easyexcel导入数据的用法

创建数据库的表，创建实体类，mapper等

public class InvestigateListener extends AnalysisEventListener<InvestigateExcel> {
    private DictMapper dictMapper;
    private InvestigateObjectMapper investigateMapper;

    public InvestigateListener(DictMapper dictMapper, InvestigateObjectMapper investigateMapper) {
        this.dictMapper = dictMapper;
        this.investigateMapper = investigateMapper;
    }

    private int num;

    private List<InvestigateObject> investigateObjectList=new ArrayList<InvestigateObject>();
    public List<ImportError> errorList = new ArrayList<>();
    //一行一行读
    @Override
    public void invoke(InvestigateExcel investigateExcel, AnalysisContext analysisContext) {
        ImportError importError = mustFieldIsNull(investigateExcel);
        //如果没错就将该行加入集合
        if(importError.getErrorMsg()==null&&importError.getParseError()==null&&importError.getTablePosition()==null){
            investigateExcel.setId(null);
            InvestigateObject investigateObject = new InvestigateObject();
            BeanUtil.copyProperties(investigateExcel,investigateObject);
            investigateObjectList.add(investigateObject);
        }else {
            errorList.add(importError);
        }
    }

    /**
     * 全部的数据解析完毕后调用次方法 再次方法可做操作数据库动作 提交容器数据
     */
    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
        num = 0;
        // 将数据导入数据库
        for (int i = 0; i < investigateObjectList.size(); i++) {
           investigateMapper.insert(investigateObjectList.get(i));
        }
    }
    public ImportError mustFieldIsNull(InvestigateExcel demoData) {
        if (objectCheckIsNull(demoData)) return null;//判断最后一行是否为Null
        num++;
        ImportError importError = new ImportError();
        String pro = demoData.getPro();
        String city = demoData.getCity();
        String county = demoData.getCounty();
        Long code = demoData.getCode();
        String town= demoData.getTown();
        if (StringUtils.isBlank(pro)||StringUtils.isBlank(city)||StringUtils.isBlank(county)
        ||Objects.isNull(code)||StringUtils.isBlank(town)) {
            //如果存在空值
            importError.setErrorMsg(" [县区市旗*]列存在空职或其他错误");
            importError.setTablePosition(num + "行");
            return importError;
        }
        QueryWrapper<InvestigateObject> queryWrapper = new QueryWrapper<>();
        InvestigateObject one = investigateMapper.selectOne(queryWrapper.eq("code", demoData.getCode()));
        if(one!=null){
            importError.setErrorMsg(demoData.getCode()+"该编码已存在！！");
            importError.setTablePosition(num+"行");
            return importError;
        }
        QueryWrapper<Dict> wrapper = new QueryWrapper<Dict>();
        Dict  dict= dictMapper.selectOne(wrapper.eq("name", demoData.getPro()).eq("type", "area"));
        if(dict==null){
            importError.setErrorMsg(demoData.getPro()+"数据有问题！！");
            importError.setTablePosition(num+"行");
            return importError;
        }
        QueryWrapper<Dict> wrapper1 = new QueryWrapper<>();
        Dict dict1 = dictMapper.selectOne(wrapper1.eq("name", demoData.getCity()).eq("pid", dict.getValue()));
        if(dict1==null){
            importError.setErrorMsg(demoData.getCity()+"数据有问题！！");
            importError.setTablePosition(num+"行");
            return importError;
        }
        QueryWrapper<Dict> wrapper2 = new QueryWrapper<>();
        Dict dict2 = dictMapper.selectOne(wrapper2.eq("pid", dict1.getValue()).eq("name", demoData.getCounty()));
        if(dict2==null){
            importError.setErrorMsg(demoData.getCounty()+"数据有问题！！");
            importError.setTablePosition(num+"行");
            return importError;
        }
        //TODO 没有全部判断完全
        return importError;
    }
    public static boolean objectCheckIsNull(Object object) {
        boolean flag = true; //定义返回结果，默认为true
        if (Objects.isNull(object)) {
            flag = true;
        } else {
            Class clazz = (Class) object.getClass(); // 得到类对象
            Field fields[] = clazz.getDeclaredFields(); // 得到所有属性
            for (Field field : fields) {
                field.setAccessible(true);
                Object fieldValue = null;
                try {
                    fieldValue = field.get(object); //得到属性值
                    Type fieldType = field.getGenericType();//得到属性类型
                    String fieldName = field.getName(); // 得到属性名
                } catch (IllegalArgumentException e) {
                } catch (IllegalAccessException e) {
                }
                if (fieldValue != null) {  //只要有一个属性值不为null 就返回false 表示对象不为null
                    flag = false;
                    break;
                }
            }
        }
        return flag;
    }
}

 @Override
    @Transactional
    public Result<Object> importInvest(MultipartFile file)  {
        if (
                Objects.requireNonNull(file.getOriginalFilename()).contains(".xlsx") || file.getOriginalFilename().contains(".xls")
        ){
            try {
                InvestigateListener investigateListener= new InvestigateListener(dictMapper,investigateMapper);
                EasyExcel.read(file.getInputStream(), InvestigateExcel.class,investigateListener).sheet().doRead();
                List<ImportError> errors = investigateListener.errorList;
                if(errors.size()>0){
                    return Result.error(errors);
                }else return Result.ok();

            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return Result.error("文件类型错误");
    }