内容简介:翻译自:https://stackoverflow.com/questions/35230940/send-image-data-to-android-app-from-app-engine
在我的App Engine后端,我有一种方法可以从Google云端存储中获取图像
@ApiMethod( name = "getProfileImage", path = "image", httpMethod = ApiMethod.HttpMethod.GET) public Image getProfileImage(@Named("imageName")String imageName){ try{ HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport(); GoogleCredential credential = GoogleCredential.getApplicationDefault(); Storage.Builder storageBuilder = new Storage.Builder(httpTransport,new JacksonFactory(),credential); Storage storage = storageBuilder.build(); Storage.Objects.Get getObject = storage.objects().get("mybucket", imageName); ByteArrayOutputStream out = new ByteArrayOutputStream(); // If you're not in AppEngine, download the whole thing in one request, if possible. getObject.getMediaHttpDownloader().setDirectDownloadEnabled(false); getObject.executeMediaAndDownloadTo(out); byte[] oldImageData = out.toByteArray(); out.close(); ImagesService imagesService = ImagesServiceFactory.getImagesService(); return ImagesServiceFactory.makeImage(oldImageData); }catch(Exception e){ logger.info("Error getting image named "+imageName); } return null; }
我遇到的问题是当我在Android应用程序中调用图像数据时如何获取图像数据?
由于你无法从app引擎返回原语,我将其转换为Image,以便我可以在我的应用程序中调用getImageData()来获取byte [].
但是,返回到应用程序的Image对象与app引擎中的Image对象不同,因此没有getImageData().
如何将图像数据导入我的Android应用程序?
如果我创建一个其中包含byte []变量的Object,那么我将byte []变量设置为字符串数据并从该方法返回该对象将起作用吗?
更新
图像从Android应用程序发送. (此代码可能正确也可能不正确,我还没有调试过)
@WorkerThread public String startResumableSession(){ try{ File file = new File(mFilePath); long fileSize = file.length(); file = null; String sUrl = "https://www.googleapis.com/upload/storage/v1/b/lsimages/o?uploadType=resumable&name="+mImgName; URL url = new URL(sUrl); HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection(); urlConnection.setRequestProperty("Authorization",""); urlConnection.setRequestProperty("X-Upload-Content-Type","image/png"); urlConnection.setRequestProperty("X-Upload-Content-Length",String.valueOf(fileSize)); urlConnection.setRequestMethod("POST"); if(urlConnection.getResponseCode() == HttpURLConnection.HTTP_OK){ return urlConnection.getHeaderField("Location"); } }catch(Exception e){ e.printStackTrace(); } return null; } private long sendNextChunk(String sUrl,File file,long skip){ int bytesRead, bytesAvailable, bufferSize; byte[] buffer; int maxBufferSize = 524287; long totalBytesSent = 0; try{ long fileSize = file.length(); FileInputStream fileInputStream = new FileInputStream(file); skip = fileInputStream.skip(skip); bytesAvailable = fileInputStream.available(); bufferSize = Math.min(bytesAvailable, maxBufferSize); totalBytesSent = skip + bufferSize; buffer = new byte[bufferSize]; bytesRead = fileInputStream.read(buffer, 0, bufferSize); try { while (bytesRead > 0) { try { URL url = new URL(sUrl); HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection(); urlConnection.setDoInput(true); urlConnection.setDoOutput(true); urlConnection.setUseCaches(false); urlConnection.setChunkedStreamingMode(524287); urlConnection.setRequestMethod("POST"); urlConnection.setRequestProperty("Connection", "Keep-Alive"); urlConnection.setRequestProperty("Content-Type","image/png"); urlConnection.setRequestProperty("Content-Length",String.valueOf(bytesRead)); urlConnection.setRequestProperty("Content-Range", "bytes "+String.valueOf(skip)+"-"+String.valueOf(totalBytesSent)+"/"+String.valueOf(fileSize)); DataOutputStream outputStream = new DataOutputStream(urlConnection.getOutputStream()); outputStream.write(buffer, 0, bufferSize); int code = urlConnection.getResponseCode(); if(code == 308){ String range = urlConnection.getHeaderField("Range"); return Integer.parseInt(range.split("-")[1]); }else if(code == HttpURLConnection.HTTP_CREATED){ return -1; } outputStream.flush(); outputStream.close(); outputStream = null; } catch (OutOfMemoryError e) { e.printStackTrace(); // response = "outofmemoryerror"; // return response; return -1; } fileInputStream.close(); } } catch (Exception e) { e.printStackTrace(); // response = "error"; // return response; return -1; } }catch(Exception e){ e.printStackTrace(); } return -1; }
编辑2:
显然,人们不清楚我在我的Android应用程序中使用端点
我最终做了什么/发现你需要在带端点的api调用上调用execute()并返回从API传回的实际数据
例
api调用返回Image
public Image getProfileImage(@Named("id") long id, @Named("imageName")String imageName){ try{ ProfileRecord pr = get(id); HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport(); GoogleCredential credential = GoogleCredential.getApplicationDefault(); Storage.Builder storageBuilder = new Storage.Builder(httpTransport,new JacksonFactory(),credential); Storage storage = storageBuilder.build(); Storage.Objects.Get getObject = storage.objects().get("mybucket", imageName); ByteArrayOutputStream out = new ByteArrayOutputStream(); // If you're not in AppEngine, download the whole thing in one request, if possible. getObject.getMediaHttpDownloader().setDirectDownloadEnabled(false); getObject.executeMediaAndDownloadTo(out); byte[] oldImageData = out.toByteArray(); out.close(); return ImagesServiceFactory.makeImage(oldImageData); }catch(Exception e){ logger.info("Error getting image named "+imageName); } return null; }
然后在客户端我会这样称呼它来获得它
Image i = pr.profileImage(id,"name.jpg").execute(); byte[] data = i.decodeImageData();
翻译自:https://stackoverflow.com/questions/35230940/send-image-data-to-android-app-from-app-engine
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