How do I check entered URL is valid or not

Question

Hi,

I have requirement to validate URL i.e. If user put invalid URL then application should show generic error page.

For ex: when user enter URL in browser like ie8

correct URl is: www.abc.com/hr/test.aspx (then test page should display)

if user puts: www.abc.com/hr/xyz (with extension or without extension) then application should redirect to generic error page.

I am using asp.net 4.0 and my application have multiple folders like admin/user etc and each folder have multiple web pages.
Please suggest how can I achieve this functionality.

Thanks

Abhishek Jain · Answer

Try this: string url; //Set URL in the string. if (!url.Contains("http://")) { url = "http://" + url; } try { var request = WebRequest.Create(url) as HttpWebRequest; request.Method = "HEAD"; using (var response = (HttpWebResponse)request.GetResponse()) { return response.StatusCode == HttpStatusCode.OK; } } catch { return false; } Regards AJ

Jignesh Trivedi · Answer

hi, Not sure why your code is hangeup... with the help of HttpContext.Current.Request.Url you can find out current requested url. In begin request you can check this url and vali it... void Application_BeginRequest(Object source, EventArgs e) { var url = HttpContext.Current.Request.Url.AbsoluteUri; // validate thi surl using Regex and re found faulty then redirect... it } hope this will help you.

Areeb Quazi · Answer

Hi Abhishek, I already added customError in web.config. but when user add URL like http://www.abc.com/test.aspx/xyz in this case it's not hitting filenotfound.aspx. Note: http://www.abc.com/test.aspx is valid URL. I tryied secound solution given by you in global.aspx application_authenticateRequest and application_beginRequest also. but application will hanged. after using (var response....) line cursor goes to application_authenticateRequest and then using (var response....) line till application hanges Please suggest what else I need to do.

Abhishek Jain · Answer

You can check it in the Global events in Global.asax file, like BeginRequest Event. One more way is to add entry for this in Web.Config; Here we are setting if the Page is not found, it means that if the URL is wrong then Redirect the user on Error Page FilenotFound.aspx. Regards AJ

Iftikar Hussain · Answer

are you reading this url value from a textbox in your application or just want to check directly in browser? Regards, Iftikar

Areeb Quazi · Answer

Since URL is wrong then on which place can I add this code.

Iftikar Hussain · Answer

Hi, Try like this private void ValidateUrl() { string url = TextBox1.Text; bool isValid = Regex.IsMatch(url, @"(http(s)?://)?([\w-])+\.(aspx)$"); if( isValid) { //do your staff } else { //redirect to error page } } Regards, Iftikar

How do I check entered URL is valid or not

Answers (7)