[OpenLayers-Users] C# version of Proxy for OpenLayers:Proxy.ashx?url=

[Mark Lidstone]

Ah!  A question I can answer!  :)
 
It's a misuse of the "offset" argument in the script.  If the page had
fit into a single buffer (1024 bytes in that case) the problem wouldn't
have shown up.
 
I've included below a version that I've just put together using my own
code and added the POST support (and a couple of the request headers)
from the code you found on the list:

<%@ WebHandler Language="C#" Class="WfsProxy" %>

using System;
using System.Web;

public class WfsProxy: IHttpHandler {
    
    public void ProcessRequest (HttpContext context) {
        System.Net.WebRequest req =
System.Net.WebRequest.Create(context.Request["u"]);
        if (req is System.Net.HttpWebRequest)
            ((System.Net.HttpWebRequest)req).UserAgent =
context.Request.UserAgent;
        req.ContentType = context.Request.ContentType;
        req.Method = context.Request.HttpMethod;
        
        int nRead = 0;
        byte[] baBuffer = new byte[BUFF_SIZE];
        if (req.Method == "POST")//The WebRequest object takes care of
case for you
        {
            int nTmp = 0;
            while (nTmp < context.Request.ContentLength)
            {
                nRead = context.Request.InputStream.Read(baBuffer, 0,
BUFF_SIZE);
                if (nRead > 0)
                {
                    req.GetRequestStream().Write(baBuffer, 0, nRead);
                    nTmp += nRead;
                }
            }
            req.GetRequestStream().Flush();
            req.GetRequestStream().Close();
        }
        System.Net.WebResponse resp = req.GetResponse();
        context.Response.ContentType = resp.ContentType;
        System.IO.Stream strm = resp.GetResponseStream();
        nRead = strm.Read(baBuffer, 0, BUFF_SIZE);
        System.IO.Stream strmOut = context.Response.OutputStream;
        
        while (nRead != 0)
        {
            strmOut.Write(baBuffer, 0, nRead);
            nRead = strm.Read(baBuffer, 0, BUFF_SIZE);
        }

        strmOut.Flush();
        strmOut.Close();
    }

    private const int BUFF_SIZE = 8192;
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}

I hope this helps,

Mark Lidstone
Senior Software Engineer
Tel: +44 (0)23 80232222; Fax: +44 (0)23 80232891

BMT Cordah Ltd
Grove House
7 Ocean Way
Ocean Village
Southampton
SO14 3TJ



 


________________________________

	From: users-bounces at openlayers.org
[mailto:users-bounces at openlayers.org] On Behalf Of Paul james
	Sent: 08 April 2009 15:20
	To: users at openlayers.org
	Subject: Re: [OpenLayers-Users] C# version of Proxy for
OpenLayers:Proxy.ashx?url=
	
	
	Hello!
	I tried that, but if I test any page like that :
	Proxy.ashx?url=http://www.google.com
	I got a empty blank page...
	
	Any idea?
	P
	
	---------------------------------
	
	<%@ WebHandler Language="C#" Class="Proxy" %>
	
	using System;
	using System.Web;
	using System.Net;
	using System.IO;
	using System.Text;
	using System.Configuration;
	
	
	public class Proxy : IHttpHandler {
	   
	    public void ProcessRequest (HttpContext context) {
	       
	        HttpWebRequest request =
(HttpWebRequest)WebRequest.Create(context.Request["url"]);
	        request.UserAgent = context.Request.UserAgent;
	        request.ContentType = context.Request.ContentType;
	        request.Method = context.Request.HttpMethod;
	
	        byte[] trans = new byte[1024];
	        int offset = 0;
	        int offcnt = 0;
	       
	        if (request.Method.ToUpper() == "POST")
	        {
	            Stream nstream = request.GetRequestStream();
	            while (offset < context.Request.ContentLength)
	            {
	                offcnt = context.Request.InputStream.Read(trans,
offset, 1024);
	                if (offcnt > 0)
	                {
	                    nstream.Write(trans, 0, offcnt);
	                    offset += offcnt;
	                }
	            }
	            nstream.Close();
	        }
	               
	        using (HttpWebResponse response =
(HttpWebResponse)request.GetResponse())
	        {
	            context.Response.ContentType = response.ContentType;
	           
	            using (Stream receiveStream =
response.GetResponseStream())
	            {
	                offset = 0;
	                offcnt = receiveStream.Read(trans, offset,
1024);
	                while (offcnt>0)
	                {
	                    context.Response.OutputStream.Write(trans,
0, offcnt);
	                    offset += offcnt;
	                    if (offcnt >= 0)
	                    {
	                        try
	                        {
	                            offcnt = receiveStream.Read(trans,
offset, 1024);
	                        }
	                        catch (Exception)
	                        {
	                            break;
	                        }
	                    }
	                    else
	                        break;        
	                }
	            }
	            context.Response.OutputStream.Close();
	            context.Response.Flush();
	            response.Close();
	        }
	    }
	 
	    public bool IsReusable {
	        get {
	            return false;
	        }
	    }
	
	}
	



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