如何读取和下载存储在Bucket中的文件？

时间：2012-11-30 18:11:49

标签： java google-app-engine google-cloud-storage

我正在尝试从我的存储桶中存储PDF文件。该文件没有公共权限，但设置为project-private

我使用以下代码：

String filename = "/gs/" + BUCKETNAME + "/" + FILENAME;
AppEngineFile readableFile = new AppEngineFile(filename);
FileReadChannel readChannel = fileService.openReadChannel(readableFile, false);
BufferedReader reader = new BufferedReader(Channels.newReader(readChannel, "UTF8"));
String line = reader.readLine();
resp.getWriter().println("READ:" + line);
readChannel.close();

在我使用我的服务帐户名称

设置我的Acl之前 
<Entry>
<Scope type="UserByEmail">
  <EmailAddress>
     your-application-id@appspot.gserviceaccount.com
  </EmailAddress>
</Scope>
<Permission>FULL_CONTROL</Permission>
</Entry>

当我运行我的应用程序时，我将在FileReadChannel读取此错误readChannel = fileService.openReadChannel（readableFile，false）;：

java.io.IOException
at com.google.appengine.api.files.FileServiceImpl.translateException(FileServiceImpl.java:615)
at com.google.appengine.api.files.FileServiceImpl.makeSyncCall(FileServiceImpl.java:588)
at com.google.appengine.api.files.FileServiceImpl.open(FileServiceImpl.java:521)
at com.google.appengine.api.files.FileServiceImpl.openForRead(FileServiceImpl.java:481)
at com.google.appengine.api.files.FileServiceImpl.openForRead(FileServiceImpl.java:473)
at com.google.appengine.api.files.FileServiceImpl.openReadChannel(FileServiceImpl.java:197)
at it.tiquadra.webso.controller.MainController.readFile(MainController.java:386)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:43)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:426)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
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$CachedChain.doFilter(ServletHandler.java:1166)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$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 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$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:454)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:461)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:703)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:338)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:330)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:458)
at java.lang.Thread.run(Thread.java:679)
Caused by: com.google.apphosting.api.ApiProxy$ApplicationException: ApplicationError: 8: 
    at java.lang.Thread.getStackTrace(Thread.java:1495)
    at com.google.apphosting.api.ApiProxy.makeSyncCall(ApiProxy.java:107)
    at com.google.apphosting.api.ApiProxy.makeSyncCall(ApiProxy.java:56)
    at com.google.appengine.api.files.FileServiceImpl.makeSyncCall(FileServiceImpl.java:584)
    ... 40 more

Caused by: com.google.apphosting.api.ApiProxy$ApplicationException: ApplicationError: 8: 
    at com.google.net.rpc3.client.RpcStub$RpcCallbackDispatcher$1.runInContext(RpcStub.java:783)
    at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:461)
    at com.google.tracing.TraceContext.runInContext(TraceContext.java:703)
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:338)
    at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:330)
    at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:458)
    at com.google.net.rpc3.client.RpcStub$RpcCallbackDispatcher.rpcFinished(RpcStub.java:823)
    at com.google.net.rpc3.client.RpcStub$RpcCallbackDispatcher.failure(RpcStub.java:814)
    at com.google.net.rpc3.impl.client.RpcClientInternalContext.runCallbacks(RpcClientInternalContext.java:900)
    at com.google.net.rpc3.impl.client.RpcClientInternalContext.finishRpcAndNotifyApp(RpcClientInternalContext.java:803)
    at com.google.net.rpc3.impl.client.RpcNetChannel.afterFinishingActiveRpc(RpcNetChannel.java:1063)
    at com.google.net.rpc3.impl.client.RpcNetChannel.finishRpc(RpcNetChannel.java:911)
    at com.google.net.rpc3.impl.client.RpcNetChannel.handleResponse(RpcNetChannel.java:2267)
    at com.google.net.rpc3.impl.client.RpcNetChannel.messageReceived(RpcNetChannel.java:2068)
    at com.google.net.rpc3.impl.client.RpcNetChannel.access$2000(RpcNetChannel.java:143)
    at com.google.net.rpc3.impl.client.RpcNetChannel$TransportCallback.receivedMessage(RpcNetChannel.java:3129)
    at com.google.net.rpc3.impl.client.RpcChannelTransportData$TransportCallback.receivedMessage(RpcChannelTransportData.java:599)
    at com.google.net.rpc3.impl.wire.RpcBaseTransport.receivedMessage(RpcBaseTransport.java:417)
    at com.google.net.eventmanager.AbstractFutureTask$Sync.innerRun(AbstractFutureTask.java:260)
    at com.google.net.eventmanager.AbstractFutureTask.run(AbstractFutureTask.java:121)
    at com.google.net.eventmanager.EventManagerImpl.runTask(EventManagerImpl.java:578)
    at com.google.net.eventmanager.EventManagerImpl.internalRunWorkerLoop(EventManagerImpl.java:1002)
    at com.google.net.eventmanager.EventManagerImpl.runWorkerLoop(EventManagerImpl.java:884)
    at com.google.net.eventmanager.WorkerThreadInfo.runWorkerLoop(WorkerThreadInfo.java:136)
    at com.google.net.eventmanager.EventManagerImpl$WorkerThread.run(EventManagerImpl.java:1855)

我的代码有什么问题？ 感谢

2 个答案:

答案 0 :(得分：0)

您的读者正在使用utf8这是一种字符编码。 PDF是二进制文件。尝试使用字节流进行读取。

答案 1 :(得分：0)

我建议将BlobReader类与BlobKey一起使用，该BlobKey指向云存储中的对象。

您可以使用createGsBlobKey生成BlobKey。

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