asp.net 知名网站,策划公司口号,健康类网站模板,怎么做淘宝联盟的推广网站一、背景
有个需求是这样的#xff0c;客户端直接通过外网访问oss获取图片需要额外付费#xff0c;考虑到成本问题#xff0c;修改技术方案为#xff1a;客户端将请求链接发给后端#xff0c;后端根据请求做一定的截取或拼接#xff0c;通过内网调用oss#xff0c;再将…一、背景
有个需求是这样的客户端直接通过外网访问oss获取图片需要额外付费考虑到成本问题修改技术方案为客户端将请求链接发给后端后端根据请求做一定的截取或拼接通过内网调用oss再将下载下来的图片流返回给前端。 图片流展现在页面上就是直接返回一张图片在浏览器上。 二、具体代码展示
前端期望如果异常直接把http status返回非200
Slf4j
RestController
public class PictureController {Autowiredprivate PictureService pictureService;RequestMapping(value getPicture)public void getPicture(String path, HttpServletResponse resp) {boolean picSuccess;// 注意一定要有这步否则图片显示不出来resp.setContentType(MediaType.IMAGE_JPEG_VALUE);long start System.currentTimeMillis();try {picSuccess pictureService.getOssPicture(path, resp);if (!picSuccess) {resp.setStatus(HttpServletResponse.SC_FORBIDDEN);}} catch (Exception e) {resp.setStatus(HttpServletResponse.SC_FORBIDDEN);log.error(下载图片失败);}log.info(cmd/getPicture,param{},cost:{}, path, System.currentTimeMillis() - start);}
}
public interface PictureService {boolean getOssPicture(String path, HttpServletResponse resp) throws IOException;
}
Slf4j
Service
public class PictureServiceImpl implements PictureService {Value(${alioss.ak})private String accessKeyId;// http://*********.aliyuncs.comValue(${url.prefix})private String urlPrefix;Value(${oss.connect.time:3000})private int ossConnectTime;Overridepublic boolean getOssPicture(String path, HttpServletResponse resp) throws IOException {String url getOssUrl(path);long st System.currentTimeMillis();Request requestDownload new Request.Builder().url(url).build();OkHttpClient client new OkHttpClient();client client.newBuilder().connectTimeout(ossConnectTime, TimeUnit.MILLISECONDS).build();Response responseDownload client.newCall(requestDownload).execute();if (responseDownload.isSuccessful() responseDownload.body() ! null responseDownload.body().byteStream() ! null) {InputStream is responseDownload.body().byteStream();writeImageFile(resp, is);} else {log.error(PictureServiceImpl-oss调用返回异常 url{}, data{}, url, responseDownload);return false;}long responseTime System.currentTimeMillis() - st;log.info(request-oss cost:{}, responseTime);return true;}// base64解码这块是与前端约定好的我这边要做的解码private String getOssUrl(String path) throws UnsupportedEncodingException {final Base64.Decoder decoder Base64.getDecoder();String decodePath new String(decoder.decode(path), UTF-8);StringBuffer buffer new StringBuffer();String[] split decodePath.split();for (int i 0; i split.length; i) {if (!split[i].startsWith(Version)) {buffer.append(split[i]).append();}}log.info(getOssUrl{}, urlPrefix buffer);buffer.append(OSSAccessKeyId).append(accessKeyId);return urlPrefix buffer;}/*** 将输入流输出到页面** param resp* param inputStream*/public void writeImageFile(HttpServletResponse resp, InputStream inputStream) {OutputStream out null;try {out resp.getOutputStream();int len 0;byte[] b new byte[1024];while ((len inputStream.read(b)) ! -1) {out.write(b, 0, len);}out.flush();} catch (IOException e) {e.printStackTrace();} finally {try {if (out ! null) {out.close();}} catch (Exception e) {e.printStackTrace();}}}
}
三、总结
上面就是返回图片流的方式
记录下
