Mybatis-plus读取JSON类型

Mybatis-plus读取JSON类型

版本：

<dependency>
      <groupId>com.baomidou</groupId>
      <artifactId>mybatis-plus-boot-starter</artifactId>
      <version>3.3.1.tmp</version>
    </dependency>

一、Mybatis基本查询

共三个步骤：

1、在数据库表定义JSON字段；
2、在实体类加上@TableName(autoResultMap = true)、在JSON字段映射的属性加上@TableField(typeHandler = FastjsonTypeHandler.class)；
3、建一些业务代码进行测试；

• 在数据库表定义JSON字段

CREATE TABLE `extra_info`  (
   `id` int(10) NOT NULL AUTO_INCREMENT PRIMARY KEY,
   `extra_object` json NULL,
   `extra_list` json NULL,
   `extra_array` json NULL
 );

INSERT INTO `extra_info` VALUES (1, '{\"id\": 1, \"name\": \"2\"}', '[{\"id\": 1, \"name\": \"2\"}]', '[{\"id\": 1, \"name\": \"2\"}]');

• 在实体类加上@TableName(autoResultMap = true)、在JSON字段映射的属性加上@TableField(typeHandler = FastjsonTypeHandler.class)

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.extension.handlers.FastjsonTypeHandler;

import java.io.Serializable;
import java.util.List;

@TableName(autoResultMap = true)
public class ExtraInfo implements Serializable {

    @TableId(type = IdType.AUTO)
    private Integer id;

    @TableField(typeHandler = FastjsonTypeHandler.class)
    private ExtraNode extraObject;

    @TableField(typeHandler = FastjsonTypeHandler.class)
    private List<ExtraNode> extraList;

    @TableField(typeHandler = FastjsonTypeHandler.class)
    private ExtraNode[] extraArray;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public ExtraNode getExtraObject() {
        return extraObject;
    }

    public void setExtraObject(ExtraNode extraObject) {
        this.extraObject = extraObject;
    }

    public List<ExtraNode> getExtraList() {
        return extraList;
    }

    public void setExtraList(List<ExtraNode> extraList) {
        this.extraList = extraList;
    }

    public ExtraNode[] getExtraArray() {
        return extraArray;
    }

    public void setExtraArray(ExtraNode[] extraArray) {
        this.extraArray = extraArray;
    }
}

• 建一些业务代码进行测试

import java.io.Serializable;

public class ExtraNode implements Serializable {

    private Integer id;
    private String name;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.springframework.stereotype.Repository;

@Repository
public interface ExtraInfoMapper extends BaseMapper<ExtraInfo> {
}
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/test")
public class TestController {

    @Autowired
    private ExtraInfoMapper extraInfoMapper;

    @GetMapping
    public List<ExtraInfo> listAll() {
        return this.extraInfoMapper.selectList(new LambdaQueryWrapper<>());
    }
}
运行结果：

[
  {
    "id": 1,
    "extraObject": { "id": 1, "name": "2" },
    "extraList": [
      { "name": "2", "id": 1 }
    ],
    "extraArray": [
      { "id": 1, "name": "2" }
    ]
  }
]

二、nataive自义SQL查询

1、在实体类加上@TableName(autoResultMap = true)、在JSON字段映射的属性加上@TableField(typeHandler = FastjsonTypeHandler.class)；

2、XXMapper.xml里json型字段到类的映射

<resultMap>
     <result property="jsonDataField" column="json_data_field" jdbcType="OTHER" javaType="com.alibaba.fastjson.JSONObject" typeHandler="com.baomidou.mybatisplus.extension.handlers.FastjsonTypeHandler"/>
</resultMap>

实体类

package cc.oyz.bean;

import com.alibaba.fastjson.JSONObject;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.extension.handlers.FastjsonTypeHandler;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

/**
 * @description: 辖区管理
 * @author: libin.hao
 * @time: 2021/4/8 15:35
 */
@Data
@TableName(autoResultMap = true)
public class UrbanArea {

    @TableId(value = "id",type = IdType.AUTO)
    @ApiModelProperty(value = "主键ID",example="主键ID")
    private Integer id;

    private String name;

    private Double height;

    @ApiModelProperty(value = "地理数据")
    private String geog;

    @ApiModelProperty(value = "几何数据")
    private String geometry;

    @TableField(typeHandler = FastjsonTypeHandler.class)
    private JSONObject destination;

    @TableField(typeHandler = FastjsonTypeHandler.class)
    private JSONObject orientation;

}

Mapper.xml文件

<?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="cc.oyz.mapper.UrbanAreaMapper" >

    <resultMap id="BaseResultMap" type="cc.oyz.bean.UrbanArea" >
        <id column="id" property="id" jdbcType="INTEGER" />
        <result column="name" property="name" jdbcType="VARCHAR" />
        <result column="height" property="height" jdbcType="DOUBLE" />
        <result column="geog" property="geog" jdbcType="VARCHAR" />
        <result column="geometry" property="geometry" jdbcType="VARCHAR" />
        <result column="destination" property="destination" jdbcType="OTHER" javaType="com.alibaba.fastjson.JSONObject" typeHandler="com.baomidou.mybatisplus.extension.handlers.FastjsonTypeHandler" />
        <result column="orientation" property="orientation" jdbcType="OTHER" javaType="com.alibaba.fastjson.JSONObject" typeHandler="com.baomidou.mybatisplus.extension.handlers.FastjsonTypeHandler" />
    </resultMap>

    <select id="selectOneByName" resultType="cc.oyz.bean.UrbanArea" resultMap="BaseResultMap">
        SELECT
            *,
            ST_AsGeoJson ( geog ) AS geometry
        FROM
            urban_area
        WHERE 1 = 1
        <if test="name != null and name != ''">
            AND name = #{name}
        </if>
    </select>

</mapper>