I'm making a request to a remote web server that is currently offline (on purpose).
I'd like to figure out the best way to time out the request. Basically if the request runs longer than "X" milliseconds, then exit the request and return a null
response.
Currently the web request just sits there waiting for a response.....
How would I best approach this problem?
Here's a current code snippet
public JsonpResult About(string HomePageUrl)
{
Models.Pocos.About about = null;
if (HomePageUrl.RemoteFileExists())
{
// Using the Html Agility Pack, we want to extract only the
// appropriate data from the remote page.
HtmlWeb hw = new HtmlWeb();
HtmlDocument doc = hw.Load(HomePageUrl);
HtmlNode node = doc.DocumentNode.SelectSingleNode("//div[@class='wrapper1-border']");
if (node != null)
{
about = new Models.Pocos.About { html = node.InnerHtml };
}
//todo: look into whether this else statement is necessary
else
{
about = null;
}
}
return this.Jsonp(about);
}
I had to make a small adjustment to my originally posted code
public JsonpResult About(string HomePageUrl)
{
Models.Pocos.About about = null;
// ************* CHANGE HERE - added "timeout in milliseconds" to RemoteFileExists extension method.
if (HomePageUrl.RemoteFileExists(1000))
{
// Using the Html Agility Pack, we want to extract only the
// appropriate data from the remote page.
HtmlWeb hw = new HtmlWeb();
HtmlDocument doc = hw.Load(HomePageUrl);
HtmlNode node = doc.DocumentNode.SelectSingleNode("//div[@class='wrapper1-border']");
if (node != null)
{
about = new Models.Pocos.About { html = node.InnerHtml };
}
//todo: look into whether this else statement is necessary
else
{
about = null;
}
}
return this.Jsonp(about);
}
Then I modified my RemoteFileExists
extension method to have a timeout
public static bool RemoteFileExists(this string url, int timeout)
{
try
{
//Creating the HttpWebRequest
HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
// ************ ADDED HERE
// timeout the request after x milliseconds
request.Timeout = timeout;
// ************
//Setting the Request method HEAD, you can also use GET too.
request.Method = "HEAD";
//Getting the Web Response.
HttpWebResponse response = request.GetResponse() as HttpWebResponse;
//Returns TRUE if the Status code == 200
return (response.StatusCode == HttpStatusCode.OK);
}
catch
{
//Any exception will returns false.
return false;
}
}
In this approach, if my timeout fires before RemoteFileExists
can determine the header response, then my bool
will return false.