C#：网络编程 - GET / HTTP 请求的网站

Question

So, we have a lab about network programming. We ain't gonna go too deep now because this is only an intro, but it's still very tricky.

Anyway... I am using the localhost (127.0.0.1) as Client and the Server is what we really have to code, as a Console App.

In the directory of the application there are 2 webpages (index.html and secondpage.html) - for testing purposes.

Part 2 of the assignment says:

The server checks upon every GET if the requested website exists in the "data system", if it exists , then it sends the following:

• Confirmation code (200)
• Number of chars the webpage has
• and bla bla bla

(Basically using FileStream, etc...)

My question is basically about this "checking"(in bold). I can manage the rest, once I get this checking/conditional statement right.

Until now that's what I have (snippet of the relevant parts):

private static void ClientHandler(object o)
    {
        TcpClient client = o as TcpClient;
        NetworkStream stream = client.GetStream();

        int i;
        Byte[] bytes = new Byte[256];

        while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
        {
            string webPage = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
            Console.WriteLine(webPage);
            
        }

    } 

PS1: ClientHandler is the method that is(as a new thread) executed when the client connects

PS2: And that Console.WriteLine was a check to see what exactly I get.

Output, using MS Edge, for http://127.0.0.1/index.html ):

---

---

GET /index.html HTTP/1.1

Host: 127.0.0.1

Connection: keep-alive

Cache-Control: max-age=0

sec-ch-ua: " Not;A Brand";v="99", "Microsoft Edge";v="91", "Chromium";v="91"

sec-ch-ua-mobile: ?0

DNT: 1 Upgrade-Insecure-Requests: 1

User-Agent: Mozilla/5.0( Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36 Edg/91.0.864.37

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng, / ;q=0.8,application/signed-exchange;v=b3;q=0.9

Sec -Fetch-Site: none

Sec-Fetch-Mode: navigate

Sec-Fetch-User: ?1

Sec-Fetch-Dest: document

Accept-Encoding: gzip, deflate, br

Accept-Language: en-GB,en;q=0.9,de;q=0.8,de-DE;q=0.7,en-US;q=0.6

---

I was thinking that if I could, for example, create a list of string will all the names of the pages I have, like a "database", get the part of that GET Line that refers to what I wrote after 127.0.0.1, in this case index.html, and then check if the list contains it.

But I don't even get this o/p per line, rather I get the first char of the first line, then the one of the second, till I get the first character of the last line, then it returns, starts getting the second char of the first line, the one of the second, till it gets all of them - in a vertical manner, you know, not in a horizontal one. Weird. I hope you guys know what I mean.

So, what is this checking and how can I please do it?

Thanks.

Answer 1

A possible solution (or idea) for your problem would be to get the whole request of your client as a string. If it contains linebreaks like your example you would grab the first line and search for the requested document/site page (for example index.html) via Regex. You could also apply the regex against the request and fetch the first result.