一个C++ Log日志类

// Log.h  
#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(); //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  
  
#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()  
{  
    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_" + sDateStr + ".log");  
}  
  
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;  
}  
  
//本Log类,用于一般简单的Log文本文件输出.  
  
//test: main.cpp  
#include "Log.h"  
  
int main()  
{  
    Log mainLog;  
    mainLog.CommonLogInit();  
  
    mainLog << mainLog.GetTimeStr() << "测试Log类." << endl;  
}