CSv纯C++解析

ゝ一纸荒年。 2022-09-21 11:59 159阅读 0赞

#include <string>
    #include <vector>
    namespace MyCsvParser
    {
    	using namespace std;
    	class Row
    	{
    	public:
    		Row(){}
    		void push_back(const string&vale){ m_value.push_back(vale); }
    		void setHeader(const vector<string>*header){ m_head = header; }
    		int getSize(){ return m_value.size(); }
    		string &operator[](unsigned int key)
    		{
    			if (key < m_value.size())return m_value[key];
    			
    			throw "can't is return this m_value pos error";
    		}
    		string&operator[](const string&value)
    		{
    			int pos = 0;
    			vector<string>::const_iterator it;
    			for (it = m_head->begin(); it != m_head->end(); ++it)
    			{
    				if (*it == value)
    					return m_value[pos];
    				++pos;
    			}
    			throw "can't return this m_head is pos error";
    		}
    	private:
    		const vector<string>*m_head;
    		vector<string>m_value;
    	};
    
    	class NowCsvParser
    	{
    	public:
    		NowCsvParser();
    		NowCsvParser(const string&filename);
    		~NowCsvParser();
    		bool Parser(const string &filename);
    		int getRowCount(){ return m_rowCount.size(); }
    		int getColmunCount(){ return m_head.size(); }
    		Row &operator[](unsigned int key)
    		{
    			if (key < m_rowCount.size())return m_rowCount[key];
    			throw "can't is return this m_rowCount pos Erorr";
    		}
    	private:
    		bool Load(const string &filename,string &date);
    		void setHead();
    	private:
    		vector<Row>m_rowCount;
    		vector<string>m_head;
    		string error;
    	};
    
    }

#define _CRT_SECURE_NO_WARNINGS
    #include "NowCsvParser.h"
    
    namespace MyCsvParser{
    
    NowCsvParser::NowCsvParser()
    {
    }
    
    NowCsvParser::NowCsvParser(const string &fielname)
    {
    	if (!Parser(fielname))
    		throw "can't is this create parser error";
    }
    
    NowCsvParser::~NowCsvParser()
    {
    }
    
    bool NowCsvParser::Load(const string &filename,string &Data)
    {
    	FILE *pfile = fopen(filename.c_str(),"rb");
    	if (!pfile)
    		return false;
    
    	long len=0;
    	fseek(pfile, 0, SEEK_END);
    	len = ftell(pfile);
    	char *fileBuff = new char[len + 1];
    	fseek(pfile,0,0);
    	fread(fileBuff,1,len,pfile);
    	fclose(pfile);
    	fileBuff[len] = 0;
    	Data.assign(fileBuff, len);
    	delete[]fileBuff;
    	return true;
    }
    bool NowCsvParser::Parser(const string &filename)
    {
    	m_head.clear();
    	m_rowCount.clear();
    	string text;
    	if (!Load(filename, text) || text.size() == 0)
    		return false;
    
    
    	enum StateField
    	{
    		NewFiedlState,//开始新的字段
    		NonFieldState,//非引号字段
    		QuotesField,//引号字段
    		FieldSeparator,//字段分隔
    		QuoteInQuoteField,//引号中的引号字段
    		RowField,//分隔符/r
    		Error//语法错误
    	};
    
    	Row fields;
    	string strfield;
    	StateField State=NewFiedlState;
    	for (int i = 0, size = text.size(); i < size; i++)
    	{
    		char ch = text[i];
    		
    		switch (State)
    		{
    		case NewFiedlState:
    		{
    							  if (ch == ',')
    							  {
    								  fields.push_back("");
    								  strfield.clear();
    								  State = FieldSeparator;
    							  }
    							  else if (ch == '"')
    							  {
    								  State = QuotesField;
    							  }
    							  else if (ch == '\r'||ch=='\n')
    							  {
    								  this->error = "语法错误：开头表出现空格";
    								  State = Error;
    							  }
    							  else
    							  {
    								  strfield.push_back(ch);
    								  State = NonFieldState;
    							  }
    
    		}
    			break;
    		case NonFieldState:
    		{
    							  if (ch == ',')
    							  {
    								  fields.push_back(strfield);
    								  strfield.clear();
    								  State = FieldSeparator;
    							  }
    							  else if (ch == '\r')
    							  {
    								  fields.push_back(strfield);
    								  State = RowField;
    							  }
    							  else
    							  {
    								  strfield.push_back(ch);
    							  }
    		}
    			break;
    		case QuotesField:
    		{
    							if (ch == '"')
    								State = QuoteInQuoteField;
    							else
    							{
    								strfield.push_back(ch);
    							}
    		}
    			break;
    		case FieldSeparator:
    		{
    							   if (ch == ',')
    							   {
    								   fields.push_back("");
    							   }
    							   else if (ch == '"')
    								   State = QuotesField;
    							   else if (ch == '\r')
    							   {
    								   fields.push_back("");
    								   State = RowField;
    							   }
    							   else
    							   {
    								   strfield.push_back(ch);
    								   State = NonFieldState;
    							   }
    		}
    			break;
    		case QuoteInQuoteField:
    		{
    								  if (ch == '"')
    								  {
    									  strfield.push_back(ch);
    									  State = QuotesField;
    								  }
    								  else if (ch == '\r')
    								  {
    									  fields.push_back(strfield);
    									  State = RowField;
    								  }
    								  else if (ch == ',')
    								  {
    									  fields.push_back(strfield);
    									  strfield.clear();
    									  State = FieldSeparator;
    								  }
    								  else
    								  {
    									  this->error = "语法错误:转义字符错误 \ 不能完成转义";
    									  State = Error;
    								  }
    
    		}
    			break;
    		case RowField:
    		{
    						 if (ch == '\n')
    						 {
    							 m_rowCount.push_back(fields);
    							 fields = Row();
    							 strfield.clear();
    							 State = NewFiedlState;
    						 }
    						 else
    						 {
    							 this->error = "语法错误,没有紧跟 换行";
    							 State = Error;
    						 }
    		}
    			break;
    		case Error:
    		{
    					  return false;
    		}
    			break;
    		default:
    			break;
    		}
    
    	}
    	switch (State)
    	{
    	case NewFiedlState:
    		break;
    	case NonFieldState:
    		fields.push_back(strfield);
    		m_rowCount.push_back(fields);
    		break;
    	case QuotesField:
    		this->error = "语法错误 ,引用字段未闭合";
    		break;
    	case FieldSeparator:
    		fields.push_back(strfield);
    		m_rowCount.push_back(fields);
    		break;
    	case QuoteInQuoteField:
    		fields.push_back(strfield);
    		m_rowCount.push_back(fields);
    		break;
    	case RowField:
    
    		break;
    	case Error:
    
    		break;
    	}
    	if (!error.empty())
    	{
    		return false;
    	}
    	setHead();
    	return true;
    }
    
    void NowCsvParser::setHead()
    {
    	m_head.clear();
    	for (int i = 0; i < m_rowCount[0].getSize(); i++)
    	{
    		m_head.push_back(m_rowCount[0][i]);
    	}
    	for (int i = 0; i < m_rowCount.size(); i++)
    	{
    		m_rowCount[i].setHeader(&m_head);
    	}
    
    }
    
    
    
    }

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[Center]: /images/20220721/76bde40996f94769be04a6bfb0230d58.png