C＃：如何使用套接字执行HTTP请求？

Question

我想用套接字做一个HTTP request。我的代码如下：

using System; 
using System.Net; 
using System.Net.Sockets; 
using System.Text; 
class test 
{ 
    public static void Main(String[] args) 
    { 
     string hostName = "127.0.0.1"; 
     int hostPort = 9887; 
     int response = 0; 

     IPAddress host = IPAddress.Parse(hostName); 
     IPEndPoint hostep = new IPEndPoint(host, hostPort); 
     Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); 

     sock.Connect(hostep); 

     string request_url = "http://127.0.0.1/register?id=application/vnd-fullphat.test&title=My%20Test%20App"; 
     response = sock.Send(Encoding.UTF8.GetBytes(request_url)); 
     response = sock.Send(Encoding.UTF8.GetBytes("\r\n")); 

     bytes = sock.Receive(bytesReceived, bytesReceived.Length, 0); 
     page = page + Encoding.ASCII.GetString(bytesReceived, 0, bytes); 
     Console.WriteLine(page); 
     sock.Close(); 
    } 
} 

现在，当我执行上面的代码没有任何反应，而当我在浏览器中输入我的request_url我从咆哮的通知说，Application Registered，我从浏览器中得到的响应是

SNP/2.0/0/OK/556 

我从我的代码得到的回复是SNP/3.0/107/BadPacket。

那么，我的代码有什么问题。

Snarl Request format specification

Answer 1

您必须在年底内容长度和双新线指示头结束。

var request = "GET /register?id=application/vnd-fullphat.test&title=My%20Test%20App HTTP/1.1\r\n" + 
    "Host: 127.0.0.1\r\n" + 
    "Content-Length: 0\r\n" + 
    "\r\n"; 

HTTP 1.1规范可以在这里找到：http://www.w3.org/Protocols/rfc2616/rfc2616.html

Answer 2

您的要求是不正确的。据wikipedia, a HTTP Get request有看起来像：

string request = "GET /register?id=application/vnd-fullphat.test&title=My%20Test%20App HTTP/1.1\r\nHost: 127.0.0.1\r\n"; 

Answer 3

我一无所知SNP。你的代码在接收部分有点混乱。我使用下面的示例发送和读取HTTP GET请求的服务器响应。首先让我们看看请求，然后检查响应。

HTTP GET请求：

GET/HTTP/1.1 
Host: 127.0.0.1 
Connection: keep-alive 
Accept: text/html 
User-Agent: CSharpTests 

string - "GET/HTTP/1.1\r\nHost: 127.0.0.1\r\nConnection: keep-alive\r\nAccept: text/html\r\nUser-Agent: CSharpTests\r\n\r\n" 

服务器的HTTP响应头：

HTTP/1.1 200 OK 
Date: Sun, 07 Jul 2013 17:13:10 GMT 
Server: Apache/2.4.4 (Win32) OpenSSL/0.9.8y PHP/5.4.16 
Last-Modified: Sat, 30 Mar 2013 11:28:59 GMT 
ETag: \"ca-4d922b19fd4c0\" 
Accept-Ranges: bytes 
Content-Length: 202 
Keep-Alive: timeout=5, max=100 
Connection: Keep-Alive 
Content-Type: text/html 

string - "HTTP/1.1 200 OK\r\nDate: Sun, 07 Jul 2013 17:13:10 GMT\r\nServer: Apache/2.4.4 (Win32) OpenSSL/0.9.8y PHP/5.4.16\r\nLast-Modified: Sat, 30 Mar 2013 11:28:59 GMT\r\nETag: \"ca-4d922b19fd4c0\"\r\nAccept-Ranges: bytes\r\nContent-Length: 202\r\nKeep-Alive: timeout=5, max=100\r\nConnection: Keep-Alive\r\nContent-Type: text/html\r\n\r\n" 

我有意中省略了服务器响应的主体，因为我们已经知道它到底是202个字节，如指定通过响应头中的Content-Length。

查看HTTP规范将显示HTTP头以空行（“\ r \ n \ r \ n”）结尾。所以我们只需要搜索它。

让我们看看一些实际的代码。假定一个System.Net.Sockets.Socket类型的变量套接字。

socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); 
socket.Connect("127.0.0.1", 80); 
string GETrequest = "GET/HTTP/1.1\r\nHost: 127.0.0.1\r\nConnection: keep-alive\r\nAccept: text/html\r\nUser-Agent: CSharpTests\r\n\r\n"; 
socket.Send(Encoding.ASCII.GetBytes(GETrequest)); 

我们已经发送请求到服务器，让我们接收并正确解析响应。

bool flag = true; // just so we know we are still reading 
string headerString = ""; // to store header information 
int contentLength = 0; // the body length 
byte[] bodyBuff = new byte[0]; // to later hold the body content 
while (flag) 
{ 
// read the header byte by byte, until \r\n\r\n 
byte[] buffer = new byte[1]; 
socket.Receive(buffer, 0, 1, 0); 
headerString += Encoding.ASCII.GetString(buffer); 
if (headerString.Contains("\r\n\r\n")) 
{ 
    // header is received, parsing content length 
    // I use regular expressions, but any other method you can think of is ok 
    Regex reg = new Regex("\\\r\nContent-Length: (.*?)\\\r\n"); 
    Match m = reg.Match(headerString); 
    contentLength = int.Parse(m.Groups[1].ToString()); 
    flag = false; 
    // read the body 
    bodyBuff = new byte[contentLength]; 
    socket.Receive(bodyBuff, 0, contentLength, 0); 
} 
} 
Console.WriteLine("Server Response :"); 
string body = Encoding.ASCII.GetString(bodyBuff); 
Console.WriteLine(body); 
socket.Close(); 

这可能是C＃这样做最坏的方法，有吨的类来处理HTTP请求和响应在.NET中，但仍，如果你需要它，它的工作原理。

Answer 4

HTTP请求的最低要求是 “GET/HTTP/1.0 \ r \ n \ r \ n”（如果删除允许主机）。 但是在SNARL中，您必须输入内容长度（我最常听到的）。

所以，

 Socket sck = new Socket(AddressFamily.InterNetwork,SocketType.Stream, ProtocolType.Tcp); 

     sck.Connect(ip, port); 
     sck.Send(Encoding.UTF8.GetBytes("THE HTTP REQUEST HEADER")); 
     Console.WriteLine("SENT"); 
     string message = null; 
     byte[] bytesStored = new byte[ReceiveBufferSize]; 
     int k1 = sck.Receive(bytesStored); 
     for (int i = 0; i < k1; i++) 
     { 
      message = message + Convert.ToChar(bytesStored[i]).ToString(); 
     } 
     Console.WriteLine(message); // PRINT THE RESPONSE 

编辑：我对以前的穷人答案深感抱歉。它没有形成，我添加了答案的主要思想/解决方案（没有简单的信息）。另外，我添加了源代码。

我在几个网站上测试过，效果很好。如果它不起作用，那么你应该通过添加更多的头部来解决它（最有可能的解决方案）。