博客

Mybatis-plus实现字段自动填充

package com.fn.config;

import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import com.fn.common.core.service.TokenService;
import com.fn.entity.Article;
import com.fn.entity.Knowledge;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;

/**
 * Description: 描述
 * author: MrLee
 * date:   2021/8/18 11:47
 */
@Component
public class MyMetaObjectHandler implements MetaObjectHandler {

    @Autowired
    private TokenService tokenService;

    /**
     * 排除自动填充的实体
     */
    public static List<String> excludeClasses = new ArrayList<>();

    static {
        //文章
        excludeClasses.add("com.fn.entity.Article");
        //知识
        excludeClasses.add("com.fn.entity.Knowledge");

    }

    public boolean isExclude(MetaObject metaObject){
        if(excludeClasses != null && excludeClasses.size() > 0){
            Object originalObject = metaObject.getOriginalObject();
            for(String cls : excludeClasses){
                try {
                    Class<?> clazz = Class.forName(cls);
                    if(originalObject.getClass().isInstance(clazz.newInstance())){
                        return true;
                    }
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
                    e.printStackTrace();
                }
            }
        }
        return false;
    }

    /**
     * 插入时的填充策略
     * @param metaObject
     */
    @Override
    public void insertFill(MetaObject metaObject) {
        if (isExclude(metaObject)) {
            return;
        }
        this.setFieldValByName("createTime", LocalDateTime.now(), metaObject);
        if(tokenService.getLoginUser() != null){
            this.setFieldValByName("createUser", tokenService.getUserId(), metaObject);
        }
    }

    /**
     * 更新时的填充策略
     * @param metaObject
     */
    @Override
    public void updateFill(MetaObject metaObject) {
        if (isExclude(metaObject)) {
            return;
        }
        this.setFieldValByName("updateTime", LocalDateTime.now(), metaObject);
        if(tokenService.getLoginUser() != null){
            this.setFieldValByName("updateUser", tokenService.getUserId(), metaObject);//当前登录人
        }
    }
}