C++使用Poco库封装一个FTP客户端类

0x00 Poco库中 Poco::Net::FTPClientSession

Poco库中FTP客户端类是 Poco::Net::FTPClientSession , 该类的接口比较简单。

上传文件接口： beginUpload() , endUpload()
下载文件接口： beginDownload() , endDownload()

0x01 FTPCli类说明

FTPCli类实现了连接FTP服务器，断开连接，上传文件和下载文件。
下载文件有两个接口，第一个接口从FTP服务器下载文件使用FTP服务器中的文件名，第二个接口是一个重载函数，可以将需要下载文件重新命名。

0x02 FTPCli类代码

#ifndef FTPCLI_H
#define FTPCLI_H#include <Poco/Poco.h>
#include <Poco/Exception.h>
#include <Poco/Net/FTPClientSession.h>
#include <string>class FTPCli
{
public:FTPCli(const std::string &host, const unsigned short port, const std::string &user, const std::string &passwd);~FTPCli();bool Connect(int retryCount = 3);void DisConnect();bool UploadFile(const std::string &localFilePath, const std::string &remoteFilePath);bool DownloadFile(const std::string &remoteFile);bool DownloadFile(const std::string &remoteFile, const std::string &localFile);private:Poco::Net::FTPClientSession m_ftpSession;std::string m_host;unsigned short m_port;std::string m_user;std::string m_passwd;
};#endif // FTPCLI_H

#include "ftpcli.h"
#include <iostream>
#include <fstream>
#include <iomanip>
#include <Poco/Path.h>FTPCli::FTPCli(const std::string &host, const unsigned short port, const std::string &user, const std::string &passwd): m_host(host), m_port(port), m_user(user), m_passwd(passwd)
{char ftpUrl[128];sprintf(ftpUrl, "ftp://%s:%s@%s:%d/", m_user.c_str(), m_passwd.c_str(),m_host.c_str(), m_port);printf("[%s:%d] %s\n", __FILE__, __LINE__, ftpUrl);
}FTPCli::~FTPCli()
{DisConnect();
}bool FTPCli::Connect(int retryCount)
{while (retryCount > 0){try{if (!m_ftpSession.isOpen()){m_ftpSession.open(m_host, m_port);}if (!m_ftpSession.isLoggedIn()){m_ftpSession.login(m_user, m_passwd);}printf("WorkingDirectory: %s\n", m_ftpSession.getWorkingDirectory().c_str());printf("%s\n", m_ftpSession.welcomeMessage().c_str());return true;}catch (Poco::Exception &ex){printf("Error connecting to FTP server: %s\n", ex.what());--retryCount;if (retryCount > 0){char errlog[128];sprintf(errlog, "ftp://%s:%s@%s:%d/", m_user.c_str(), m_passwd.c_str(),m_host.c_str(), m_port);printf("Retrying connect %s...\n", errlog);}}}// throw std::runtime_error("Failed to connect to FTP server after multiple attempts.");return false;
}void FTPCli::DisConnect()
{try{if (m_ftpSession.isOpen()){m_ftpSession.close();}}catch (Poco::Exception &ex){printf("Error: %s\n", ex.what());}
}bool FTPCli::UploadFile(const std::string &localFilePath, const std::string &remoteFilePath)
{try{// 设置FTP服务器的工作目录m_ftpSession.setWorkingDirectory(remoteFilePath);std::ifstream inFile(localFilePath, std::ios::in);if (!inFile.is_open()){printf("Failed to open file: %s\n", localFilePath.c_str());return false;}Poco::Path tmpPath(localFilePath);std::string tmpFileName = tmpPath.getBaseName();printf("[%s:%d] FileBaseName: %s\n", __FILE__, __LINE__, tmpFileName.c_str());auto &res = m_ftpSession.beginUpload(tmpFileName);std::string line;while (std::getline(inFile, line)){res << line;}inFile.close();m_ftpSession.endUpload();}catch (const Poco::Exception &ex){printf("Error connecting to FTP server: %s\n", ex.displayText().c_str());m_ftpSession.endUpload();return false;}return true;
}bool FTPCli::DownloadFile(const std::string &remoteFile)
{try{std::ofstream outFile(remoteFile, std::ios::out | std::ios::app);if (!outFile.is_open()){printf("Failed to open file: %s\n", remoteFile.c_str());return false;}auto &res = m_ftpSession.beginDownload(remoteFile);std::string line;while (std::getline(res, line)){outFile << line;}outFile.close();m_ftpSession.endDownload();}catch (const Poco::Exception &ex){printf("Error: %s\n", ex.displayText().c_str());m_ftpSession.endDownload();return false;}return true;
}bool FTPCli::DownloadFile(const std::string &remoteFile, const std::string &localFile)
{try{std::ofstream outFile(localFile, std::ios::out | std::ios::app);if (!outFile.is_open()){printf("Failed to open file: %s\n", localFile.c_str());return false;}auto &res = m_ftpSession.beginDownload(remoteFile);std::string line;while (std::getline(res, line)){outFile << line;}outFile.close();m_ftpSession.endDownload();}catch (const Poco::Exception &ex){printf("Error: %s\n", ex.displayText().c_str());m_ftpSession.endDownload();return false;}return true;
}