "洋娃娃",
        "thirdList": [
          {
            "thirdId": "5",
            "thirdName": "洋娃娃衣服"
          },
          {
            "thirdId": "6",
            "thirdName": "洋娃娃裤子"
          }
        ]
      },
      {
        "secondId": "4",
        "secondName": "毛绒熊",
        "thirdList": [
          {
            "thirdId": "7",
            "thirdName": "毛绒熊衣服"
          },
          {
            "thirdId": "8",
            "thirdName": "毛绒熊裤子"
          }
        ]
      }
    ]
  },
  {
    "id": "3",
    "firstName": "教材教具",
    "secondList": [
      {
        "secondId": "5",
        "secondName": "语文书",
        "thirdList": [
          {
            "thirdId": "9",
            "thirdName": "作文教材"
          },
          {
            "thirdId": "10",
            "thirdName": "文言文教材"
          }
        ]
      },
      {
        "secondId": "6",
        "secondName": "英语书",
        "thirdList": [
          {
            "thirdId": "11",
            "thirdName": "英语听力"
          },
          {
            "thirdId": "12",
            "thirdName": "英语阅读"
          }
        ]
      }
    ]
  }
]
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