fatelpc commented 9 months ago

问题描述，使用Web导出文件是，大对象无法被回收，导致OOM

异常代码

 public void downloadDebugInfo(
            HttpServletResponse response,
            @RequestParam(name = "taskId") String taskId,
            @RequestParam(name = "versionId") String versionId) throws IOException {
        long startTime = System.currentTimeMillis();
        ExportResult exportResult = diffService.getDebugResult(Long.valueOf(taskId), Long.valueOf(versionId));
        long endTime = System.currentTimeMillis();
        long elapsedTime = endTime - startTime;
        log.info("导出计算运行时间：" + elapsedTime + "ms");
        // 接口测试 有同学反应使用swagger 会导致各种问题，请直接用浏览器或者用postman
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        response.setCharacterEncoding("utf-8");
        // 这里URLEncoder.encode可以防止中文乱码
        String fileName = URLEncoder.encode(exportResult.getFileName(), "UTF-8").replaceAll("\\+", "%20");
        response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileName + ".xlsx");
        try (ExcelWriter excelWriter = EasyExcel.write(response.getOutputStream()).build()) {
            if (!CollectionUtils.isEmpty(exportResult.getNoteDebugInfoList())) {
                List<NoteSearchDataExpExcel> noteDebugInfoList = exportResult.getNoteDebugInfoList();
                WriteSheet gsbWriteSheet = EasyExcel.writerSheet(0, "Diff结果").head(NoteSearchDataExpExcel.class).build();
                excelWriter.write(noteDebugInfoList, gsbWriteSheet);
            } else {
                List<NoteFeedDataExpExcel> noteDebugInfoList = exportResult.getNoteFeedDataExpExcelList();
                WriteSheet gsbWriteSheet = EasyExcel.writerSheet(0, "Diff结果").head(NoteFeedDataExpExcel.class).build();
                excelWriter.write(noteDebugInfoList, gsbWriteSheet);
            }
        } catch (Exception e) {
            log.error("scoring export error. ", e);
            throw new DroomException("导出Diff异常");
        } finally {
            exportResult.clear();
            exportResult = null;
            System.gc();
        }
    }