fastExcelUtil

@Data
public class FastExcelUtils<T, R, E> {

    private Class<R> resultType;

    private Class<E> excelType;

    private Function<R, E> resultDtoToExcelDtoConvertor;

    private static final int MAX_LOOP_TIMES = 10000;

    private static final WebQHLogger LOG = WebQHLogger.getLogger(FastExcelUtils.class);

    public void exportData(
            @NotNull final HttpServletResponse response,
            final String fileName,
            @NotNull T queryParam,
            @NotNull Function<T, ListResult<R>> query,
            @NotNull Consumer<T> updateQueryParam) throws BizzException {
        setResponseHeader(response, fileName);
        LOG.info("开始导出数据");
        int loop = 0;
        try (ExcelWriter writer = FastExcel
                .write(response.getOutputStream())
                .head(excelType)
                .autoCloseStream(true)
                .build()) {
            final WriteSheet sheet = FastExcel.writerSheet().build();
            ListResult<R> listResult;
            do {
                listResult = query.apply(queryParam);
                if (listResult == null) {
                    throw new BizzException("导出数据失败，返回为null");
                }
                final List<E> excelDtos = resultDtoToExcelDto(listResult.getResult());
                writer.write(excelDtos, sheet);
                updateQueryParam.accept(queryParam);
            } while (BooleanUtils.isTrue(listResult.getHasMore()) && ++loop < MAX_LOOP_TIMES);
        } catch (BizzException e) {
            LOG.warn("导出数据异常", e);
            throw e;
        } catch (Exception e) {
            LOG.error("导出数据异常", e);
            throw new BizzException("导出数据失败");
        }

        if (loop >= MAX_LOOP_TIMES) {
            LOG.warn("导出数据异常，循环次数超过限制");
            throw new BizzException("导出数据异常，超出循环次数");
        }
        LOG.info("导出数据结束");
    }

    private void setResponseHeader(HttpServletResponse response, final String fileName) {
        String exportFileName = StringUtils.defaultIfBlank(fileName, "export");
        exportFileName = StringUtils.endsWithIgnoreCase(exportFileName, ".xlsx") ?
                exportFileName : (exportFileName + ".xlsx");
        try {
            exportFileName = URLEncoder.encode(exportFileName, StandardCharsets.UTF_8.toString());
        } catch (UnsupportedEncodingException e) {
            LOG.warn("URLEncoder.encode fail", e);
        }
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        response.setHeader("Content-disposition", "attachment;filename=" + exportFileName);
        response.setCharacterEncoding("utf8");
        response.setHeader("Cache-Control", "no-store");
        response.addHeader("Cache-Control", "max-age=0");
    }

    private E resultDtoToExcelDto(R resultDto) {
        if (this.resultDtoToExcelDtoConvertor != null) {
            return this.resultDtoToExcelDtoConvertor.apply(resultDto);
        }
        return BeanConvertUtils.convert(resultDto, this.resultType, this.excelType);
    }

    private List<E> resultDtoToExcelDto(List<R> resultDto) {
        return resultDto.stream().map(this::resultDtoToExcelDto).collect(Collectors.toList());
    }
}