Download file using WCF REST services

Hi,
Generally we used to download a file using a handlers and sending parameters as a querystring (lets say download.ashx). Here few cases we might need to impersonate the user also. It purely depends on environment.

Here is a sample code snippet just for reference.

if (extension.Trim() == ".pdf")
{
  context.Response.Clear();
  context.Response.ContentType = "application/pdf";                        
  context.Response.AddHeader("content-disposition", "attachment;filename=" + queryFile + ".pdf");
  context.Response.BinaryWrite(System.IO.File.ReadAllBytes(file));      
}

But instead of that we can download a file as a stream using a WCF REST service too.
Here is the code snippet for declaration in interface ..

/// <summary>
/// To fetch documents
/// </summary>
/// <param name="filePath">Represent text of filepath</param>
/// <param name="fileName">Represents text of filename</param>
/// <returns>Fetch documents</returns>
[OperationContract]
[WebGet(UriTemplate = "DownloadFile/{filePath}/{fileName}")]
Stream DownloadFile(string filePath, string fileName);

and here is the code for Implementation part.

/// <summary>
/// To fetch documents
/// </summary>
/// <param name="filePath">Represent text of filepath</param>
/// <param name="fileName">Represents text of filename</param>
/// <returns>Fetch documents</returns>
public Stream DownloadFile(string filePath, string fileName)
{
  string downloadFilePath = Path.Combine(HostingEnvironment.MapPath("~/FOLDERPATH/"), filePath + @"/" + fileName);
  WebOperationContext.Current.OutgoingResponse.ContentType = "application/octet-stream";
  return File.OpenRead(downloadFilePath);
}

Regards, Pavan N