What Difference Is There Between Webclient and Httpwebrequest Classes in .Net

What difference is there between WebClient and HTTPWebRequest classes in .NET?

WebClient is a higher-level abstraction built on top of HttpWebRequest to simplify the most common tasks. For instance, if you want to get the content out of an HttpWebResponse, you have to read from the response stream:

var http = (HttpWebRequest)WebRequest.Create("http://example.com");
var response = http.GetResponse();

var stream = response.GetResponseStream();
var sr = new StreamReader(stream);
var content = sr.ReadToEnd();

With WebClient, you just do DownloadString:

var client = new WebClient();
var content = client.DownloadString("http://example.com");

Note: I left out the using statements from both examples for brevity. You should definitely take care to dispose your web request objects properly.

In general, WebClient is good for quick and dirty simple requests and HttpWebRequest is good for when you need more control over the entire request.

WebClient vs. HttpWebRequest/HttpWebResponse

Using HttpWebRequest gives you more control on the request. You can set cookies, headers, protocol, etc... In the response, you can also retrieve the cookies and headers

Is HttpWebRequest or Webclient faster

WebClient is just a wrapper around HttpWebRequest. Using WebClient is potentially slightly (on the order of a few milliseconds) slower than using HttpWebRequest directly. But that "inefficiency" comes with huge benefits: it requires less code, is easier to use, and you're less likely to make a mistake when using it. Consider, for example, retrieving the text of a Web page using WebClient:

var client = new WebClient();
var text = client.DownloadString("http://example.com/page.html");

Contrast that to HttpWebRequest:

string text;
var request = (HttpWebRequest)WebRequest.Create("http://example.com/page.html");
using (var response = request.GetResponse())
{
    using (var reader = new StreamReader(response.GetResponseStream()))
    {
        text = reader.ReadToEnd();
    }
}

Things get really interesting if you want to download and save to file. With WebClient, it's a simple matter of calling DownloadFile. With HttpWebRequest, you have to create a reading loop, etc. The number of ways you can make a mistake with HttpWebRequest is truly astounding. I know 'cause I've made a lot of them.

Now consider downloading two different pages. With WebClient you can write:

var client = new WebClient();
var page1 = client.DownloadString(page1Url);
var page2 = client.DownloadString(page2Url);

Done. With HttpWebRequest, you'd have to duplicate the code above, or wrap that code in a method. But if you're going to wrap it in a method, then why not just use WebClient, which already does it for you?

When you consider that a request to a fast Web site will probably take on the order of 100 to 500 milliseconds, the few milliseconds' overhead that WebClient adds will amount to at most single-digit percentage of the total time.

Use WebClient for simple things. Only use HttpWebRequest if you require the additional low-level control that it offers. Speed considerations among the two are irrelevant.

.NET: WebBrowser, WebClient, WebRequest, HTTPWebRequest... ARGH!

WebBrowser is actually in the System.Windows.Forms namespace and is a visual control that you can add to a form. It is primarily a wrapper around the Internet Explorer browser (MSHTML). It allows you to easily display and interact programmatically with a web page. You call the Navigate method passing a web URL, wait for it to complete downloading and display and then interact with the page using the object model it provides.

HttpWebRequest is a concrete class that allows you to request in code any sort of file over HTTP. You usually receive it as a stream of bytes. What you do with it after that is up to your application.

HttpWebResponse allows you to process the response from a web server that was previously requested using HttpWebRequest.

WebRequest and WebResponse are the abstract base classes that the HttpWebRequest and HttpWebResponse inherit from. You can't create these directly. Other classes that inherit from these include Ftp and File classes.

WebClient I have always seen as a nice helper class that provides simpler ways to, for example, download or upload a file from a web url. (eg DownloadFile and DownloadString methods). I have heard that it actually uses HttpWebRequest / HttpWebResponse behind the scenes for certain methods.

If you need more fine grained control over web requests and responses, HttpWebRequest / HttpWebResponse are probably the way to go. Otherwise WebClient is generally simpler and will do the job.

Equivalent of .NET's WebClient and HttpWebRequest in Java?

HttpURLConnection is Java's equivalent of HttpWebRequest.

URL iurl = new URL(url);
HttpURLConnection uc = (HttpURLConnection)iurl.openConnection();
uc.connect();
if (uc.getContentType().equalsIgnoreCase("image/jpeg"))
{
  result = true;
}

Using .NET to Post a file to Server HttpWebRequest or WebClient

First, use something like fiddler and inspect the requests and responses to see what differs between curl and System.Net.WebClient.

Also, you can try (although inspecting with the debugging proxy should allow you to pinpoint the difference):

Use the credential cache to set your credentials for basic authentication:

var cc= new CredentialCache();
cc.Add(new Uri(url),
                  "Basic", 
                  new NetworkCredential("USERNAME", "PASSWORD"));
wc.Credentials = cc;

Set a user agent header:

string _UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)";
wc.Headers.Add(HttpRequestHeader.UserAgent, _UserAgent);

Change the protocol version on the WebRequest:

reqeust.KeepAlive = false;
request.ProtocolVersion=HttpVersion.Version10;

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