Mybatis读取和存储json类型数据的实现

<?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="com.gzl.cn.mysqljson.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="com.gzl.cn.mysqljson.model.User">
        <id column="id" jdbcType="BIGINT" property="id" />
        <result column="name" jdbcType="VARCHAR" property="name" />
        <result column="age" jdbcType="INTEGER" property="age" />
        <result column="email" jdbcType="VARCHAR" property="email" />
        <result column="result_json" jdbcType="OTHER" property="resultJson" javaType="cn.hutool.json.JSONObject" typeHandler="com.baomidou.mybatisplus.extension.handlers.JacksonTypeHandler"/>
        <result column="result_text" jdbcType="VARCHAR" property="resultText" javaType="cn.hutool.json.JSONObject" typeHandler="com.baomidou.mybatisplus.extension.handlers.JacksonTypeHandler"/>
    </resultMap>
    <select id="getAllList" resultMap="BaseResultMap">
        select * from user
    </select>
</mapper>

import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JsonTypeHandler<T> extends BaseTypeHandler<T> {
    private static final ObjectMapper mapper = new ObjectMapper();
    private Class<T> clazz;
    public JsonTypeHandler(Class<T> clazz) {
        if (clazz == null) throw new IllegalArgumentException("Type argument cannot be null");
        this.clazz = clazz;
    }
    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, T parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, this.toJson(parameter));
    }
    @Override
    public T getNullableResult(ResultSet rs, String columnName) throws SQLException {
        return this.toObject(rs.getString(columnName), clazz);
    }
    @Override
    public T getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        return this.toObject(rs.getString(columnIndex), clazz);
    }
    @Override
    public T getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        return this.toObject(cs.getString(columnIndex), clazz);
    }
    private String toJson(T object) {
        try {
            return mapper.writeValueAsString(object);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    private T toObject(String content, Class<?> clazz) {
        if (content != null && !content.isEmpty()) {
            try {
            	// 核心转换，将数据库读取的字符串，转换为指定的class类型
                return (T) mapper.readValue(content, clazz);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        } else {
            return null;
        }
    }
}