以下方法将获取图像并将其保存为GAE blobstore：
public static BlobKey saveFetchedImage(String strUrl, String fileName){
AppEngineFile file = null;
FileService fileService = FileServiceFactory.getFileService();
BlobKey blobKey = null;
try{
URL url = new URL(strUrl);
InputStream is = url.openStream ();
file = fileService.createNewBlobFile("image/jpeg", fileName);
boolean lock = true;
FileWriteChannel writeChannel = fileService.openWriteChannel(file, lock);
byte[] buffer = new byte[1024];
while( is.read(buffer) >= 0) {
ByteBuffer bb = ByteBuffer.wrap(buffer);
writeChannel.write(bb);
}
writeChannel.closeFinally();
is.close();
blobKey = fileService.getBlobKey(file);
}catch(IOException ex){
System.out.println("URL: " + strUrl);
System.out.println("IOException - savedFethedImage: " + ex.getMessage());
}catch(Exception e){
System.out.println("URL: " + strUrl);
System.out.println("Exception - saveFetchedImage:" + e.getMessage());
}
return blobKey;
}
以前在尝试获取20个图像的URL时有效。一组新的100个图像URL有错误。我不确定导致错误的原因是"URL: " + strUrl未被打印。
当错误被抛出时，页面重定向到appspot.com/_ah/upload/someString，显示以下错误：
Uncaught exception from servlet
java.io.IOException
at com.google.appengine.api.files.FileServiceImpl.translateException(FileServiceImpl.java:617)
at com.google.appengine.api.files.FileServiceImpl.makeSyncCall(FileServiceImpl.java:590)
at com.google.appengine.api.files.FileServiceImpl.read(FileServiceImpl.java:539)
at com.google.appengine.api.files.FileServiceImpl.read(FileServiceImpl.java:410)
at com.google.appengine.api.files.FileReadChannelImpl.read(FileReadChannelImpl.java:73)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:272)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:324)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:176)
at java.io.BufferedReader.read1(BufferedReader.java:202)
at java.io.BufferedReader.read(BufferedReader.java:278)
at java.io.BufferedReader.fill(BufferedReader.java:153)
at java.io.BufferedReader.readLine(BufferedReader.java:316)
at java.io.BufferedReader.readLine(BufferedReader.java:379)
at au.com.bytecode.opencsv.CSVReader.getNextLine(Unknown Source)
at au.com.bytecode.opencsv.CSVReader.readNext(Unknown Source)
at dating.admin.UploadProfiles.doPost(UploadProfiles.java:74)
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$CachedChain.doFilter(ServletHandler.java:1166)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:81)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:100)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:249)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:135)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:477)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251)
at java.lang.Thread.run(Thread.java:679)
Caused by: com.google.apphosting.api.ApiProxy$ApplicationException: ApplicationError: 10:
at java.lang.Thread.getStackTrace(Thread.java:1495)
at com.google.apphosting.runtime.ApiProxyImpl.doSyncCall(ApiProxyImpl.java:237)
at com.google.apphosting.runtime.ApiProxyImpl.access$000(ApiProxyImpl.java:68)
at com.google.apphosting.runtime.ApiProxyImpl$1.run(ApiProxyImpl.java:182)
at com.google.apphosting.runtime.ApiProxyImpl$1.run(ApiProxyImpl.java:180)
at java.security.AccessController.doPrivileged(Native Method)
at com.google.apphosting.runtime.ApiProxyImpl.makeSyncCall(ApiProxyImpl.java:180)
at com.google.apphosting.runtime.ApiProxyImpl.makeSyncCall(ApiProxyImpl.java:68)
at com.google.apphosting.api.ApiProxy.makeSyncCall(ApiProxy.java:101)
at com.google.apphosting.api.ApiProxy.makeSyncCall(ApiProxy.java:50)
at com.google.appengine.api.files.FileServiceImpl.makeSyncCall(FileServiceImpl.java:586)
... 48 more
Caused by: com.google.apphosting.api.ApiProxy$ApplicationException: ApplicationError: 10:
at com.google.apphosting.runtime.ApiProxyImpl$AsyncApiFuture.failure(ApiProxyImpl.java:546)
at com.google.net.rpc3.client.RpcStub$RpcCallbackDispatcher$1.runInContext(RpcStub.java:784)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
at com.google.net.rpc3.client.RpcStub$RpcCallbackDispatcher.rpcFinished(RpcStub.java:824)
at com.google.net.rpc3.client.RpcStub$RpcCallbackDispatcher.failure(RpcStub.java:815)
at com.google.net.rpc3.impl.client.RpcClientInternalContext.runCallbacks(RpcClientInternalContext.java:895)
at com.google.net.rpc3.impl.client.RpcClientInternalContext.finishRpcAndNotifyApp(RpcClientInternalContext.java:798)
at com.google.net.rpc3.impl.client.RpcNetChannel.afterFinishingActiveRpc(RpcNetChannel.java:1059)
at com.google.net.rpc3.impl.client.RpcNetChannel.finishRpc(RpcNetChannel.java:907)
at com.google.net.rpc3.impl.client.RpcNetChannel.handleResponse(RpcNetChannel.java:2255)
at com.google.net.rpc3.impl.client.RpcNetChannel.messageReceived(RpcNetChannel.java:2062)
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:3117)
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.rpc3.impl.wire.RpcClientTcpTransport.parseOneMessage(RpcClientTcpTransport.java:750)
at com.google.net.rpc3.impl.wire.RpcClientTcpTransport.parseMessages(RpcClientTcpTransport.java:634)
at com.google.net.rpc3.impl.wire.RpcClientTcpTransport.access$100(RpcClientTcpTransport.java:37)
at com.google.net.rpc3.impl.wire.RpcClientTcpTransport$1.dataReceived(RpcClientTcpTransport.java:295)
at com.google.net.async3.SocketConnection.handleNetworkReadEvent(SocketConnection.java:900)
at com.google.net.async3.SocketConnection.access$400(SocketConnection.java:43)
at com.google.net.async3.SocketConnection$NetworkReadHandlerImpl.run(SocketConnection.java:929)
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:1...(length 8274)
上述代码有任何问题吗？我知道fileService仍处于试验模式。我错过了什么吗？
答案 0 :(得分：1)
尝试以下方法：
byte[] buffer = new byte[1024];
int bytesRead = is.read(buffer, 0, buffer.length);
while( bytesRead >= 0) {
ByteBuffer bb = ByteBuffer.wrap(buffer, 0, bytesRead);
writeChannel.write(bb);
bytesRead = is.read(buffer, 0, buffer.length);
}