1.使用代码生成器,生成课程分类代码
把我们原先的代码生成器打开,修改一下,然后运行。
运行之后:出现了新生成的文件
2.创建实体类,和excel有对应关系
4.编写service方法
编写监听器代码:
整个监听器代码:
package com.atguigu.eduservice.listener;
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.atguigu.eduservice.entity.EduSubject;
import com.atguigu.eduservice.entity.excel.SubjectData;
import com.atguigu.eduservice.service.EduSubjectService;
import com.atguigu.servicebase.exceptionhandler.GuliException;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
public class SubjectExcelListener extends AnalysisEventListener<SubjectData> {
//因为SubjectExcelListener不能交给spring进行管理,需要自己new,不能注入其他对象,也不能实现数据库操作
public EduSubjectService subjectService;
public SubjectExcelListener() {
}
public SubjectExcelListener(EduSubjectService subjectService) {
this.subjectService = subjectService;
}
//读取excel内容,一行一行进行读取
@Override
public void invoke(SubjectData subjectData, AnalysisContext analysisContext) {
if(subjectData == null){
throw new GuliException(20001,"文件数据为空");
}
//一行一行读取,每次读取有两个值,第一个值是一级分类,第二个值是二级分类
//1.添加一级分类
//判断一级分类是否重复
EduSubject existOneSubject = this.existOneSubject(subjectService,subjectData.getOneSubjectName());
//表中没有相同的一级分类,进行添加
if(existOneSubject == null){
existOneSubject = new EduSubject();
existOneSubject.setParentId("0");
existOneSubject.setTitle(subjectData.getOneSubjectName());
subjectService.save(existOneSubject);
}
//2.添加二级分类
//获取一级分类的id值
String pid = existOneSubject.getId();
//判断二级分类是否重复
EduSubject existTwoSubject = this.existTwoSubject(subjectService,subjectData.getTwoSubjectName(),pid);
if(existTwoSubject == null){
existTwoSubject = new EduSubject();
existTwoSubject.setParentId(pid);
existTwoSubject.setTitle(subjectData.getTwoSubjectName());
subjectService.save(existTwoSubject);
}
}
//判断一级分类不能重复添加
private EduSubject existOneSubject(EduSubjectService subjectService,String name){
QueryWrapper<EduSubject> wrapper = new QueryWrapper<>();
wrapper.eq("title",name);
wrapper.eq("parent_id","0");
EduSubject oneSubject = subjectService.getOne(wrapper);
return oneSubject;
}
//判断二级分类不能重复添加
private EduSubject existTwoSubject(EduSubjectService subjectService,String name,String pid){
QueryWrapper<EduSubject> wrapper = new QueryWrapper<>();
wrapper.eq("title",name);
wrapper.eq("parent_id",pid);
EduSubject twoSubject = subjectService.getOne(wrapper);
return twoSubject;
}
@Override
public void doAfterAllAnalysed(AnalysisContext analysisContext) {
}
}
5.测试