文件下载的写法

private void download(String token, String guid, HttpServletRequest req, HttpServletResponse resp) {
        File outputFile = null;
        try {
            EdmConfig config = getEdmConfig(token);
            // 请求参数类
            ExcelTaskRequestVO requestVO = new ExcelTaskRequestVO();

            UserVO user = (UserVO) RequestContext.getCurrent().getUser();
            // 当前用户id
            requestVO.setUserId(String.valueOf(user.getUserId()));
            // 创建人
            requestVO.setCreatedBy(user.getUserAccount());
            // Excel引擎访问地址
            requestVO.setServiceUrl(edmEndPoint);
            // 导出任务的GUID
            requestVO.setGuid(guid);
            EdmExcelClient excelClient = new EdmExcelClient(config);
            int times = 0; // 防止无限循环
            String edmStatus = getEdmStatus(excelClient, requestVO);
            while (times < 10 && !"FINISH".equals(edmStatus)) {
                try {
                    Thread.sleep(500);
                    LOGGER.info("sleep 500 millisecond for download finish");
                } catch (InterruptedException e) {
                    LOGGER.info("sleep download finish InterruptedException:", e);
                }
                times++;
                edmStatus = getEdmStatus(excelClient, requestVO);
            }
            ResponseObject responseObject = excelClient.download(requestVO);
            if (responseObject != null && responseObject.getStatus() == 200) {
                Headers headers = responseObject.getResponseHeaders();
                if (headers == null) {
                    LOGGER.error("-------------------headers == null-------------------");
                    return;
                }
                String contentType = headers.get("Content-Type");
                if ("application/json;charset=UTF-8".equals(contentType)) {
                    LOGGER.debug("do nothing");
                    // JSON反序列化
                } else if ("application/octet-stream;charset=UTF-8".equals(contentType)) {
                    // 方式一：不经过服务器，但是文件名改不了
                    /*
                     * resp.setContentType("application/octet-stream");
                     * String disposition = responseObject.getResponseHeaders().get("Content-Disposition");
                     * Pattern pattern = Pattern.compile("attachment;filename=(.*?)$", Pattern.CASE_INSENSITIVE);
                     * Matcher matcher = pattern.matcher(disposition);
                     * if (matcher.find()) {
                     * String filename = URLDecoder.decode(matcher.group(1), CharsetNames.CS_UTF8);
                     * resp.setHeader("Content-Disposition", "attachment;filename=" + filename);
                     * }
                     * resp.setCharacterEncoding(CharsetNames.CS_UTF8);
                     * InputStream input = responseObject.getByteStream();
                     * OutputStream output = resp.getOutputStream();
                     * StreamUtil.transfer(input, output);
                     */

                    // 方式二：先存到服务器再下载，这个中文文件名会乱码
                    FileInfoVO fileInfoVO = new FileInfoVO();
                    String disposition = responseObject.getResponseHeaders().get("Content-Disposition");
                    Pattern pattern = Pattern.compile("attachment;filename=(.*?)$", Pattern.CASE_INSENSITIVE);
                    if (disposition != null) {
                        Matcher matcher = pattern.matcher(disposition);
                        if (matcher.find()) {
                            String filename = URLDecoder.decode(matcher.group(1), CharsetNames.CS_UTF8);
                            fileInfoVO.setDisplayName(filename);
                            String outputFilePath = System.getProperty("java.io.tmpdir") + filename;
                            String checkOutputFilePath = StringVerifyUtil.dealSpecialChar(outputFilePath);
                            outputFile = new File(checkOutputFilePath);
                            IOUtils.copyTo(responseObject.getByteStream(), outputFile.getCanonicalPath(), 1024);
                            // just for cloud dragon
                            setFileInfoVo(outputFile, fileInfoVO);
                        }
                    }
                    downloadOutput(req, resp, fileInfoVO);
                }
            }
        } catch (EdmException | IOException | DownloadException e) {
            LOGGER.error("download error:", e);
        } finally {
            if (outputFile != null) {
                boolean delFlag = outputFile.delete();
                if (!delFlag) {
                    LOGGER.info("outputFile delete failed");
                }
            }
        }
    }

    private void setFileInfoVo(File outputFile, FileInfoVO fileInfoVo) {
        InputStream in = null;
        try {
            File checkFile = StringVerifyUtil.checkFilePath(outputFile);
            in = new FileInputStream(checkFile);
            final ByteArrayOutputStream baoS = new ByteArrayOutputStream();
            final byte[] buffer = new byte[1024];
            int len;
            while ((len = in.read(buffer)) > -1) {
                baoS.write(buffer, 0, len);
            }
            baoS.flush();

            fileInfoVo.setInputStream(new ByteArrayInputStream(baoS.toByteArray()));
            fileInfoVo.setStream(true);
        } catch (IOException e) {
            LOGGER.info("IOException ", e);
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    LOGGER.error(e.getMessage(), e);
                }
            }
        }
    }

    private void downloadOutput(HttpServletRequest req, HttpServletResponse resp, FileInfoVO file)
        throws DownloadException {
        InputStream in = null;
        OutputStream out = null;
        try {
            // 尝试下载文件
            // 根据浏览器判断下载文件名转义 wx244051 2016-01-14
            String agent = req.getHeader("User-Agent").toLowerCase();

            in = file.getInputStream();
            if (in != null) {
                if (agent.contains("msie") || agent.contains("trident")) {
                    download.outputFromStream(req, resp, in, file.getDisplayName(), true, 0L);
                } else {
                    download.outputFromStream(req, resp, in,
                        new String(file.getDisplayName().getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1),
                        false, 0L);
                }
            }
        } catch (FileNotFoundException e) {
            LOGGER.error("mkpVerticalPrice file not found -- ", e);
            throw new DownloadException("honor.jalor5.download.support.00010002");
        } catch (Exception e) {
            LOGGER.error("mkpVerticalPrice download error -- ", e);
            throw new DownloadException("honor.jalor5.download.support.00010001");
        } finally {
            StreamUtil.closeStreams(in, out);
        }
    }

 

private void downloadExcel(HttpServletRequest req, HttpServletResponse resp, File file) {
        InputStream in = null;
        DownloadOutput download = new DownloadOutput();
        try {
            // 尝试下载文件
            // 根据浏览器判断下载文件名转义
            String agent = req.getHeader("User-Agent").toLowerCase();
            File checkFile = StringVerifyUtil.getValidDirectoryPath(file);
            in = new FileInputStream(checkFile);
            if (agent.contains("msie") || agent.contains("trident")) {
                download.outputFromStream(req, resp, in, file.getName(), true, 0L);
            } else {
                download.outputFromStream(req, resp, in,
                    new String(file.getName().getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1), false,
                    0L);
            }
        } catch (FileNotFoundException e) {
            LOGGER.error("Price Authorization Letter file not found -- ", e);
        } catch (Exception e) {
            LOGGER.error("Price Authorization Letter download error -- ", e);
        } finally {
            StreamUtil.closeStreams(in);
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    LOGGER.error(e.getMessage(), e);
                }
            }
        }
        if (file.delete()) {
            LOGGER.info("Price Authorization Letter tmp file delete success -- ");
        }
    }