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

1 #pragma once
 2 
 3 #include <vector>
 4 #include <string>
 5 
 6 using std::vector;
 7 using std::string;
 8 
 9 class CSVFile 
10 {
11 public:
12     CSVFile(std::string strFileName, std::string strDelimeter);
13     ~CSVFile();
14 
15     //解析csv行到cells
16     void ParseLine(const std::string &strLine, std::vector<std::string> vecCells);
17     //从cells生成csv行
18     void MakeLine(const std::vector<std::string> &vecCells, std::string &strLine);
19     //追加一行数据
20     void AppendLine(std::string strLine);
21     //清空后写多行数据
22     void WriteLines(const std::vector<std::string> &vecLines);
23     //追加多行数据
24     void AppendLines(const std::vector<std::string> &vecLines);
25     //读取文件数据
26     void ReadLines(std::vector<std::string> &vecLines);
27 private:
28     //文件名
29     std::string m_strFileName;
30     //分隔符
31     std::string m_strDelimeter;
32 };

• CSVFile.cpp

1 #include <fstream>
 2 #include "CSVFile.h"
 3 
 4 using namespace std;
 5 
 6 CSVFile::CSVFile(std::string strFileName, std::string strDelimeter)
 7 {
 8     m_strFileName = strFileName;
 9     m_strDelimeter = m_strDelimeter;
10 }
11 
12 CSVFile::~CSVFile()
13 {
14 
15 }
16 
17 void CSVFile::ParseLine(const std::string &strLine, std::vector<std::string> vecCells)
18 {
19     std::string str = strLine;
20     while (str.find(m_strDelimeter.c_str()) != std::string::npos)
21     {
22         unsigned int nPos = str.find(m_strDelimeter.c_str());
23         std::string strCell = str.substr(0, nPos);
24         str = str.substr(nPos + 1, str.size());
25         vecCells.push_back(strCell);
26     }
27     vecCells.push_back(str);
28 }
29 
30 void CSVFile::MakeLine(const std::vector<std::string> &vecCells, std::string &strLine)
31 {
32     for (vector<string>::const_iterator iter = vecCells.begin(); iter != vecCells.end(); ++iter)
33     {
34         std::string strCell = *iter;
35         strLine += strCell;
36         //最后一个不带,
37         if ((iter + 1) != vecCells.end())
38         {
39             strLine += m_strDelimeter;
40         }
41     }
42 }
43 
44 void CSVFile::AppendLine(std::string strLine)
45 {
46     ofstream ofs;
47     std::locale loc = std::locale::global(std::locale(""));
48     ofs.open(m_strFileName.c_str(), ios::out | ios::app);
49     std::locale::global(loc);
50     ofs << strLine << endl;
51     ofs.close();
52 }
53 
54 void CSVFile::AppendLines(const std::vector<std::string> &vecLines)
55 {
56     ofstream ofs;
57     std::locale loc = std::locale::global(std::locale(""));
58     ofs.open(m_strFileName.c_str(), ios::out | ios::app);
59     std::locale::global(loc);
60     for (std::vector<std::string>::const_iterator iter = vecLines.begin(); iter != vecLines.end(); ++iter)
61     {
62         ofs << *iter << endl;
63     }
64     ofs.close();
65 }
66 
67 void CSVFile::WriteLines(const std::vector<std::string> &vecLines)
68 {
69     ofstream ofs;
70     std::locale loc = std::locale::global(std::locale(""));
71     ofs.open(m_strFileName.c_str(), ios::out | ios::trunc);
72     std::locale::global(loc);
73     for (std::vector<std::string>::const_iterator iter = vecLines.begin(); iter != vecLines.end(); ++iter)
74     {
75         ofs << *iter << endl;
76     }
77     ofs.close();
78 }
79 
80 void CSVFile::ReadLines(std::vector<std::string> &vecLines)
81 {
82     ifstream ifs;
83     std::locale loc = std::locale::global(std::locale(""));
84     ifs.open(m_strFileName.c_str(), ios::in);
85     std::locale::global(loc);
86 
87     std::string strLine;
88     while (getline(ifs, strLine))
89     {
90         vecLines.push_back(strLine);
91     }
92 }

原文链接: https://www.cnblogs.com/SwiftChocolate/p/13460009.html

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