how to send xml file

  • Thread starter Thread starter jens d
  • Start date Start date
J

jens d

Hi NG,

I'm trying to send a XML file. The receiver should be able to work with
the content without saving it as a file. (Best with XMLReader, but that
will be part of further postings ;) )

I tried it the following way, but it doesnt work out.
Please have a look at my code:
Sender:

long s_length = FileStream.Length;
long s_read = 0;

StreamWriter sw = new StreamWriter(NetworkStream, Encoding.UTF8, 1024);
using (StreamReader sr=new StreamReader(FileStream, Encoding.UTF8,true))
{
while (s_length > s_read)
{
char[] buffer = new char[1024];
int read = sr.Read(buffer, 0, 1024);
s_read += read;
sw.Write(buffer,0,read);
}
}
NetworkStream.Flush();

One Problem with the sender is that the StreamWriter doesnt seem to send
the buffer every time when sw.Write(..) is called.
Another, that the calculated size (s_read) is not the same as
FileStream.lenth and therefore this ends up in a 'do_nothing_loop' :(
Suggestions??

Receiver:

using (StreamReader sr = new StreamReader(NetworkStream, ENCODING.UTF8))
{
while(true)
{
char[] buffer = new char[1024];
int read = sr.Read(buffer, 0, 1024);
StringBuilder.Append(buffer);
if (read == 0)
break;
}
}

Within the StringBuilder I hoped to find the complete XML-file, but I
only got the first 1024bytes as it seems.
Does anybody see a mistake?
Do you know a better way to send the file?
Somebody done this before? -> Links, Tutorials?

Thanks a lot

Jens
 
Have you tried calling sw.Flush(), after you call sw.Write()?? This should
clear out any internal buffers and write them to the stream.
 
Great Thanks. Now the whole Stream arrives at the Receiver. Another
Problem occured though:

Receiver:

while(true)
{
char[] buffer = new char[1024];
int read = sr.Read(buffer, 0, 1024);
StringBuilder.Append(buffer);
if (read == 0)
break;
}

after receiving the whole Stream, the Loop will hang at sr.Read() and
won't terminate.
Suggestions?
Thanx!!

Jens
 
I'm not entirely sure, but I would refactor this as below; two reasons:

1: could read be -ve?
2: the final read could return a partial buffer (e.g. 47 bytes); you should
then only add those 47 to the string builder

int read = st.Read(buffer, 0, 1024);
if(read>0) {
// append *only what you read*
}
else { // EOF
break;
}

Marc
 
Jens D said:
Great Thanks. Now the whole Stream arrives at the Receiver. Another
Problem occured though:

Receiver:

while(true)
{
char[] buffer = new char[1024];
Click to expand...

move the buffer outside the loop.
int read = sr.Read(buffer, 0, 1024);
StringBuilder.Append(buffer);
Click to expand...

check "read" before Append.

You are using the wrong Append(buffer) = Append(buffer.ToString() =
Append("char[]") or something similar.

You want Append(buffer,0,read)
 
Hi,
Sender:
Click to expand...
StreamWriter sw = new StreamWriter(NetworkStream, Encoding.UTF8, 1024);
Click to expand...

Why are you reading it as a UTF8 if you need to convert it again to byte[] ?
, just read it as a binary file ( using FileStream )
NetworkStream.Flush();
Click to expand...

IIRC you do not need to call Flush in a networkstream , yep I'm correct,
check MSDN

I would rewrite the sender like:
long s_length = FileStream.Length;

networkStream.Write( BitConverter.GetBytes( s_length), 0, 8 ); //send the
size
using (FileStream sr=new FileStream(FileStream) )
{
while (s_length > s_read)
{
byte[] buffer = new byte[1024];
int read = sr.Read(buffer, 0, 1024);
s_read += read;
networkStream.Write(buffer,0,read);
}
}

The receiver is kind of similar, read the size, then create a memorystream
with that size and read that amount of bytes directly to the memorystream,
you can decorate the memorystream with a XmlTextReader
 
Thanx Ignacio,
the sender works fine.

On the side of the receiver the size of the xml-file seems to be larger.
So I won't get the whole stream when using (s_length > s_read) condition.
How come?

Thanks again.
Hi,
Sender:

StreamWriter sw = new StreamWriter(NetworkStream, Encoding.UTF8, 1024);
Click to expand...


Why are you reading it as a UTF8 if you need to convert it again to byte[] ?
, just read it as a binary file ( using FileStream )

NetworkStream.Flush();
Click to expand...


IIRC you do not need to call Flush in a networkstream , yep I'm correct,
check MSDN

I would rewrite the sender like:
long s_length = FileStream.Length;

networkStream.Write( BitConverter.GetBytes( s_length), 0, 8 ); //send the
size
using (FileStream sr=new FileStream(FileStream) )
{
while (s_length > s_read)
{
byte[] buffer = new byte[1024];
int read = sr.Read(buffer, 0, 1024);
s_read += read;
networkStream.Write(buffer,0,read);
}
}

The receiver is kind of similar, read the size, then create a memorystream
with that size and read that amount of bytes directly to the memorystream,
you can decorate the memorystream with a XmlTextReader
Click to expand...
 
Hi again,

actually the receiver is not working fine. The MemoryStream does not
seem to contain any of the data.
Do I handle the Stream wrong?
Thanks again

Receiver:


MemoryStream ms = new MemoryStream();
while(true)
{
buffer = new byte[buffersize];
read = NetworkStream.Read(buffer,0,buffersize);
if(read==0)
break;
ms.Write(buffer,0, buffersize);
}
 
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