[appengine-java] Creating and Retrieving a blobstore file

[Andrew]

Hi,

I'm trying to save a file to the blobstore similar to what is
described in docs at this page:

http://code.google.com/appengine/docs/java/blobstore/overview.html#Writing_Files_to_the_Blobstore

My code to write the file is:


                        // Create a new Blob file with mime-type "text/html"
                        AppEngineFile file = 
fileService.createNewBlobFile("text/html");

                        // Open a channel to write to it
                        boolean lock = true;
                        writeChannel = fileService.openWriteChannel(file, lock);

                        PrintWriter out = new 
PrintWriter(Channels.newWriter(writeChannel,
                                        "UTF8"));
                        out.print(htmlText);

                        // Close without finalizing and save the file path for 
writing
later
                        out.close();
                        filePath = file.getFullPath();
                        writeChannel.closeFinally();

I then save the filePath as a field on one of my Datastore entities.

However when I try and read it back, the following code falls into the
catch for FileNotFound exception:

        public String fetchHtml(String remoteUrl) {
                StringBuilder sb = new StringBuilder();
                String returnString = null;
                FileService fileService = FileServiceFactory.getFileService();

                FixtureEntity fixture = getRecordByRemoteUrl(remoteUrl);
                String fileName = fixture.getFileName();
                AppEngineFile file = new AppEngineFile(fileName);

                FileReadChannel readChannel;
                try {
                        readChannel = fileService.openReadChannel(file, false);

                        BufferedReader reader = new 
BufferedReader(Channels.newReader(
                                        readChannel, "UTF8"));
                        String inputLine;

                        while ((inputLine = reader.readLine()) != null) {
                                sb.append(inputLine);
                        }
                        // line = "The woods are lovely dark and deep."

                        readChannel.close();
                        returnString = sb.toString();
                } catch (FileNotFoundException e) {
                        logger.warning(e.getMessage());
                } catch (LockException e) {
                        logger.warning(e.getMessage());
                } catch (IOException e) {
                        logger.warning(e.getMessage());
                }

                return returnString;
        }

I'm working on the dev server, with SDK v1.6.1.  If I look in the
Datastore Viewer, the fileName is set on my entity to /blobstore/
writable:4IoqzMo2yJHJ7336lvNABg.  There are __BlobInfo__ entities, but
all their "filename" properties are null.

If I do this:


                FileService fileService = FileServiceFactory.getFileService();
                BlobKey key = fileService.getBlobKey(file);
                if (key == null) {
                        Thread.sleep(2000);
                        key = fileService.getBlobKey(file);
                }

Key definitely gets populated.  So I'm not sure why

readChannel = fileService.openReadChannel(file, false);

isn't working.

Can anyone see anything obviously wrong with my code?  Or have any
suggestions as to how to get things  working?

Many thanks in advance,
Andrew.

-- 
You received this message because you are subscribed to the Google Groups 
"Google App Engine for Java" group.
To post to this group, send email to google-appengine-java@googlegroups.com.
To unsubscribe from this group, send email to 
google-appengine-java+unsubscr...@googlegroups.com.
For more options, visit this group at 
http://groups.google.com/group/google-appengine-java?hl=en.