CODEWITHSUNDEEP
c#.nethttpwebresponse
Sameet
Sameet

Reputation: 2211

When to call WebResponse.Close()

WebResponse response;
try
{                
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
 request.Timeout = 20000;
 response = request.GetResponse();

 request = (HttpWebRequest)WebRequest.Create(url2);
 response = request.GetResponse();
}
catch(Exception ex)
{
 //do something
}              
finally
{
}

where should response.Close() be called?

Upvotes: 15

Views: 13515

Answers (4)

John Saunders
John Saunders

Reputation: 161783

None of the above. You should be using a using block:

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Timeout = 20000;
using (WebResponse response = request.GetResponse())
{
    using (var stream = response.GetResponseStream())
    {
        using (var reader = new StreamReader(stream))
        {
            var result = reader.ReadToEnd();
            // Do something with result
        }
    }
}

A using block will ensure that the Dispose method is called, whether or not there is an exception. Dispose will do the same thing as Close.

using (var d = new DisposableClass()){code;}

is equivalent to:

DisposableClass d = null;
try
{
    d = new DisposableClass();
    code;
}
finally
{
    if (d != null)
        ((IDisposable)d).Dispose();
}

Upvotes: 26

Eamon Nerbonne
Eamon Nerbonne

Reputation: 48066

Note that nested using blocks don't need curly braces, improving readability. So John Saunder's code could be written:

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Timeout = 20000;
using (WebResponse response = request.GetResponse())
using (var stream = response.GetResponseStream())
using (var reader = new StreamReader(stream))
{
    var result = reader.ReadToEnd();
    // Do something with result
}

VS.NET understands that such nested blocks don't need indenting. Note btw that if you know the encoding of the response or are going to ignore it anyhow, WebClient provides a simpler API - missing header information, so Header-based (transfer/text) encoding detection becomes impossible, but otherwise it works fine.

Upvotes: 0

Ramesh
Ramesh

Reputation: 13266

I would suggest the below

        try
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.google.com");
            request.Timeout = 20000;
            using (var response = request.GetResponse())
            {
                //Do something with response.
            }


            request = (HttpWebRequest)WebRequest.Create("http://www.bing.com");
            using (var response = request.GetResponse())
            {
                //Do somehing with response
            }
        }
        catch (Exception ex)
        {
            //do something
        }
        finally
        {
        }

Upvotes: -1

marco0009
marco0009

Reputation: 163

Put it in the finally block. As per MSDN:

The finally block is useful for cleaning up any resources allocated in the try block as well as running any code that must execute even if there is an exception. Control is always passed to the finally block regardless of how the try block exits.

Upvotes: 1

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