C++ 一个简单的log类的实现

c++有好多日志类库，今天在网上学习了一个简单的日志类库的写法。

直接看代码 ：

Log.h文件：

#ifndef LOG_H
#define LOG_H

#include <fstream>
#include <string>
#include <sstream>
#include <ctime>

using namespace std;

/**
* 用于输出log文件的类.
*/
class Log
{
public:
Log();
~Log();

bool Open(string strFileName);
void Close();

bool CommonLogInit(string name); //打开默认的log 文件

void Enable();
void Disable();

string GetTimeStr();

template <typename T> void LogOut(const T& value)
{
if (m_bEnabled)
{
m_tOLogFile << value;
}
}

template <typename T> void LogOutLn(const T& value)
{
if (m_bEnabled)
{
m_tOLogFile << value << endl;
}
}

void LogOutLn()
{
if (m_bEnabled)
{
m_tOLogFile << endl;
}
}

template <typename T> Log& operator<<(const T& value)
{
if (m_bEnabled)
{
m_tOLogFile << value;
}
return (*this);
}

Log& operator<<(ostream& (*_Pfn)(ostream&))
{
if (m_bEnabled)
{
(*_Pfn)(m_tOLogFile);
}
return (*this);
}

private:
template<typename T> string ValueToStr(T value)
{
ostringstream ost;
ost << value;
return ost.str();
}
private:
ofstream m_tOLogFile;

bool m_bEnabled;
};

#endif

Log.cpp文件：

#include "Log.h"

Log::Log()
:m_bEnabled(true)
{
}

Log::~Log()
{
}

bool Log::Open(string sFileName)
{
m_tOLogFile.open(sFileName.c_str(), ios_base::out | ios_base::app);

if (!m_tOLogFile)
{
return false;
}

return true;
}

void Log::Close()
{
if (m_tOLogFile.is_open())
{
m_tOLogFile.close();
}
}

bool Log::CommonLogInit(string name)
{
time_t tNowTime;
time(&tNowTime);

tm* tLocalTime = localtime(&tNowTime);

//得到日期的字符串
string sDateStr = ValueToStr(tLocalTime->tm_year + 1900) + "-" +
ValueToStr(tLocalTime->tm_mon + 1) + "-" +
ValueToStr(tLocalTime->tm_mday);

return Open( "Log\\"+name + sDateStr + ".txt");
}

void Log::Enable()
{
m_bEnabled = true;
}

void Log::Disable()
{
m_bEnabled = false;
}

//得到当前时间的字符串
string Log::GetTimeStr()
{
time_t tNowTime;
time(&tNowTime);

tm* tLocalTime = localtime(&tNowTime);

//"2011-07-18 23:03:01 ";
string strFormat = "%Y-%m-%d %H:%M:%S ";

char strDateTime[30] = { '\0' };
strftime(strDateTime, 30, strFormat.c_str(), tLocalTime);

string strRes = strDateTime;

return strRes;
}
使用实例main.cpp
#include "Log.h"

int main()
{
Log mainLog;
string a = "log";
mainLog.CommonLogInit(a);

mainLog << mainLog.GetTimeStr() << "这里是需要自己输入的信息" << endl;
}