package com.hyq.pojo;

import com.baomidou.mybatisplus.annotation.*;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.format.annotation.DateTimeFormat;

import java.util.Date;

@Data
@AllArgsConstructor
@NoArgsConstructor
@TableName("user")
public class User {
    @TableId(type = IdType.AUTO)
    private Long id;
    private String name;
    private Integer age;
    private String email;
    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @TableField(fill = FieldFill.INSERT)  //插入時(shí)更新
    private Date createTime;
    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @TableField(fill = FieldFill.INSERT_UPDATE)   //添加時(shí)更新  之后寫(xiě)策略
    private Date updateTime;


}

@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @TableField(fill = FieldFill.INSERT)  //插入時(shí)更新
    private Date createTime;
    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @TableField(fill = FieldFill.INSERT_UPDATE)   //添加時(shí)更新  之后寫(xiě)策略
    private Date updateTime;

package com.hyq.handler;

import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;

import java.util.Date;

@Slf4j
@Component  //一定不要忘記把處理器加到io容器c中
public class MyMetaObjectHandler implements MetaObjectHandler {

    //插入時(shí)的填充策略
    @Override
    public void insertFill(MetaObject metaObject) {
        log.info("start insert fill......");
        this.setFieldValByName("createTime", new Date(), metaObject);
        this.setFieldValByName("updateTime", new Date(), metaObject);
    }
    //更新時(shí)的填充策略
    @Override
    public void updateFill(MetaObject metaObject) {
        log.info("start insert fill......");
        this.setFieldValByName("updateTime", new Date(), metaObject);

    }
}

    /**
     * 通用填充
     *
     * @param fieldName  java bean property name  字段名稱(chēng)
     * @param fieldVal   java bean property value 屬性值
     * @param metaObject meta object parameter 元對(duì)象參數(shù)
     */
    default MetaObjectHandler setFieldValByName(String fieldName, Object fieldVal, MetaObject metaObject) {
        if (Objects.nonNull(fieldVal) && metaObject.hasSetter(fieldName)) {
            metaObject.setValue(fieldName, fieldVal);
        }
        return this;
    }