libcurl的主页:
http://curl.haxx.se/
头文件:
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/**//**********************************************************************
* Copyright (C) 2014 - - All Rights Reserved
*
* 文件名称: Downloader_LibCurl.h
* 摘 要: 下载器 - LibCurl实现
*
* 作 者: yanglinbo,
* 修 改: 查看文件最下方.
*
***********************************************************************/
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#ifndef __Downloader_LibCurl_H__
#define __Downloader_LibCurl_H__
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#include <curl/curl.h>
#include <fstream>
#include <string>
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class CDownloader
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{
public:
CDownloader(void);
virtual ~CDownloader(void);
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public:
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/**//// 线程入口函数
virtual bool run();
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/**//// 启动下载
virtual bool start(const std::string& strUrl, const std::string& strLocalFile);
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/**//// 停止下载
virtual bool stop();
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/**//// 是否运行状态
bool isRunning() const;
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protected:
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/**//// 写入回调
static size_t handleWrite(void *buffer, size_t size, size_t nmemb, void *userp);
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/**//// 进度回调
static size_t handleProgress(void *buffer, double dltotal, double dlnow, double ultotal, double ulnow);
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protected:
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/**//// 写入回调
size_t onWrite(void *buffer, size_t size, size_t nmemb);
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/**//// 进度回调
size_t onProgress(const double& dltotal, const double& dlnow);
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/**//// 下载回调
void onDownload();
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protected:
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/**//// 设置libcurl选项
void setOption();
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/**//// 清除数据
void clear();
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protected:
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CURL* m_pCurl; /**////< libcurl句柄
FILE* m_pFile; ///< 文件指针
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bool m_bRunning; /**////< 运行标志
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std::string m_strDownloadUrl; /**////< 下载链接
std::string m_strLocalFilePath; ///< 本地文件路径
};
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#endif
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实现文件:
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/**//**********************************************************************
* Copyright (C) 2014 - - All Rights Reserved
*
* 文件名称: Downloader_LibCurl.cpp
* 摘 要: 下载器 - LibCurl实现
*
* 作 者: yanglinbo,
* 修 改: 查看文件最下方.
*
***********************************************************************/
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#include "StdAfx.h"
#include "Downloader.h"
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CDownloader::CDownloader(void)
: m_pCurl(NULL)
, m_pFile(NULL)
, m_bRunning(false)
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{
}
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CDownloader::~CDownloader(void)
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{
stop();
}
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bool CDownloader::run()
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{
onDownload();
return true;
}
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bool CDownloader::isRunning() const
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{
return m_bRunning;
}
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void CDownloader::clear()
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{
if (m_pFile)
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{
fclose(m_pFile);
m_pFile = NULL;
}
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if (m_pCurl)
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{
curl_easy_cleanup(m_pCurl);
m_pCurl = NULL;
curl_global_cleanup();
}
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m_strDownloadUrl.clear();
m_strLocalFilePath.clear();
}
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void CDownloader::setOption()
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{
// 远程URL,支持 http, https, ftp
curl_easy_setopt(m_pCurl, CURLOPT_URL, m_strDownloadUrl.c_str());
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// 设置User-Agent
std::string useragent = _T("Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20100101 Firefox/13.0.1");
curl_easy_setopt(m_pCurl, CURLOPT_USERAGENT, useragent.c_str());
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// 设置重定向的最大次数
curl_easy_setopt(m_pCurl, CURLOPT_MAXREDIRS, 5);
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// 设置301、302跳转跟随location
curl_easy_setopt(m_pCurl, CURLOPT_FOLLOWLOCATION, 1);
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curl_easy_setopt(m_pCurl, CURLOPT_NOSIGNAL, 1L);
curl_easy_setopt(m_pCurl, CURLOPT_POST, false);
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// 下载内容回调函数
curl_easy_setopt(m_pCurl, CURLOPT_WRITEFUNCTION, handleWrite);
curl_easy_setopt(m_pCurl, CURLOPT_WRITEDATA, this);
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// 进度回调函数
curl_easy_setopt(m_pCurl, CURLOPT_NOPROGRESS, 0);
curl_easy_setopt(m_pCurl, CURLOPT_PROGRESSDATA, this);
curl_easy_setopt(m_pCurl, CURLOPT_PROGRESSFUNCTION, handleProgress);
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// 跳过服务器SSL验证,不使用CA证书
curl_easy_setopt(m_pCurl, CURLOPT_SSL_VERIFYPEER, 0L);
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// 验证服务器端发送的证书,默认是 2(高),1(中),0(禁用)
curl_easy_setopt(m_pCurl, CURLOPT_SSL_VERIFYHOST, 0L);
}
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bool CDownloader::start(const std::string& strUrl, const std::string& strLocalFile)
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{
if (strUrl.empty()) return false;
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if (m_bRunning == true) return true;
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clear();
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m_strDownloadUrl = strUrl;
m_strLocalFilePath = strLocalFile;
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// 初始化libcurl
m_pCurl = curl_easy_init();
if (m_pCurl == NULL)
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{
return false;
}
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// 设置libcurl的选项
setOption();
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// 创建文件
m_pFile = fopen(m_strLocalFilePath.c_str(), "wb");
if (m_pFile == NULL)
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{
return false;
}
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m_bRunning = true;
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return true;
}
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bool CDownloader::stop()
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{
clear();
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m_bRunning = false;
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return true;
}
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size_t CDownloader::handleWrite( void *buffer, size_t size, size_t nmemb, void *userp )
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{
CDownloader* pDownloader = (CDownloader*) userp;
if (pDownloader)
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{
return pDownloader->onWrite(buffer, size, nmemb);
}
return 0;
}
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size_t CDownloader::handleProgress( void *buffer, double dltotal, double dlnow, double ultotal, double ulnow )
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{
CDownloader* pDownloader = (CDownloader*) buffer;
if (pDownloader)
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{
pDownloader->onProgress(dltotal, dlnow);
}
return 0;
}
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size_t CDownloader::onProgress( const double& dltotal, const double& dlnow )
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{
TRACE("%.2f / %.2f (%.2g %%)\n", dlnow, dltotal, dlnow*100.0/dltotal);
return 0;
}
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size_t CDownloader::onWrite( void *buffer, size_t size, size_t nmemb )
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{
size_t return_size = fwrite(buffer, size, nmemb, m_pFile);
//std::cout << (char*) buffer << std::endl;
return return_size;
}
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void CDownloader::onDownload()
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{
// 执行下载
CURLcode return_code = CURLE_OK;
return_code = curl_easy_perform(m_pCurl);
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// 关闭文件
if (m_pFile)
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{
fclose(m_pFile);
m_pFile = NULL;
}
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// 下载失败
if (return_code != CURLE_OK)
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{
return;
}
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// 获取状态码
int response_code = 0;
curl_easy_getinfo(m_pCurl, CURLINFO_RESPONSE_CODE, &response_code);
if (response_code != 200)
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{
return;
}
}
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使用示例:
CDownloader downloader;
downloader.start("http://xingke.onlinedown.net:82/down/QQ2013SP6.zip", "QQ2013SP6.zip");
downloader.run();
需要说明的是,这个类本身其实是运行于线程环境下的,因此,加入到多线程环境下,并非难事。扩展或者修改也并不是难得事情,比之WinInet的实现来说,libcurl的实现实在是简单得无话可说。