URL内容怎么利用C++实现获取-创新互联

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实现方法如下：

#ifndef HTTPUTIL_H
#define HTTPUTIL_H
#include 
#include 
#include  
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