這篇文章將為大家詳細講解有關URL內容怎么利用C++ 實現獲取，文章內容質量較高，因此小編分享給大家做個參考，希望大家閱讀完這篇文章后對相關知識有一定的了解。
實現方法如下：
#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測試代碼：
#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;
}補充知識：C++處理URL的方法，項目有用到，過程記錄如下
由于這塊需要轉換成unicode碼，也就是將字符串傳換成unicode碼，因此需要對輸入的字符串做處理，同時又分兩種情況，中文 非中文的處理，要區別對待，首先要對輸入的字符串進行識別：
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;
}然后要進行相應轉換
//---------------------------------------------------------------------
//函數：W2C
//功能：將16位wchar_t轉換為 8位char[2]
//參數：w_cn為待轉換的16位字符，c_cn[]為轉換后的8位字符
//備注：wchar_t的高位字節應該存儲在char數組的低位字節
//作者：xxxx
//---------------------------------------------------------------------
void W2C(wchar_t w_cn , char c_cn[]){c_cn[0] = w_cn >> 8 ;c_cn[1] = (char)w_cn ;}然后主體轉換代碼：
//-------------------------------------------------------------------
//函數：ToHex
//功能：將16位字符串轉換為十六進制字符串
//參數：待轉換的字符串，字符串長度
//返回值：轉換后的字符串
//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;
}關于URL內容怎么利用C++ 實現獲取就分享到這里了，希望以上內容可以對大家有一定的幫助，可以學到更多知識。如果覺得文章不錯，可以把它分享出去讓更多的人看到。
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