How to copy a file from web service to a remote client?

[Guest]

I have made a test: copy a text file to clinet side. But fails.
What I did is that create a web method in web services that read a text in
server side and return the text file as string. On the client side, the
method is called in a windows form client which stores the string and write
the string to a file. Though the file contains the original content but it
just a one-line string which is not the original copy.


Is there a general model which can copy the original file (any type) from
Web services server side to a remote client side? How to do that?

Thanks for any hint and help.

David

 

[Guest]

I can handle text file correctly by spliting string by token. But how to
handle other types of files, for example, binary files.

David

 

[jasonkester]

Could you go into a bit more detail as to what you've tried?
Specifically, are you setting the content-type, clearing the cache, and
streaming the file across? If so, what errors are you seeing? Does
the code below look familiar? If so, you're at least on the right
track.

Response.ContentType = yourContentType; // ie.,
"application/vnd.ms-excel";
Response.AddHeader("content-disposition", "attachment; filename=" +
FileName);
Response.Write(yourFileContent);
Response.End();

Jason Kester
Expat Software Consulting Services
http://www.expatsoftware.com/

 

[Guest]

I do not go this way (HTTP request/response). I created a XML web services
class, say A, on werver side which contains Webmethods that will be called by
the proxy at lient side. Those webmethods read files in server side and
return the file content as a string. In client side, I create a windows form
application, B, which generates a proxy A' of A and uses A' to call those
Webmethods and gets the string of the file content. So I could virtually copy
a file from Server side to the Client side.

Is there a general model to it for any type of file?

David

 

[jasonkester]

No.

If you're using .NET's built-in SOAP functionality, you're going to be
dealing in XML files. This pretty much limits your returned content to
plain text. You'll probably run into much more pain trying to work
around all the issues you'll run into than you would dealing with a
simple HttpRequest to an .aspx.

Jason Kester
Expat Software Consulting Services
http://www.expatsoftware.com/

 

[Guest]

But I want to use windows application in client side as thick client (not web
client). The reason is that we have some larger windows based applications
which read and process image files locally (not common use on web such as
jpg, gif, ...). So I need to build a database which indicates the files
location and get the files from remote server. What can I do? use COM/DCOM,
winsocket, or embedded an application into HTML web browser? Based on your
experience and knowledge, what is the better way to do it?

I know how to embedded Java applet into HTML. How about MS windows
application?

Thank you for your help.

 

[Guest]

When I read XML Web Services book, it states that we can use this kind of
technology to transfer Text file and binary files, but I can not find any
example.

By the way, when they talk about binary serialized od Web Services, what
does it exactly mean?

David

 

[jasonkester]

But I want to use windows application in client side as thick client (not web
client).

Right. That was assumed. Remember, the SOAP web service you are
trying to build is doing a HTTP post behind the scenes. Its
abstraction appears to be hindering you in this case rather than
helping. Thus, you are probably better off deconstructing the process.

So again, try looking at the HttpRequest object from your winform code.
Build a simple .aspx page to act as your web service and document
server. Your client HttpRequest will give you a HttpResponse that will
contain document information, a filename, and a Stream that you can use
to store the document locally. Here is a bit of code that might get
you pointed in the right direction:


HttpWebRequest webRequest = WebRequest.Create(url) as HttpWebRequest;
webRequest.Method = "GET";

HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();
BinaryReader responseReader = new
BinaryReader(response.GetResponseStream());

if (response.ContentLength > -1)
{
byte[] buffer = new byte[response.ContentLength];

FileStream fs = new FileStream(fileName, FileMode.Create);
BinaryWriter writer = new BinaryWriter(fs);

long pos=0;
int count=1;
while (count > 0 && pos < response.ContentLength)
{
count = responseReader.Read(buffer, (int)pos,
(int)(response.ContentLength - pos));
writer.Write( buffer, (int)pos, count);
pos += count;
}

writer.Close();
fs.Close();
}



Jason Kester
Expat Software Consulting Services
http://www.expatsoftware.com/

 

[Guest]

Thank you, Jason. I will try it.

Your whole sample code is for windows client, is that right?
And url should point to the file location and name at the web server side.

David

But I want to use windows application in client side as thick client (not web
client).

Right. That was assumed. Remember, the SOAP web service you are
trying to build is doing a HTTP post behind the scenes. Its
abstraction appears to be hindering you in this case rather than
helping. Thus, you are probably better off deconstructing the process.

So again, try looking at the HttpRequest object from your winform code.
Build a simple .aspx page to act as your web service and document
server. Your client HttpRequest will give you a HttpResponse that will
contain document information, a filename, and a Stream that you can use
to store the document locally. Here is a bit of code that might get
you pointed in the right direction:


HttpWebRequest webRequest = WebRequest.Create(url) as HttpWebRequest;
webRequest.Method = "GET";

HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();
BinaryReader responseReader = new
BinaryReader(response.GetResponseStream());

if (response.ContentLength > -1)
{
byte[] buffer = new byte[response.ContentLength];

FileStream fs = new FileStream(fileName, FileMode.Create);
BinaryWriter writer = new BinaryWriter(fs);

long pos=0;
int count=1;
while (count > 0 && pos < response.ContentLength)
{
count = responseReader.Read(buffer, (int)pos,
(int)(response.ContentLength - pos));
writer.Write( buffer, (int)pos, count);
pos += count;
}

writer.Close();
fs.Close();
}



Jason Kester
Expat Software Consulting Services
http://www.expatsoftware.com/