这篇文章将为大家详细讲解有关URL内容怎么利用C++ 实现获取,文章内容质量较高,因此小编分享给大家做个参考,希望大家阅读完这篇文章后对相关知识有一定的了解。
实现方法如下:
#ifndef HTTPUTIL_H #define HTTPUTIL_H #include <windows.h> #include <string> #include <stdio.h> using std::string; #pragma comment(lib,"ws2_32.lib") void mParseUrl(char *mUrl, string &serverName, string &filepath, string &filename); SOCKET connectToServer(char *szServerName, WORD portNum); int getHeaderLength(char *content); char *readUrl2(char *szUrl, long &bytesReturnedOut, char **headerOut); char *sendRequest(char szUrl[]) { WSADATA wsaData; //char szUrl[] = "http://api.m.taobao.com/rest/api3.do?api=mtop.common.getTimestamp"; long fileSize; char *memBuffer, *headerBuffer; memBuffer = headerBuffer = nullptr; if (WSAStartup(0x101, &wsaData) != 0) return nullptr; memBuffer = readUrl2(szUrl, fileSize, &headerBuffer); printf("returned from readUrl\n"); printf("data returned:\n%s", memBuffer); if (fileSize != 0) { //delete (memBuffer); delete (headerBuffer); } WSACleanup(); return memBuffer; } void mParseUrl(char *mUrl, string &serverName, string &filepath, string &filename) { string::size_type n; string url = mUrl; if (url.substr(0, 7) == "http://") url.erase(0, 7); if (url.substr(0, 8) == "https://") url.erase(0, 8); n = url.find('/'); if (n != string::npos) { serverName = url.substr(0, n); filepath = url.substr(n); n = filepath.rfind('/'); filename = filepath.substr(n + 1); } else { serverName = url; filepath = "/"; filename = ""; } } SOCKET connectToServer(char *szServerName, WORD portNum) { struct hostent *hp; unsigned int addr; struct sockaddr_in server; SOCKET conn; conn = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (conn == INVALID_SOCKET) return NULL; if (inet_addr(szServerName) == INADDR_NONE) { hp = gethostbyname(szServerName); } else { addr = inet_addr(szServerName); hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET); } if (hp == nullptr) { closesocket(conn); return NULL; } server.sin_addr.s_addr = *((unsigned long *)hp->h_addr); server.sin_family = AF_INET; server.sin_port = htons(portNum); if (connect(conn, (struct sockaddr *)&server, sizeof(server))) { closesocket(conn); return NULL; } return conn; } int getHeaderLength(char *content) { const char *srchStr1 = "\r\n\r\n", *srchStr2 = "\n\r\n\r"; char *findPos; int ofset = -1; findPos = strstr(content, srchStr1); if (findPos != nullptr) { ofset = findPos - content; ofset += strlen(srchStr1); } else { findPos = strstr(content, srchStr2); if (findPos != nullptr) { ofset = findPos - content; ofset += strlen(srchStr2); } } return ofset; } char *readUrl2(char *szUrl, long &bytesReturnedOut, char **headerOut) { const int bufSize = 512; char readBuffer[bufSize], sendBuffer[bufSize], tmpBuffer[bufSize]; char *tmpResult = nullptr, *result; SOCKET conn; string server, filepath, filename; long totalBytesRead, thisReadSize, headerLen; mParseUrl(szUrl, server, filepath, filename); / step 1, connect // conn = connectToServer((char *)server.c_str(), 80); / step 2, send GET request / sprintf(tmpBuffer, "GET %s HTTP/1.0", filepath.c_str()); strcpy(sendBuffer, tmpBuffer); strcat(sendBuffer, "\r\n"); sprintf(tmpBuffer, "Host: %s", server.c_str()); strcat(sendBuffer, tmpBuffer); strcat(sendBuffer, "\r\n"); strcat(sendBuffer, "\r\n"); send(conn, sendBuffer, strlen(sendBuffer), 0); // SetWindowText(edit3Hwnd, sendBuffer); printf("Buffer being sent:\n%s", sendBuffer); / step 3 - get received bytes // Receive until the peer closes the connection totalBytesRead = 0; while (1) { memset(readBuffer, 0, bufSize); thisReadSize = recv (conn, readBuffer, bufSize, 0); if ( thisReadSize <= 0 ) break; tmpResult = (char *)realloc(tmpResult, thisReadSize + totalBytesRead); memcpy(tmpResult + totalBytesRead, readBuffer, thisReadSize); totalBytesRead += thisReadSize; } headerLen = getHeaderLength(tmpResult); long contenLen = totalBytesRead - headerLen; result = new char[contenLen + 1]; memcpy(result, tmpResult + headerLen, contenLen); result[contenLen] = 0x0; char *myTmp; myTmp = new char[headerLen + 1]; strncpy(myTmp, tmpResult, headerLen); myTmp[headerLen] = NULL; delete (tmpResult); *headerOut = myTmp; bytesReturnedOut = contenLen; closesocket(conn); return (result); } #endif // HTTPUTIL_H
测试代码:
#include <string> #include <stdio.h> #include "HttpUtil.h" #include <iostream> using std::string; using namespace std; int main() { char *resData = sendRequest("http://api.m.taobao.com/rest/api3.do?api=mtop.common.getTimestamp"); string str = resData; cout << endl << str << endl; delete resData; return 0; }
补充知识:C++处理URL的方法,项目有用到,过程记录如下
由于这块需要转换成unicode码,也就是将字符串传换成unicode码,因此需要对输入的字符串做处理,同时又分两种情况,中文 非中文的处理,要区别对待,首先要对输入的字符串进行识别:
int 是不是中文(char *str) { char ch; while (1) { ch = *str++; if (ch == 0) { break; } if (ch&0x80) { if (*str & 0x80) { return true; } } else { return false; } } return 0; }
然后要进行相应转换
//--------------------------------------------------------------------- //函数:W2C //功能:将16位wchar_t转换为 8位char[2] //参数:w_cn为待转换的16位字符,c_cn[]为转换后的8位字符 //备注:wchar_t的高位字节应该存储在char数组的低位字节 //作者:xxxx //--------------------------------------------------------------------- void W2C(wchar_t w_cn , char c_cn[]){c_cn[0] = w_cn >> 8 ;c_cn[1] = (char)w_cn ;}
然后主体转换代码:
//------------------------------------------------------------------- //函数:ToHex //功能:将16位字符串转换为十六进制字符串 //参数:待转换的字符串,字符串长度 //返回值:转换后的字符串 //作者:xxxx //------------------------------------------------------------------- CString ToHex(CString Data, long nDataLength) { CString sResult; for (long nLoop=0; nLoop<nDataLength; nLoop++) { wchar_t ch = Data.GetAt(nLoop); CHAR buff[MAX_PATH] = {0}; LPCWSTR str = &ch; WideCharToMultiByte(CP_ACP, 0, (LPCWSTR)str, -1, buff, MAX_PATH, 0, 0); if (IncludeChinese(buff)) { char c_cn[2]={'0'}; W2C(ch,c_cn); static const char *hex = "0123456789ABCDEF"; for(int i=0;i<2;i++) { unsigned char chHexA = hex[((unsigned char)(c_cn[i]) >> 4) & 0x0f]; unsigned char chHexB = hex[(unsigned char)(c_cn[i]) & 0x0f]; sResult += (char)chHexA; sResult += (char)chHexB; } } else { sResult += ch; } } return sResult; }
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