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DiskFile - empty file

I have a web based application that uses DiskFile to upload a file from the harddrive, stores it in a specific location and adds it to a database, however, if the file is empty, ie. has valid name and extension but nothing in it (such as a blank txt file) - it doesn't work, not throwing any errors, seems to just hang?
what's up with that?

can anyone explain, is this a known issue, and how should i catch it?
thanks.
blu.

CEHJ

Can you post your reading code please?

blue-genie

ASKER

i'm thinking it's something to do with this bit but my java knowledge ain't good enough to be sure.

      fileToWrite.createNewFile();
            FileOutputStream fos = new FileOutputStream(fileToWrite);
            FileChannel fco = fos.getChannel();
            int sz = (int)fc.size();
            //int bufferSize = 16384;
            ByteBuffer bb = ByteBuffer.allocate (sz);
            // make our file and output stream
            int nbytes = -1;
            int totBytes = 0;
            while ( (nbytes=fc.read(bb) )!= -1)
            {
                  logger.debug("Bytes written: " + bb);
                  bb.rewind();
                  int writBytes = fco.write(bb);
                  fco.force(false);
                  bb.clear();
            }

CEHJ

>>int sz = (int)fc.size();

Make sure sz is > 0 before proceeding

blue-genie

ASKER

how should i handle it? let them load an empty file? or notify them and stop it?

Mick Barry

check what line it is hanging on.

blue-genie

ASKER

what exactly does the filechannel do?

CEHJ

>>let them load an empty file?

You may as well - i.e. let them *think* they're doing something, but do nothing. What's the point otherwise?

SOLUTION

CEHJ

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blue-genie

ASKER

ok, this is rather odd,
i've changed it as such...

if (sz == 0){
                  request.setAttribute("empty", "y");
            } else {
            //int bufferSize = 16384;
            ByteBuffer bb = ByteBuffer.allocate (sz);
            // make our file and output stream
            int nbytes = -1;
            int totBytes = 0;
            while ( (nbytes=fc.read(bb) )!= -1)
            {
                  logger.debug("Bytes written: " + bb);
                  bb.rewind();
                  int writBytes = fco.write(bb);
                  fco.force(false);
                  bb.clear();
            }
            }

but now, it seems to be working, uploads the file, but the logic present is not happening - does this mean it aint' zero

CEHJ

>>but the logic present is not happening

What do you mean by that? Are you getting logging messages?

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Mick Barry

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blue-genie

ASKER

yeah that always freaks me out when i don't do anything and the code starts working, will get back to u'all.

Mayank S

Maybe you were using an older version of your class-file and it just needed a recompilation/ re-deployment ;-)