@GetMapping("/downLoadImage")public void downLoadImage(String fileName, HttpServletResponse response) {if (StringUtils.isNotBlank(fileName)) {OSSObject ossObject = downLoadImage(fileName);if (ossObject != null) {InputStream inputStream = ossObject.getObjectContent();int buffer = 1024 * 10;byte data[] = new byte[buffer];try {response.setContentType("application/octet-stream");// 文件名可以任意指定response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName,"UTF-8"));//将文件名转为ASCLL编码int read;while ((read = inputStream.read(data)) != -1) {response.getOutputStream().write(data, 0, read);}response.getOutputStream().flush();response.getOutputStream().close();ossObject.close();} catch (UnsupportedEncodingException e) {// TODO Auto-generated catch block
                    e.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch block
                    e.printStackTrace();}}}}public OSSObject downLoadImage(String fileName) {OSSClient ossClient = getInstance();Date expiration = new Date(new Date().getTime() + 3600 * 1000);GeneratePresignedUrlRequest request = new GeneratePresignedUrlRequest(bucketName, fileName, HttpMethod.GET);// 设置过期时间。
        request.setExpiration(expiration);// 生成签名URL（HTTP GET请求）。URL signedUrl = ossClient.generatePresignedUrl(request);// 使用签名URL发送请求。Map<String, String> customHeaders = new HashMap<String, String>();// 添加GetObject请求头。//customHeaders.put("Range", "bytes=100-1000");OSSObject object = ossClient.getObject(signedUrl, customHeaders);return object;}public static synchronized OSSClient getInstance() {OSSClient ossClient = connInstances.get("oss");if (ossClient == null) {synchronized (FileUploadServiceImpl.class) {if (ossClient == null) {ossClient = new OSSClient(endpoint, accessKeyId, accessKeySecret);}}}return ossClient;}