MyBatis-Plus元数据拦截器

1.sun-common-mybatisplus 模块创建一个MyMetaObjectHandler.java

import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;

import java.util.Date;

/**
 * Description: 元数据拦截器
 * 注意事项：在插入和更新时，实体类必须具有fieldName这些字段，并且要有getter和setter方法
 * @Author sun
 * @Create 2024/7/10 14:25
 * @Version 1.0
 */
@Component // 注入容器
public class MyMetaObjectHandler implements MetaObjectHandler {

    /**
     * 插入时默认填充的数据
     * @param metaObject
     */
    @Override
    public void insertFill(MetaObject metaObject) {
        this.strictInsertFill(metaObject, "createBy", String.class, "handler/com/sunxiansheng");
        this.strictInsertFill(metaObject, "createTime", Date.class, new Date());
        this.strictInsertFill(metaObject, "deleteFlag", Integer.class, 0);
        this.strictInsertFill(metaObject, "version", Integer.class, 0);
    }

    /**
     * 更新时默认填充的数据
     * @param metaObject
     */
    @Override
    public void updateFill(MetaObject metaObject) {
        this.strictUpdateFill(metaObject, "updateBy", String.class, "handler/com/sunxiansheng");
        this.strictUpdateFill(metaObject, "updateTime", Date.class, new Date());
    }

}

2.注意事项

在插入和更新时，实体类必须具有fieldName这些字段，并且要有getter和setter方法

3.在po字段上添加@TableField注解

package com.sunxiansheng.user.entity.po;

import com.baomidou.mybatisplus.annotation.*;
import lombok.Data;

import java.util.Date;

/**
 * Description: 封装从数据库中查询的数据
 * @Author sun
 * @Create 2024/7/9 16:02
 * @Version 1.0
 */
@TableName("user") // 指定表名
@Data
public class UserPo {

    @TableId(value = "id", type = IdType.AUTO) // 指定主键
    private Long id;

    private String name;

    private Integer age;

    @TableField(fill = FieldFill.INSERT)
    private String createBy;

    @TableField(fill = FieldFill.INSERT)
    private Date createTime;

    @TableField(fill = FieldFill.UPDATE)
    private String updateBy;

    @TableField(fill = FieldFill.UPDATE)
    private Date updateTime;

    @TableField(fill = FieldFill.INSERT)
    private Integer deleteFlag;

    @TableField(fill = FieldFill.INSERT)
    private Integer version;

}

4.测试插入，发现没有自动填充

1.原因是bean没有被注入

2.修改包名为UserApplicaion.java的扫描路径

3.bean成功注入

4.重新测试

5.抽取自动填充的属性作为基类

1.在commom模块编写

2.BaseEntity.java

package com.sunxiansheng.entity;

import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;

import java.io.Serializable;
import java.util.Date;

/**
 * Description: entity的基类，将一些需要自动填充的属性抽取过来
 * @Author sun
 * @Create 2024/7/10 16:28
 * @Version 1.0
 */
@Data
public class BaseEntity implements Serializable {

    @TableField(fill = FieldFill.INSERT)
    private String createBy;

    @TableField(fill = FieldFill.INSERT)
    private Date createTime;

    @TableField(fill = FieldFill.UPDATE)
    private String updateBy;

    @TableField(fill = FieldFill.UPDATE)
    private Date updateTime;

    @TableField(fill = FieldFill.INSERT)
    private Integer deleteFlag;

    @TableField(fill = FieldFill.INSERT)
    private Integer version;

}

3.修改UserPo.java，继承基类