Post XML with HttpWebRequest

[Chakravarthy]

I’m writing a windows application which intern talks to a web interface
exposed at http://194.224.184.162/barceloDS/interface/xml . Now my problem
is, this exposed interface will accept the XML String as parameter and
returns data in XML Format. You can find the example of the XML Input, at
http://194.224.184.162/barceloDS/interface/example, which explains in detail
about the input XML String.

I’m trying to execute the following code, which returning me null text,
instead of some response. Correct me where I’m mistaken.

string GetResp()
{
// This is the XML Input String to the exposed XML Interface
string strReq = @"<?xml version=""1.0"" encoding=""UTF-8""
?><barceloDS_requests><request type=""availability list"" id=""1"">
<session_id></session_id> <language_code>ING</language_code> <agency>
<primary>888</primary> <secondary>88</secondary> <detail>888</detail>
<branch>1</branch> </agency> <contract></contract>
<check_in_date>20060801</check_in_date>
<check_out_date>20060803</check_out_date> <location>
<destination_code>PMI</destination_code> <zone_code></zone_code> </location>
<establishment> <code></code> <category></category> </establishment>
<board_type_code></board_type_code> <occupancy> <adults>2</adults>
<children>1</children> <rooms>1</rooms> </occupancy> </request>
</barceloDS_requests>";

HttpWebRequest hwrRequest = (HttpWebRequest)
HttpWebRequest.Create("http://194.224.184.162/barceloDS/interface/xml");
hwrRequest.Method="POST";
hwrRequest.ContentType = "text/xml";

UTF8Encoding encoding = new UTF8Encoding();
byte[] postBytes = encoding.GetBytes(strReq);

hwrRequest.ContentLength=postBytes.Length;

Stream postStream = hwrRequest.GetRequestStream();
postStream.Write(postBytes,0,postBytes.Length);
postStream.Close();

HttpWebResponse hwrResponse = (HttpWebResponse) hwrRequest.GetResponse();
Stream responseStream = hwrResponse.GetResponseStream();
XmlTextReader xtrSmp = new XmlTextReader(responseStream);

string strXm = xtrSmp.ReadInnerXml();
xtrSmp.Close();
hwrResponse.Close();

return strXm;
}

Regards,
--
Every thing is perfect, as long as you share!!!

[Hans Olav]

Hi.

I would definitely use WebClient instead of the rather messy
HttpWebRequest/Response.
The WebClient class has a method called UploadData which takes a byte array
and a method, and returns a resulting byte array. You can also access header
info using the ResponseHeaders collection.

'Hans Olav.

[Hans Olav]

Here's an example using WebClient. Usually UTF-8 is the standard encoding to
use in both request and response from webservices, but it seems that this
site is using iso-8859-1 encoding, so I've set up both the request and
response bytes to be parsed using iso-8859-1. You can easily change this
back to UTF-8 in the isoEncoding variable...

XmlDocument Doc = new XmlDocument();
WebClient Client = new WebClient();
Encoding isoEncoding = Encoding.GetEncoding("iso-8859-1");
string url = http://194.224.184.162/barceloDS/interface/xml;
string strReq =
@"<?xml version=""1.0""
encoding=""iso-8859-1""?><barceloDS_requests><request type=""availability
list"" id=""1"">
<session_id></session_id> <language_code>ING</language_code> <agency>
<primary>888</primary> <secondary>88</secondary> <detail>888</detail>
<branch>1</branch> </agency> <contract></contract>
<check_in_date>20060801</check_in_date>
<check_out_date>20060803</check_out_date> <location>
<destination_code>PMI</destination_code> <zone_code></zone_code> </location>
<establishment> <code></code> <category></category> </establishment>
<board_type_code></board_type_code> <occupancy> <adults>2</adults>
<children>1</children> <rooms>1</rooms> </occupancy> </request>
</barceloDS_requests>";
byte[] bytesReq = isoEncoding.GetBytes(strReq);
byte[] respBytes = Client.UploadData(url, "POST", bytesReq);
MemoryStream MemStream = new MemoryStream(respBytes, false);
using (StreamReader Reader = new StreamReader(MemStream, isoEncoding))
{
Doc.Load(Reader);
}