Customized Text Document .NET HTTP Handler

Matthew So (Hong Kong)

Rate me:

4.50/5 (3 votes)

15 Sep 20022 min read

90.3K

543

Customized text document .NET HTTP handler to process text file not with standard extensions, like .aaa, .xxx.

textdochandler.zip
- TextDocHandler.cs

using System ;
using System.IO ;
using System.Web ;
using System.Text ; 

namespace Matthew.Utility
{

 public class FileHandler : IHttpHandler {


  private const int RD_BUFFER_SIZE = 4*1024 ;
  private HttpResponse Response ;
  private HttpRequest Request ;


  // State for Async read 	
  public class StateObject {
 	public byte[] bs ;
 	public FileStream fs ;
  }

  public void ProcessRequest(HttpContext ctx) {

	Response = ctx.Response ;
	Request = ctx.Request ;

	String Filename = Request.FilePath ;

	if ( Filename != null ) {

		
		Filename = Request.MapPath(Filename) ;
		FileStream fs = null ;

		try {
			fs = File.Open(Filename , FileMode.Open, FileAccess.Read, FileShare.Read) ;
		}
		catch (  FileNotFoundException  ) {
			Response.Write("<html><body><h2>File <i>" + Request.FilePath + "</i> not exists!</h2></body></html>" ) ;
			return ;
		}

		StateObject stateObject = new StateObject() ;

		stateObject.fs = fs ;
		stateObject.bs = new byte[RD_BUFFER_SIZE] ;
		
		//  Set the content type as the browser need to know how to display the content bases on its type
		Response.ContentType = "Text/plain" ;

		// Begin Async file read
 		fs.BeginRead( stateObject.bs, 0, RD_BUFFER_SIZE,  new AsyncCallback(this.ReadCallback), stateObject );
			
	}	
  } // void ProcessRequest(HttpContext ctx)

	
  public bool IsReusable { get { return true ; } } 	


  public void ReadCallback(IAsyncResult asyncResult)  {
	
	StateObject stateObject = (StateObject) asyncResult.AsyncState;

	FileStream fs = stateObject.fs;//(Stream) asyncResult.AsyncObject;

	int bytesRead = fs.EndRead(asyncResult);

	// Stream only return zero (0) at the end of the stream
	if ( bytesRead != 0 )  {  
		Response.BinaryWrite(stateObject.bs) ;
  		fs.BeginRead( stateObject.bs, 0, RD_BUFFER_SIZE, 
			new AsyncCallback(this.ReadCallback), stateObject );		
	}
	else {
   		fs.Close() ;
	}
	
  }


 } // Class
} // namespace

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

Written By

Matthew So (Hong Kong)

Founder Software Force

Hong Kong

I am always interested in finding innovative ways for building better applications and founded a technology company since 2003. Welcome to exchange any idea with you and if I am not too busy before deadline of projects, I will reply your emails. Also, if you willing to pay for consulting works and customized software development, you can leave me message.

Customized Text Document .NET HTTP Handler

License

Comments and Discussions