基于libcurl实现REST风格http/https的get和post

c/c++开发中经常要用到http/https协议，直接使用socket工作量很大，要是使用socket实现https，那更不可思议，开源的c/c++的http客户端框架，libcurl是首选，而且也相当成熟稳定，最近C++项目中用到https请求，就做下研究。

libcurl简介(来源官网)

libcurl是一个跨平台的网络协议库，支持http, https, ftp, gopher, telnet, dict, file, 和ldap 协议。libcurl同样支持HTTPS证书授权，HTTP POST, HTTP PUT, FTP 上传, HTTP基本表单上传，代理，cookies,和用户认证。官网地址：https://curl.haxx.se/libcurl/

实现HTTP/GET：

Get.cpp

 /********************************************************
 Copyright (C),  2016-2018,
 FileName:        Get
 Author:            woniu201
 Email:             wangpengfei.201@163.com
 Created:           2018/10/15
 Description:    实现HTTP/HTTPS GET请求
 ********************************************************/
 #include "main.h"

 size_t WriteGetResp(void *buffer, size_t size, size_t nmemb, void *userp)
 {
     ((string*)userp)->append((char*)buffer, , size*nmemb);
     return size*nmemb;
 }

 /************************************
 @ Brief:        GET请求
 @ Author:        woniu201
 @ Created:        2018/10/15
 @ Return:
 ************************************/
 int HttpGet(char* url)
 {
     string respData;
     CURL* curl;
     CURLcode res;

     curl = curl_easy_init();
     if (curl == NULL)
     {
         return ;
     }

     curl_easy_setopt(curl, CURLOPT_URL, url);
     curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteGetResp);
     curl_easy_setopt(curl, CURLOPT_WRITEDATA, &respData);

 //      curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS, 5000); //libcurl存在毫秒超时bug,如果设备小于1000ms立即返回失败
 //      curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS, 5000); //设置超时时间

     bool bCA = FALSE;
     if (!bCA)
     {
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, FALSE);//设定为不验证证书和HOST
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, FALSE);
     }
     else
     {
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, TRUE);
         curl_easy_setopt(curl, CURLOPT_CAINFO, "");
     }

     res = curl_easy_perform(curl);
     if (res != CURLE_OK)
     {
         cout << curl_easy_strerror(res) << endl;
     }

     curl_easy_cleanup(curl);

     cout << Utf8ToAscii(respData) << endl;
     return ;
 }

实现HTTP/POST：

Post.cpp

 /********************************************************
 Copyright (C),  2016-2018,
 FileName:        Post
 Author:            woniu201
 Email:             wangpengfei.201@163.com
 Created:           2018/10/15
 Description:    实现HTTP/HTTPS POST请求
 ********************************************************/
 #include "main.h"

 size_t WritePostBodyResp(void *buffer, size_t size, size_t nmemb, void *userp)
 {
     ((string*)userp)->append((char*)buffer, , size*nmemb);
     return size*nmemb;
 }

 size_t WritePostHeaderResp(void *buffer, size_t size, size_t nmemb, void *userp)
 {
     ((string*)userp)->append((char*)buffer, , size*nmemb);
     return size*nmemb;
 }

 /************************************
 @ Brief:        POST请求
 @ Author:        woniu201
 @ Created:        2018/10/15
 @ Return:
 ************************************/
 int HttpPost(char* url, char* body)
 {
     string respBodyData;
     string respHeadData;
     CURL* curl;
     CURLcode res;

     //设置头
     struct curl_slist *headers = NULL;
     headers = curl_slist_append(headers, "Content-Type:application/json;charset=UTF-8");

     curl = curl_easy_init();
     if (curl == NULL)
     {
         return ;
     }

     curl_easy_setopt(curl, CURLOPT_URL, url);
     curl_easy_setopt(curl, CURLOPT_POSTFIELDS, body);
     curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);

     curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, WritePostHeaderResp);
     curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WritePostBodyResp);
     curl_easy_setopt(curl, CURLOPT_WRITEHEADER, &respHeadData);
     curl_easy_setopt(curl, CURLOPT_WRITEDATA, &respBodyData);

     //      curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS, 5000); //libcurl存在毫秒超时bug,如果设备小于1000ms立即返回失败
     //      curl_easy_setopt(curl, CURLOPT_TIMEOUT_MS, 5000); //设置超时时间

     bool bCA = FALSE;
     if (!bCA)
     {
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, FALSE);//设定为不验证证书和HOST
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, FALSE);
     }
     else
     {
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, TRUE);
         curl_easy_setopt(curl, CURLOPT_CAINFO, "");
     }

     res = curl_easy_perform(curl);
     if (res != CURLE_OK)
     {
         cout << curl_easy_strerror(res) << endl;
     }
     curl_slist_free_all(headers);
     curl_easy_cleanup(curl);

     cout << Utf8ToAscii(respHeadData) << endl;
     cout << Utf8ToAscii(respBodyData) << endl;

     return ;
 }

其他代码：

utils.cpp

 /********************************************************
 Copyright (C),  2016-2018,
 FileName:        utils
 Author:            woniu201
 Email:             wangpengfei.201@163.com
 Created:           2018/10/15
 Description:    ASSIC--UTF8互转
 ********************************************************/
 #include "main.h"
 #include <string>
 #include <Windows.h>
 #include <wchar.h>
 using namespace std;

 wstring    AsciiToUnicode(const string& str) {
     // 预算-缓冲区中宽字节的长度
     int unicodeLen = MultiByteToWideChar(CP_ACP, , str.c_str(), -, nullptr, );
     // 给指向缓冲区的指针变量分配内存
     wchar_t *pUnicode = (wchar_t*)malloc(sizeof(wchar_t)*unicodeLen);
     // 开始向缓冲区转换字节
     MultiByteToWideChar(CP_ACP, , str.c_str(), -, pUnicode, unicodeLen);
     wstring ret_str = pUnicode;
     free(pUnicode);
     return ret_str;
 }
 string UnicodeToAscii(const wstring& wstr) {
     // 预算-缓冲区中多字节的长度
     int ansiiLen = WideCharToMultiByte(CP_ACP, , wstr.c_str(), -, nullptr, , nullptr, nullptr);
     // 给指向缓冲区的指针变量分配内存
     char *pAssii = (char*)malloc(sizeof(char)*ansiiLen);
     // 开始向缓冲区转换字节
     WideCharToMultiByte(CP_ACP, , wstr.c_str(), -, pAssii, ansiiLen, nullptr, nullptr);
     string ret_str = pAssii;
     free(pAssii);
     return ret_str;
 }

 wstring Utf8ToUnicode(const string& str) {
     // 预算-缓冲区中宽字节的长度
     int unicodeLen = MultiByteToWideChar(CP_UTF8, , str.c_str(), -, nullptr, );
     // 给指向缓冲区的指针变量分配内存
     wchar_t *pUnicode = (wchar_t*)malloc(sizeof(wchar_t)*unicodeLen);
     // 开始向缓冲区转换字节
     MultiByteToWideChar(CP_UTF8, , str.c_str(), -, pUnicode, unicodeLen);
     wstring ret_str = pUnicode;
     free(pUnicode);
     return ret_str;
 }
 string UnicodeToUtf8(const wstring& wstr) {
     // 预算-缓冲区中多字节的长度
     int ansiiLen = WideCharToMultiByte(CP_UTF8, , wstr.c_str(), -, nullptr, , nullptr, nullptr);
     // 给指向缓冲区的指针变量分配内存
     char *pAssii = (char*)malloc(sizeof(char)*ansiiLen);
     // 开始向缓冲区转换字节
     WideCharToMultiByte(CP_UTF8, , wstr.c_str(), -, pAssii, ansiiLen, nullptr, nullptr);
     string ret_str = pAssii;
     free(pAssii);
     return ret_str;
 }  

 /************************************
 @ Brief:        ASSIC转UTF8
 @ Author:        woniu201
 @ Created:        2018/10/16
 @ Return:
 ************************************/
 string AsciiToUtf8(const string& str) {
     return UnicodeToUtf8(AsciiToUnicode(str));
 }  

 /************************************
 @ Brief:        UTF8转ASSIC
 @ Author:        woniu201
 @ Created:        2018/10/16
 @ Return:
 ************************************/
 string Utf8ToAscii(const string& str) {
     return UnicodeToAscii(Utf8ToUnicode(str));
 }  

 #ifndef _MAIN_H
 #define _MAIN_H

 #include <iostream>
 #include <string>
 #include "include/curl.h"

 using namespace std;

 #pragma comment(lib, "ssleay32.lib")
 #pragma comment(lib, "libcurl.lib")

 string AsciiToUtf8(const string& str);
 string Utf8ToAscii(const string& str);

 int HttpGet(char* url);
 int HttpPost(char* url, char* body);
 int HttpDownload(char* url,  char* filePath);
 #endif

对应libcurl库和头文件下载地址(支持HTTPS)：点击下载

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