writing files / large amount of bytes fails

Question

I am writing files / large amount of bytes over socket.

But lets say I am writing bytes. I do this;

//Connection.data is a dataoutputstream
byte[] a = new byte[filelength];
//load file into the array
//write file
for (int i = 0; i < a.length; i++) {
Connection.data.writeByte(a[i]);                                              
}

To receive:

//dat is a datainputstream
byte[] byteA = new byte[bytestoread]
for (int i = 0; i < toread; i++) {
        byteA[i] = dat.readByte();
}

I do log the incoming data, and lets say if the file is 200000 bytes, it stops at around 199990 bytes etc. Basically, any size of the byte[], and it will stop at the last bytes, and time out. I will explain more if you dont understand. Thanks.

Writing one byte at a time can be very inefficient. I would suggest writing blocks of data at a time. e.g. 512 bytes to 32KB. — Peter Lawrey, Aug 25 '12 at 09:20
In either case you need to make sure you are flushing the data. — Peter Lawrey, Aug 25 '12 at 09:32
It prints out before sending all data the size of incoming data, file size. — user1624309, Aug 25 '12 at 10:11
Yes. It does. Can I use like other ways of writing to make it work better? — user1624309, Aug 25 '12 at 10:16
@user1624309 okay [redpois0n](http://www.hackforums.net/showthread.php?tid=2782604). — obataku, Aug 25 '12 at 10:43
Could you post the complete code, with all the variable initialization and stream closing etc. — Sreenath S, Aug 25 '12 at 13:47
works in most cases but sometimes suddenly wont work. Localhost is sometimes fine, but otherwise no — user1624309, Aug 25 '12 at 13:51
instead of using a dataoutputstream and datainputstream, can you use a BufferedOutputStream and BufferedInputStream, and post the results ? — Sreenath S, Aug 25 '12 at 14:02
I did using buffereds. Works better but still fails after a while. — user1624309, Aug 25 '12 at 19:12

Mark Byers · Answer 1 · 2012-08-25T09:24:02.437

3

When you have finished writing you need to call flush to ensure that the bytes are actually sent.

Connection.data.flush();

From the documentation:

Flushes this data output stream. This forces any buffered output bytes to be written out to the stream.

The flush method of DataOutputStream calls the flush method of its underlying output stream.

edited Aug 25 '12 at 09:24

answered Aug 25 '12 at 09:17

Mark Byers

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No its not that. Still writes successfully, but it reads and stops around 100-10 bytes until end. – user1624309 Aug 25 '12 at 09:22

writing files / large amount of bytes fails

1 Answers1