做easyexcel遇到的问题数据库采用的mybatis-plus

导入坐标

<!-- easyexcel依赖-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>easyexcel</artifactId>
    <version>2.1.1</version>
</dependency>

service层

//添加课程分类
    @Override
    public void saveSubject(MultipartFile file, EduSubjectService subjectService) {

        try {
            InputStream in = file.getInputStream();
            EasyExcel.read(in, SubjectData.class, new SubjectListener(subjectService)).sheet().doRead();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

监听器里面要注意：

//因为SubjectListener不能交给Spring管理，需要自己new，不能注入其他对象
//不能实现数据库的操作,利用有参构造传过来

public class SubjectListener extends AnalysisEventListener<SubjectData> {

    //因为SubjectListener不能交给Spring管理，需要自己new，不能注入其他对象
    //不能实现数据库的操作,利用有参构造传过来

    public EduSubjectService subjectService;

    public SubjectListener() {
    }

    public SubjectListener(EduSubjectService subjectService) {
        this.subjectService = subjectService;
    }

    //读取excel内容，一行一行的读取
    @Override
    public void invoke(SubjectData subjectData, AnalysisContext analysisContext) {

        if (subjectData == null){
            throw new GuliException(20001,"文件数据为空");
        }
        EduSubject existOneSubject = this.existOneSubject(subjectData.getOneSubjectName(), subjectService);

        if (existOneSubject==null){//表里没有相同的一级分类，进行添加
            EduSubject subject = new EduSubject();
            subject.setParentId("0");
            subject.setTitle(subjectData.getOneSubjectName());//一级分类名称
            subjectService.save(subject);
        }

        //获取一级分类的id值
        String pid=existOneSubject.getId();
        //添加二级分类
        //判断二级分类是否重复

        EduSubject existTwoSubject = this.existTwoSubject(subjectData.getTwoSubjectName(), subjectService, pid);

        if (existTwoSubject == null) {
            EduSubject subject = new EduSubject();
            subject.setParentId(pid);
            subject.setTitle(subjectData.getTwoSubjectName());//二级分类名称
            subjectService.save(subject);
        }
    }

    //判断一级分类不能重复添加
    private EduSubject existOneSubject(String name,EduSubjectService subjectService){
        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(String name,EduSubjectService subjectService,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) {

    }
}

控制层的

subjectService是注入进来的，若用mybatis也需将dao层注入

   public R addSubject(MultipartFile file){
        //上传过来的excel文件
        subjectService.saveSubject(file,subjectService);
        return R.ok();
    }