mybatis-plus读取JSON类型

摘要：mybatis-plus读取JSON类型。

本文总共三个步骤：
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" }
    ]
  }
]