最近对socket相关的东西感兴趣(其实之前接触过的,研究QQ的收发数据包的时候和UDP相关)。因为这次想看看WinInet库(对socket的一层封装)的原理而接触了socket,打算直接用socket写一个http/https的访问类:
代码:
#pragma once
#include"EspString.hpp"
#pragma comment(lib,"ws2_32.lib")
#include<iostream>
class EspHttp
{
private:
unsigned int HSocket = INVALID_SOCKET;
bool IsPost = false;
bool IsHttps = false;
unsigned int ErrorCode;
unsigned short nPort;
EspString lpszScheme;//http or https
EspString lpszEntireURL;
EspString lpszHostName;//www.baidu.com
EspString lpszURLPath;// ...com/[.....]<-
EspString lpszProtocol;//Submitted/received protocol
EspString lpszAddInfo;//POST method
EspString lpszResult;//recv
EspString lpszStatus;//HTTP/1.1 200 OK HTTP/1.1 400 Bad Request
EspString lpszContent;// Manbody of the Result
bool RequestOK;//Whether is HTTP/1.1 200 OK
bool AnalyzeURL()
{
unsigned long ParsePos = 0; unsigned long TargetPos = 0;
assert(lpszEntireURL.GetBuffer() != NULL && ::IsBadStringPtrA(lpszEntireURL.GetBuffer(), -1) == false);
EspString lpszTempString;
TargetPos = lpszEntireURL.Find(":", 0);
if (TargetPos == -1)
return false;
lpszTempString = lpszEntireURL.GetLeftStr(TargetPos);
if (lpszTempString.CompareNoCase("http"))
lpszScheme = "http";
else if (lpszTempString.CompareNoCase("https"))
{
lpszScheme = "https";
IsHttps = true;
}
else
return false;
ParsePos += (lpszTempString.GetLength() + 3);
TargetPos = lpszEntireURL.Find(":", ParsePos);
if (TargetPos != -1)
{
lpszTempString = lpszEntireURL.GetMidStr(ParsePos, TargetPos - ParsePos);
if (lpszTempString.IsEmpty())return false;
lpszHostName = lpszTempString;
ParsePos += (lpszTempString.GetLength() + 1);
TargetPos = lpszEntireURL.Find("/", ParsePos);
if (TargetPos == -1)
return false;
nPort = ::strtoul(lpszEntireURL.GetMidStr(ParsePos, TargetPos - ParsePos).GetAnsiStr(), 0, 0);
}
else
{
TargetPos = lpszEntireURL.Find("/", ParsePos);
if (TargetPos == -1)
return false;
lpszTempString = lpszEntireURL.GetMidStr(ParsePos, TargetPos - ParsePos);
if (lpszTempString.IsEmpty())return false;
lpszHostName = lpszTempString;
if (IsHttps)
nPort = 443;
else
nPort = 80;
}
lpszURLPath = lpszEntireURL.GetMidStr(TargetPos, lpszEntireURL.GetLength() - TargetPos);
return true;
}
public:
EspHttp()
{
WSADATA SocketData = { 0 };
ErrorCode = ::WSAStartup(MAKEWORD(2, 2), &SocketData);
if (ErrorCode == 0)
{
HSocket = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (HSocket == INVALID_SOCKET)
ErrorCode = ::WSAGetLastError();
}
}
~EspHttp()
{
if (ErrorCode == 0)
{
if (HSocket != INVALID_SOCKET)
::closesocket(HSocket);
::WSACleanup();
}
}
unsigned int GetLastError() { return ErrorCode; }
bool ConnectTo(const char* lpszURL, bool IsPOST = false, const char* lpszAddInfo = NULL)
{
assert(lpszURL != NULL && ::IsBadStringPtrA(lpszURL, -1) == false);
lpszEntireURL = lpszURL;
if (lpszEntireURL.IsEmpty())
return false;
if (!AnalyzeURL())
return false;
SOCKADDR_IN SocketAddr = { AF_INET,::htons(nPort),*((LPIN_ADDR) * ::gethostbyname(lpszHostName.GetAnsiStr())->h_addr_list) };
if (::connect(HSocket, (LPSOCKADDR)&SocketAddr, sizeof(SOCKADDR_IN)) == SOCKET_ERROR)
{
ErrorCode = ::WSAGetLastError();
::closesocket(HSocket);
return false;
}
IsPost = IsPOST;
if (IsPost)
{
lpszProtocol.Append("POST ");
if (lpszAddInfo != NULL)
this->lpszAddInfo = lpszAddInfo;
}
else
lpszProtocol.Append("GET ");
lpszProtocol.Append(lpszURLPath.GetAnsiStr());
lpszProtocol.Append(" HTTP/1.1\r\n");
lpszProtocol.Append("Host: "); lpszProtocol.Append(lpszHostName.GetAnsiStr()); lpszProtocol.Append("\r\n");
}
void AddToProtocol(const char* lpszName, const char* lpszValue)
{
assert(lpszName != NULL && ::IsBadStringPtrA(lpszName, -1) == false);
assert(lpszValue != NULL && ::IsBadStringPtrA(lpszValue, -1) == false);
lpszProtocol.Append(lpszName);
lpszProtocol.Append(": ");
lpszProtocol.Append(lpszValue);
lpszProtocol.Append("\r\n");
}
bool SendRequest()
{
lpszProtocol.Append("\r\n");
if (IsPost)
lpszProtocol.Append(lpszAddInfo);
if (::send(HSocket, lpszProtocol.GetAnsiStr(), lpszProtocol.GetLength() + 1, 0) == SOCKET_ERROR)
{
ErrorCode = ::WSAGetLastError();
return false;
}
char* Buffer = (char*)::malloc(1025);
if (Buffer == NULL)
throw("Allocate Buffer Unsuccessfully");
unsigned long BufferSize = 0;
lpszResult.Empty();
do
{
BufferSize = ::recv(HSocket, Buffer, 1024, 0);
if (BufferSize > 0)
{
::memset(Buffer + BufferSize, 0, (1025 - BufferSize) * sizeof(char));
lpszResult.Append(Buffer);
}
else if (BufferSize == 0)
break;
else if (BufferSize == SOCKET_ERROR)
{
ErrorCode = ::WSAGetLastError();
return false;
}
} while (BufferSize != 0);
if (!lpszResult.IsEmpty())
{
unsigned long Pos1 = lpszResult.Find("\r\n");
if (Pos1 == -1)return false;
lpszStatus = lpszResult.GetLeftStr(Pos1);
unsigned long Pos2 = lpszResult.Find("\r\n\r\n");
if (Pos2 == -1)return false;
lpszProtocol = lpszResult.GetMidStr(Pos1, Pos2);
lpszContent = lpszResult.GetMidStr(Pos2+1, lpszResult.GetLength() - Pos2);
return true;
}
else
return false;
}
EspString GetResponce()
{
return lpszResult;
}
};
可以实现最简单的Get和Post请求功能,亲测成功(一些开放的和抓取到的API都能请求成功)但是我在之前是在SendRequest之后直接返回的所有数据(没有接下来那一步解析),发现这个程序它recv了两次(SendRequest部分第149行),第一次是200 OK,数据读取也正常。但是第二次就是400 Bad Request了,很迷惑。
所有输出:
HTTP/1.1 200 OK
Date: Sat, 27 Feb 2021 16:38:39 GMT
Content-Type: application/json; charset=utf-8
Content-Length: 973
Connection: keep-alive
Bili-Status-Code: 0
Bili-Trace-Id: 4f3d3a4ca5603a75
X-Cache-Webcdn: BYPASS from cn-sdjn2-cmcc-w-02
{"code":0,"message":"0","ttl":1,"data":{"mid":(隐藏),"name":"(隐藏),"sex":"(隐藏)","face":"(隐藏)","sign":"濂借倽鍑€熷姏锛岄€佹垜涓婇潚浜戙€?,"rank":10000,"level":4,"jointime":0,"moral":0,"silence":0,"birthday":"","coins":0,"fans_badge":false,"official":{"role":0,"title":"","desc":"","type":-1},"vip":{"type":0,"status":0,"theme_type":0,"label":{"path":"","text":"","label_theme":""},"avatar_subscript":0,"nickname_color":""},"pendant":{"pid":0,"name":"","image":"","expire":0,"image_enhance":"","image_enhance_frame":""},"nameplate":{"nid":0,"name":"","image":"","image_small":"","level":"","condition":""},"is_followed":false,"top_photo":"http://i0.hdslb.com/bfs/space/44873d3568bdcb3d850d234e02a19602972450f1.png","theme":{},"sys_notice":{},"live_room":{"roomStatus":0,"liveStatus":0,"url":"","title":"","cover":"","online":0,"roomid":0,"roundStatus":0,"broadcast_type":0}}}HTTP/1.1 400 Bad Request
Server: Tengine
Date: Sat, 27 Feb 2021 16:38:39 GMT
Content-Type: text/html
Content-Length: 571
Connection: close
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html>
<head><title>400 Bad Request</title></head>
<body>
<center><h1>400 Bad Request</h1></center>
Sorry for the inconvenience.<br/>
Please report this message and include the following information to us.<br/>
Thank you very much!</p>
<table>
<tr>
<td>URL:</td>
<td>http://default.bilibili.com</td>
</tr>
<tr>
<td>Server:</td>
<td>cn-sdjn2-cmcc-w-02</td>
</tr>
<tr>
<td>Date:</td>
<td>2021/02/28 00:38:39</td>
</tr>
</table>
<hr/>Powered by Tengine<hr><center>tengine</center>
</body>
</html>
↑(调用的B站用户信息获取API)
请问为什么会连着请求了两次而且第一次成功返回第二次失败,如果其他地方发现有问题也希望您指出,谢谢~
(EspString是自己写的一个字符串类,你当成CString就好......)