通常,要从BlobKey获取网址,我只需执行
public static String getUrlFromKey(BlobKey blobKey) {
if(null == blobKey)return null;
ServingUrlOptions options = ServingUrlOptions.Builder.withBlobKey(blobKey).secureUrl(false);
String servingUrl = ImagesServiceFactory.getImagesService().getServingUrl(options);
return servingUrl;
}
但我现在得到一个例外,我说服原因是因为这次Blobkey是用于视频而不是图像。那么如何根据视频的Blobkey获取网址?
对于某些背景,我正在为我的Android应用程序使用Cloud Endpoint App-Engine服务器。将视频上传到Blobstore后,我需要能够从我的Android设备上观看。因此,如果无法按照图像的方式获取网址,是否有办法从端点方法提供服务?
错误:
com.google.appengine.api.images.ImagesServiceFailureException:
at com.google.appengine.api.images.ImagesServiceImpl.getServingUrl(ImagesServiceImpl.java:284)
at com.mycompany.utils.BlobstoreUtils.getUrlFromKey(BlobstoreUtils.java:21)
at com.mycompany.servlet.VideoUploadCallback.doPost(VideoUploadCallback.java:44)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.googlecode.objectify.ObjectifyFilter.doFilter(ObjectifyFilter.java:48)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:123)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:37)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:60)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:260)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:78)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:147)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:457)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:230)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:235)
at java.lang.Thread.run(Thread.java:745)
答案 0 :(得分:0)
来自文档:
要提供blob,必须包含blob下载处理程序作为路径 你的申请。这个处理程序应该传递blob键 所需blob到blobstoreService.serve(blobKey,res);.在这 例如,blob密钥作为URL传递给下载处理程序 参数(req.getParameter('blob-key'))。在实践中,下载 handler可以通过您选择的任何方式获取blob密钥,例如through 另一种方法或用户操作。
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws IOException {
BlobKey blobKey = new BlobKey(req.getParameter("blob-key"));
blobstoreService.serve(blobKey, res);
使用Google Cloud Storage而不是Blobstore。然后,您可以直接投放视频 - 只需传递视频的网址,而无需通过您的应用程序。