Home/ Questions/Q 397215
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-12T16:37:42+00:00

I’ve encountered an issue with HttpWebRequest that if the URI is over 2048 characters

  • 0

I’ve encountered an issue with HttpWebRequest that if the URI is over 2048 characters long the request fails and returns a 404 error even though the server is perfectly capable of servicing a request with a URI that long. I know this since the same URI that causes an error if submitted via HttpWebRequest works fine when pasted directly into a browser address bar.

My current workaround is to allow users to set a compatability flag to say that it’s safe to send the parameters as a POST request instead in the case where the URI would be too long but this is not ideal since the protocol I’m using is RESTful and GET should be used for queries. Plus there is no guarentee that other implementors of the protocol will accept POSTed queries

Is there another class in .Net that has equivalent functionality to HttpWebRequest that doesn’t suffer from the URI length limit that I could use?
I’m aware of WebClient but I don’t really want to use that as I need to be able to fully control the HTTP Headers which WebClient restricts the ability to do.

Edit

Because Shoban asked for it:

http://localhost/BBCDemo/sparql/?query=PREFIX+rdf%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E%0D%0APREFIX+rdfs%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E%0D%0APREFIX+xsd%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F2001%2FXMLSchema%23%3E%0D%0APREFIX+skos%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F2004%2F02%2Fskos%2Fcore%23%3E%0D%0APREFIX+dc%3A+%3Chttp%3A%2F%2Fpurl.org%2Fdc%2Felements%2F1.1%2F%3E%0D%0APREFIX+po%3A+%3Chttp%3A%2F%2Fpurl.org%2Fontology%2Fpo%2F%3E%0D%0APREFIX+timeline%3A+%3Chttp%3A%2F%2Fpurl.org%2FNET%2Fc4dm%2Ftimeline.owl%23%3E%0D%0ASELECT+*+WHERE+{%0D%0A++++%3Chttp%3A%2F%2Fwww.bbc.co.uk%2Fprogrammes%2Fb00n4d6y%23programme%3E+dc%3Atitle+%3Ftitle+.%0D%0A++++%3Chttp%3A%2F%2Fwww.bbc.co.uk%2Fprogrammes%2Fb00n4d6y%23programme%3E+po%3Ashort_synopsis+%3Fsynopsis-short+.%0D%0A++++%3Chttp%3A%2F%2Fwww.bbc.co.uk%2Fprogrammes%2Fb00n4d6y%23programme%3E+po%3Amedium_synopsis+%3Fsynopsis-med+.%0D%0A++++%3Chttp%3A%2F%2Fwww.bbc.co.uk%2Fprogrammes%2Fb00n4d6y%23programme%3E+po%3Along_synopsis+%3Fsynopsis-long+.%0D%0A++++%3Chttp%3A%2F%2Fwww.bbc.co.uk%2Fprogrammes%2Fb00n4d6y%23programme%3E+po%3Amasterbrand+%3Fchannel+.%0D%0A++++%3Chttp%3A%2F%2Fwww.bbc.co.uk%2Fprogrammes%2Fb00n4d6y%23programme%3E+po%3Agenre+%3Fgenre+.%0D%0A++++%3Fchannel+dc%3Atitle+%3Fchanneltitle+.%0D%0A++++OPTIONAL+{%0D%0A++++++++%3Chttp%3A%2F%2Fwww.bbc.co.uk%2Fprogrammes%2Fb00n4d6y%23programme%3E+po%3Abrand+%3Fbrand+.%0D%0A++++++++%3Fbrand+dc%3Atitle+%3Fbrandtitle+.%0D%0A++++}%0D%0A++++OPTIONAL+{%0D%0A++++++++%3Chttp%3A%2F%2Fwww.bbc.co.uk%2Fprogrammes%2Fb00n4d6y%23programme%3E+po%3Aversion+%3Fver+.%0D%0A++++++++%3Fver+po%3Atime+%3Finterval+.%0D%0A++++++++%3Finterval+timeline%3Astart+%3Fstart+.%0D%0A++++++++%3Finterval+timeline%3Aend+%3Fend+.%0D%0A++++}%0D%0A}&default-graph-uri=&timeout=30000

Which is the following encoded onto the querystring:

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX po: <http://purl.org/ontology/po/>
PREFIX timeline: <http://purl.org/NET/c4dm/timeline.owl#>
SELECT * WHERE {
  <http://www.bbc.co.uk/programmes/b00n4d6y#programme> dc:title ?title .
  <http://www.bbc.co.uk/programmes/b00n4d6y#programme> po:short_synopsis ?synopsis-short .
  <http://www.bbc.co.uk/programmes/b00n4d6y#programme> po:medium_synopsis ?synopsis-med .
  <http://www.bbc.co.uk/programmes/b00n4d6y#programme> po:long_synopsis ?synopsis-long .
  <http://www.bbc.co.uk/programmes/b00n4d6y#programme> po:masterbrand ?channel .
  <http://www.bbc.co.uk/programmes/b00n4d6y#programme> po:genre ?genre .
  ?channel dc:title ?channeltitle .
  OPTIONAL {
    <http://www.bbc.co.uk/programmes/b00n4d6y#programme> po:brand ?brand .
    ?brand dc:title ?brandtitle .
  }
  OPTIONAL {
    <http://www.bbc.co.uk/programmes/b00n4d6y#programme> po:version ?ver .
    ?ver po:time ?interval .
    ?interval timeline:start ?start .
    ?interval timeline:end ?end .
  }

}

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    the protocol I’m using is RESTful and GET should be used for queries.

    There’s no reason POST can’t also be used for queries; for really long request data you have to, as very-long-URIs aren’t globally supported, and have never been. This is one area where HTTP does not live up to the REST ideal.

    The reason POST generally isn’t used on a plain-HTML level is to stop the browser prompting for reloads, and promote eg. bookmarking. But for HttpWebRequest you don’t have either of those concerns, so go ahead and POST it. Web applications should use a parameter or a URI path part to distinguish write requests from queries, not merely the request method. (Of course a write request from a GET method should still be denied.)

    • 0