mybatis-plus读取JSON类型的方法实现

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" }
    ]
  }
]