C++ 读写csv文件

1.需求

数据库表数据->本地csv文件->数据库表数据,需要对csv文件进行读写操作,支持中文路径

2.接口用例

• UniTest.cpp

#include <iostream>
#include "CSVFile.h"

using namespace std;
int main()
{
    CSVFile dataFile("data.csv",",");

    //Cells生成Line
    vector<string> vecCells = {"1","2","3","4","5"};
    std::string strLine;
    dataFile.MakeLine(vecCells, strLine);
    cout << "生成的csv行数据 :" << strLine << endl;

    //Line解析成Cells
    vector<string> vecNewCells;
    dataFile.ParseLine(strLine, vecNewCells);


    //向文件写入Line
    dataFile.AppendLine(strLine);
    dataFile.AppendLine(strLine);

    //从文件读取所有Line
    vector<string> vecLines;
    dataFile.ReadLines(vecLines);
    cout << "读取多行数据内容 :" << endl;
    for (vector<string>::const_iterator iter = vecLines.begin();iter != vecLines.end();++iter)
    {
        cout << *iter << endl;
    }

    //向文件追加多个Line
    dataFile.AppendLines(vecLines);

    //清除文件内容,再写入多个Line
    dataFile.WriteLines(vecLines);


    std::string strPause;
    cin >> strPause;
    return 0;
}

3.接口及实现

• CSVFile.h

#pragma once

#include <vector>
#include <string>

using std::vector;
using std::string;

class CSVFile 
{
public:
    CSVFile(std::string strFileName, std::string strDelimeter);
    ~CSVFile();

    //解析csv行到cells
    void ParseLine(const std::string &strLine, std::vector<std::string> vecCells);
    //从cells生成csv行
    void MakeLine(const std::vector<std::string> &vecCells, std::string &strLine);
    //追加一行数据
    void AppendLine(std::string strLine);
    //清空后写多行数据
    void WriteLines(const std::vector<std::string> &vecLines);
    //追加多行数据
    void AppendLines(const std::vector<std::string> &vecLines);
    //读取文件数据
    void ReadLines(std::vector<std::string> &vecLines);
private:
    //文件名
    std::string m_strFileName;
    //分隔符
    std::string m_strDelimeter;
};

• CSVFile.cpp

#include <fstream>
#include "CSVFile.h"

using namespace std;

CSVFile::CSVFile(std::string strFileName, std::string strDelimeter)
{
    m_strFileName = strFileName;
    m_strDelimeter = m_strDelimeter;
}

CSVFile::~CSVFile()
{

}

void CSVFile::ParseLine(const std::string &strLine, std::vector<std::string> vecCells)
{
    std::string str = strLine;
    while (str.find(m_strDelimeter.c_str()) != std::string::npos)
    {
        unsigned int nPos = str.find(m_strDelimeter.c_str());
        std::string strCell = str.substr(0, nPos);
        str = str.substr(nPos + 1, str.size());
        vecCells.push_back(strCell);
    }
    vecCells.push_back(str);
}

void CSVFile::MakeLine(const std::vector<std::string> &vecCells, std::string &strLine)
{
    for (vector<string>::const_iterator iter = vecCells.begin(); iter != vecCells.end(); ++iter)
    {
        std::string strCell = *iter;
        strLine += strCell;
        //最后一个不带,
        if ((iter + 1) != vecCells.end())
        {
            strLine += m_strDelimeter;
        }
    }
}

void CSVFile::AppendLine(std::string strLine)
{
    ofstream ofs;
    std::locale loc = std::locale::global(std::locale(""));
    ofs.open(m_strFileName.c_str(), ios::out | ios::app);
    std::locale::global(loc);
    ofs << strLine << endl;
    ofs.close();
}

void CSVFile::AppendLines(const std::vector<std::string> &vecLines)
{
    ofstream ofs;
    std::locale loc = std::locale::global(std::locale(""));
    ofs.open(m_strFileName.c_str(), ios::out | ios::app);
    std::locale::global(loc);
    for (std::vector<std::string>::const_iterator iter = vecLines.begin(); iter != vecLines.end(); ++iter)
    {
        ofs << *iter << endl;
    }
    ofs.close();
}

void CSVFile::WriteLines(const std::vector<std::string> &vecLines)
{
    ofstream ofs;
    std::locale loc = std::locale::global(std::locale(""));
    ofs.open(m_strFileName.c_str(), ios::out | ios::trunc);
    std::locale::global(loc);
    for (std::vector<std::string>::const_iterator iter = vecLines.begin(); iter != vecLines.end(); ++iter)
    {
        ofs << *iter << endl;
    }
    ofs.close();
}

void CSVFile::ReadLines(std::vector<std::string> &vecLines)
{
    ifstream ifs;
    std::locale loc = std::locale::global(std::locale(""));
    ifs.open(m_strFileName.c_str(), ios::in);
    std::locale::global(loc);

    std::string strLine;
    while (getline(ifs, strLine))
    {
        vecLines.push_back(strLine);
    }
}