上一篇链接：/hfuu1504011020/article/details/88785448
上一篇中说到Unicode转utf8格式的过程，其中谈及到http以及json数据的解析，json解析其实也没啥说的，网上一大推，后面大概介绍下使用，本文着重介绍下c++客户端实现的http连接服务端并返回json数据的过程。
（重点）这里http的连接以及获取json数据过程使用的是多字节编码实现的，直接可以将其转为utf8编码存入mysql中。之前我因为使用的是Unicode编码，在本文代码的基础上再加入上一篇的编码转换也是可以实现Unicode转utf8格式过程。
我们看下http头文件所包含的参数以及函数
HttpClient.h#ifndef HTTPCLIENT_H#define HTTPCLIENT_H#include <afxinet.h>#include <string>using namespace std;#define IE_AGENT _T("Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)")// 操作成功#define SUCCESS 0// 操作失败#define FAILURE 1// 操作超时 #define OUTTIME 2class CHttpClient{public:CHttpClient(LPCTSTR strAgent = IE_AGENT);virtual ~CHttpClient(void);/*static wchar_t* ANSIToUnicode(const char* str);static char* UnicodeToANSI(const wchar_t* str);static char* UnicodeToUTF8(const wchar_t* str);*/ //在下面的ExecuteRequest函数中处理了多字节转utf8的方法，不需要再使用这三个函数，这里注释 // 的三句转码总觉得在使用时有问题，代码我一并贴出,供大家查找问题int HttpGet(LPCTSTR strUrl, LPCTSTR strPostData, string &strResponse);int HttpPost(LPCTSTR strUrl, LPCTSTR strPostData, string &strResponse);private:int ExecuteRequest(LPCTSTR strMethod, LPCTSTR strUrl, LPCTSTR strPostData, string &strResponse);void Clear();private:CInternetSession *m_pSession;CHttpConnection *m_pConnection;CHttpFile *m_pFile;};#endif // HTTPCLIENT_H
以上是http实现的头文件，以下为.cpp中代码实现过程，内容有点多，若只是使用的话粘贴复制即可
// HttpClient.cpp#include "StdAfx.h"#include "HttpClient.h"#define BUFFER_SIZE1024#define NORMAL_CONNECT INTERNET_FLAG_KEEP_CONNECTION#define SECURE_CONNECT NORMAL_CONNECT | INTERNET_FLAG_SECURE#define NORMAL_REQUEST INTERNET_FLAG_RELOAD | INTERNET_FLAG_DONT_CACHE #define SECURE_REQUEST NORMAL_REQUEST | INTERNET_FLAG_SECURE | INTERNET_FLAG_IGNORE_CERT_CN_INVALIDCHttpClient::CHttpClient(LPCTSTR strAgent){m_pSession = new CInternetSession(strAgent);m_pConnection = NULL;m_pFile = NULL;}CHttpClient::~CHttpClient(void){Clear();if(NULL != m_pSession){m_pSession->Close();delete m_pSession;m_pSession = NULL;}}void CHttpClient::Clear(){if(NULL != m_pFile){m_pFile->Close();delete m_pFile;m_pFile = NULL;}if(NULL != m_pConnection){m_pConnection->Close();delete m_pConnection;m_pConnection = NULL;}}int CHttpClient::ExecuteRequest(LPCTSTR strMethod, LPCTSTR strUrl, LPCTSTR strPostData, string &strResponse){DWORD dwFlags;DWORD dwStatus = 0;DWORD dwStatusLen = sizeof(dwStatus);CString strLine;CString strServer;CString strObject;DWORD dwServiceType;INTERNET_PORT nPort;strResponse = "";AfxParseURL(strUrl, dwServiceType, strServer, strObject, nPort);try {if (dwServiceType == AFX_INET_SERVICE_HTTP){m_pConnection = m_pSession->GetHttpConnection(strServer,NORMAL_CONNECT,nPort);}else{m_pConnection = m_pSession->GetHttpConnection(strServer, INTERNET_FLAG_SECURE, nPort,NULL, NULL);}if(m_pConnection){if (dwServiceType == AFX_INET_SERVICE_HTTP){m_pFile = m_pConnection->OpenRequest(strMethod, strObject, NULL, 1, NULL, NULL, NORMAL_REQUEST);}else{m_pFile = (CHttpFile*)m_pConnection->OpenRequest(CHttpConnection::HTTP_VERB_POST, strObject, NULL, 1,NULL, NULL,INTERNET_FLAG_SECURE |INTERNET_FLAG_EXISTING_CONNECT |INTERNET_FLAG_RELOAD |INTERNET_FLAG_NO_CACHE_WRITE |INTERNET_FLAG_IGNORE_CERT_DATE_INVALID |INTERNET_FLAG_IGNORE_CERT_CN_INVALID);//get web server optionm_pFile->QueryOption(INTERNET_OPTION_SECURITY_FLAGS, dwFlags);dwFlags |= SECURITY_FLAG_IGNORE_UNKNOWN_CA;//set web server optionm_pFile->SetOption(INTERNET_OPTION_SECURITY_FLAGS, dwFlags);}m_pFile->AddRequestHeaders("Accept: *,*/*");m_pFile->AddRequestHeaders("Accept-Language: zh-cn");m_pFile->AddRequestHeaders("Content-Type: application/x-www-form-urlencoded");m_pFile->AddRequestHeaders("Accept-Encoding: gzip, deflate");if(m_pFile->SendRequest(NULL, 0, (LPVOID)(LPCTSTR)strPostData, strPostData == NULL ? 0 : _tcslen(strPostData))) {//get response status if success, return 200if (dwServiceType != AFX_INET_SERVICE_HTTP){m_pFile->QueryInfo(HTTP_QUERY_FLAG_NUMBER | HTTP_QUERY_STATUS_CODE,&dwStatus, &dwStatusLen, 0);}// while(m_pFile->ReadString(strLine)) // {// //m_strHtml += Convert(strLine, CP_ACP);// m_strHtml += strLine + char(13) + char(10);// }char szChars[BUFFER_SIZE + 1] = {0};string strRawResponse = "";UINT nReaded = 0;while ((nReaded = m_pFile->Read((void*)szChars, BUFFER_SIZE)) > 0){szChars[nReaded] = '\0';strRawResponse += szChars;memset(szChars, 0, BUFFER_SIZE + 1);}int unicodeLen = MultiByteToWideChar(CP_UTF8, 0, strRawResponse.c_str(), -1, NULL, 0);WCHAR *pUnicode = new WCHAR[unicodeLen + 1];memset(pUnicode,0,(unicodeLen+1)*sizeof(wchar_t));MultiByteToWideChar(CP_UTF8,0,strRawResponse.c_str(),-1, pUnicode,unicodeLen);DWORD dwNum = WideCharToMultiByte(CP_OEMCP,NULL,pUnicode,-1,NULL,0,NULL,FALSE);// WideCharToMultiByte的运用char *psText; // psText为char*的临时数组，作为赋值给std::string的中间变量psText = new char[dwNum];WideCharToMultiByte (CP_OEMCP,NULL,pUnicode,-1,psText,dwNum,NULL,FALSE);// WideCharToMultiByte的再次运用string szDst = psText;// std::string赋值delete []psText;// psText的清除strResponse = szDst;// char *ansi_str = UnicodeToUTF8(pUnicode);// // string str = ansi_str;// free(ansi_str);// // CString cs(str.c_str());delete []pUnicode; pUnicode = NULL;// strResponse = cs;Clear();} else {return FAILURE;}} else {return FAILURE;}} catch (CInternetException* e){Clear();DWORD dwErrorCode = e->m_dwError;e->Delete();DWORD dwError = GetLastError();// PRINT_LOG("dwError = %d", dwError, 0);if (ERROR_INTERNET_TIMEOUT == dwErrorCode){return OUTTIME;}else{return FAILURE;}}return SUCCESS;}int CHttpClient::HttpGet(LPCTSTR strUrl, LPCTSTR strPostData, string &strResponse){return ExecuteRequest("GET", strUrl, strPostData, strResponse);}int CHttpClient::HttpPost(LPCTSTR strUrl, LPCTSTR strPostData, string &strResponse){return ExecuteRequest("POST", strUrl, strPostData, strResponse);}wchar_t* CHttpClient::ANSIToUnicode(const char* str){int textlen;wchar_t * result;textlen = MultiByteToWideChar(CP_ACP, 0, str, -1, NULL, 0);result = (wchar_t *)malloc((textlen + 1) * sizeof(wchar_t));memset(result, 0, (textlen + 1) * sizeof(wchar_t));MultiByteToWideChar(CP_ACP, 0, str, -1, (LPWSTR)result, textlen);return result;}char* CHttpClient::UnicodeToUTF8(const wchar_t* str){char* result;int textlen;textlen = WideCharToMultiByte(CP_UTF8, 0, str, -1, NULL, 0, NULL, NULL);result = (char *)malloc((textlen + 1) * sizeof(char));memset(result, 0, sizeof(char) * (textlen + 1));WideCharToMultiByte(CP_UTF8, 0, str, -1, result, textlen, NULL, NULL);return result;}char* CHttpClient::UnicodeToANSI(const wchar_t* str){char* result;int textlen;textlen = WideCharToMultiByte(CP_ACP, 0, str, -1, NULL, 0, NULL, NULL);result = (char *)malloc((textlen + 1) * sizeof(char));memset(result, 0, sizeof(char) * (textlen + 1));WideCharToMultiByte(CP_ACP, 0, str, -1, result, textlen, NULL, NULL);return result;}
仔细观察上面所说函数，就可以看到在ExecuteRequest函数中处理了多字节转为utf8格式，后面单独写了几种其他转码方式，这几种方式在转码时总觉得有问题，详细介绍大家参考以上内容。
后面说下json数据，这里我们的http使用的是get请求方式，贴一份我查询会议的代码，内容相对全些，后面再介绍。
int CDatabaseManage::QueryMRInBooked( CString roomId,CString data ,HWND hwnd){TMRBookedInfo tmrBookedInfo;TMRBookedInfoArray tmrBookedInfoArray;tmrBookedInfoArray.clear();UINT uiRet = -1;if (m_httpCtrl == NULL){m_httpCtrl = new CHttpClient();}CString strUrl,strPostData ;strUrl.Format(_T("http://此处是ip地址:端口号/QueryConferenceRecord?content={\"Conference_Index\":\"%s\",\"RecordTime\":\"%s\"}"),roomId,data);string strResponse="";uiRet = m_httpCtrl->HttpGet(strUrl,strPostData,strResponse);if ((uiRet == SUCCESS) &&(!strResponse.empty())){Json::Value root;Json::Reader reader;if (reader.parse(strResponse,root,false)){if (root.isMember("content")){Json::Value jsResult=root["content"];if (jsResult.size()==0){return 0;}uiRet = jsResult.size();for(int i=0;i<jsResult.size();i++){if (jsResult[i].isMember("Index")){tmrBookedInfo.uiIdx = jsResult[i]["Index"].asInt();}if (jsResult[i].isMember("Subject")){tmrBookedInfo.strObj = jsResult[i]["Subject"].asCString();}if (jsResult[i].isMember("BeginTime")){tmrBookedInfo.uiBeginTime = jsResult[i]["BeginTime"].asCString();}if (jsResult[i].isMember("EndTime")){tmrBookedInfo.uiEndTime = jsResult[i]["EndTime"].asCString();}if (jsResult[i].isMember("UserName")){tmrBookedInfo.uiUserName =jsResult[i]["UserName"].asCString();}tmrBookedInfoArray.push_back(tmrBookedInfo);}::SendMessage(hwnd,CM_SHOWRECORD,(WPARAM)&tmrBookedInfoArray,0);}}}return uiRet;}
在strUrl中包含了我需要发送到服务端得ip、端口号，以及打包的json数据，后面使用HttpGet请求，此时就可以获取到服务端响应的json数据，保存在了strResponse中，这些都是在HttpClient.cpp中实现的，后面就是进行解析了，因为每个人写法习惯不一样，这里我只说下其中的conten是key值，后面的是value，至于定义key的内容，需要你们自己商量，或者你在了解下json格式，然后将你解析后数据再发送给所需要的部分就完成了json的解析发送。至此完成所有过程。
以下链接是对上一篇以及这一篇代码的总体实现，因为自身使用Unicode编码转换的，其中有我详细使用的http以及json数据的解析，创作不易，有兴趣可以看下。
链接：/download/hfuu1504011020/11057233
