Question

我想在我的代码中记录不同的文件。

我如何使用xml配置在Log4cxx中执行此操作，或者在代码中以编程方式执行此操作...

假设我有1.k，k + 1，.. n个组件。
他们在同一个应用程序中运行
我希望组件k记录到Logger-k，k + 1组件记录到Logger-k + 1 同时

更新

Logger.addAppender（）方法：

log4cxx::helpers::Pool p; 

std::string paramAppender = "appxNormalAppender";
std::string paramFileName = "\\Logs\\MyLog.txt";

LOG4CXX_DECODE_CHAR(logAppender, paramAppender );
LOG4CXX_DECODE_CHAR(logFileName, paramFileName );


FileAppenderPtr fileAppender = 
logger->getLoggerRepository()->getRootLogger()->getAppender(logAppender);

if(fileAppender!= NULL)
{


    fileAppender->setFile(logFileName);

    fileAppender->activateOptions(p);

}

这不起作用，因为

假设我将FileName设置为Logger-k for k component，它会记录到记录器-k，然后我将文件名设置为Logger-k + 1为compoent k + 1，然后是组件k，和k + 1记录相同的loggerk + 1文件。似乎最后一个文件名覆盖或影响所有其他文件......

并且

所有组成部分1，... compoeent k，componentk + 1，.... 组件n在同一个应用程序中......

Answer 1

正常创建每个记录器，然后为每个记录器通过Logger.addAppender（）方法将FileAppender设置为所需的文件。

Answer 2

您需要为记录器创建单独的appender。在我的示例中，我创建了 afile1 和 afile2 appenders。我还创建了两个记录器： my.logger1 和 my.logger2 。当您使用 my.logger1 时，它会记录到 mylog1 文件，当您使用 my.logger2 时，它会记录到 mylog2 文件。

这是我的 log.properties 文件：

log4cplus.appender.afile1.layout=log4cplus::PatternLayout
log4cplus.appender.afile1.layout.ConversionPattern=%d [ %c{1} ] [ %-5p ] %m%n
log4cplus.appender.afile1=log4cplus::RollingFileAppender
log4cplus.appender.afile1.File=mylog1.log
log4cplus.appender.afile1.MaxFileSize=5MB
log4cplus.appender.afile1.MaxBackupIndex=2

log4cplus.appender.afile2.layout=log4cplus::PatternLayout
log4cplus.appender.afile2.layout.ConversionPattern=%d [ %c{1} ] [ %-5p ] %m%n
log4cplus.appender.afile2=log4cplus::RollingFileAppender
log4cplus.appender.afile2.File=mylog2.log
log4cplus.appender.afile2.MaxFileSize=5MB
log4cplus.appender.afile2.MaxBackupIndex=2

log4cplus.logger.my.logger1=INHERIT, afile1
log4cplus.additivity.my.logger1=false
log4cplus.logger.my.logger2=INHERIT, afile2
log4cplus.additivity.my.logger2=false

这是一个示例程序：
example.cpp：

#include <iostream>
#include <log4cplus/logger.h>
#include <log4cplus/loglevel.h>
#include <log4cplus/configurator.h>
#include <log4cplus/fileappender.h>

#define MYLOG1_INFO(logEvent) LOG4CPLUS_INFO (log4cplus::Logger::getInstance("my.logger1"), logEvent)
#define MYLOG2_INFO(logEvent) LOG4CPLUS_INFO (log4cplus::Logger::getInstance("my.logger2"), logEvent)

int main(int argc, char**argv)
{
    try
    {
        log4cplus::PropertyConfigurator::doConfigure("log.properties");
    }
    catch( ... )
    {
    std::cerr<<"Exception occured while opening log.properties\n";
    return -1;
    }
    MYLOG1_INFO("hello world!");
    MYLOG2_INFO("hello world!");
    return 0;
}

这是Makefile（我想我的log4cplus是在父目录中构建的）：

CXXFLAGS+=-I$(abspath ../log4cplus-1.0.4/include)
all: example.o
    $(CXX) $^ $(abspath ../log4cplus-1.0.4/src/.libs/liblog4cplus.a) -lpthread -o test

试试这个例子，您应该了解appender如何工作

Log4cplus主要类似于log4j。所以你可以阅读log4j的基本原理。要获得课程名称，您必须访问log4cplus.sourceforge.net

关于日志格式。 log4cplus的文档仅在doxygen中可用。所以在这里你可以阅读formating in pattern layout 如果你想记录进程ID，那么你应该在你的布局转换模式中使用％i 例如：

...
log4cplus.appender.afile2.layout.ConversionPattern=[%i] %m%n
...

它将记录进程ID和消息

Answer 3

对于动态组件，请尝试：

#include <boost/foreach.hpp>
#include <boost/thread.hpp>
#include <boost/bind.hpp>
#include <boost/lexical_cast.hpp>

#include <log4cxx/Logger.h>
#include <log4cxx/LogManager.h>
#include <log4cxx/xml/domconfigurator.h>
#include <log4cxx/FileAppender.h>
#include <log4cxx/SimpleLayout.h>
#include <log4cxx/helpers/transcoder.h>


void func(int k) {
    std::string strName = "Log." + boost::lexical_cast<std::string>(k);
    log4cxx::LoggerPtr log = log4cxx::Logger::getLogger(strName);
    LOG4CXX_DECODE_CHAR(fileName, strName + ".log");
    log4cxx::FileAppenderPtr appender(new log4cxx::FileAppender(new log4cxx::SimpleLayout, fileName, false));
    log->addAppender(appender);

    LOG4CXX_INFO(log, strName);

    log->removeAppender(appender);
}

int main(int argc, char * argv[]) {
    log4cxx::xml::DOMConfigurator::configure("trace.xml");
    if(log4cxx::Logger::getLogger("Log")->getAllAppenders().empty()) {
        std::cout << "failed to config log4cxx" << std::endl;
        return 1;
    }
    log4cxx::LoggerPtr log = log4cxx::Logger::getLogger("Log");

    boost::thread_group threadGroup;
    for(int k = 0; k != 3; ++k) {
        threadGroup.create_thread(boost::bind(func, k));
    }
    threadGroup.join_all();
    return 0;
}

使用简单的trace.xml

<?xml version="1.0" encoding="UTF-8" ?>
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
    <appender name="ConsoleAppender" class="org.apache.log4j.ConsoleAppender"> 
        <param name="Target" value="System.out"/> 
        <layout class="org.apache.log4j.SimpleLayout"/> 
    </appender>

    <root>
        <level value="all"/>
    </root> 

    <category name="Log">
        <level value="INFO"/>
        <appender-ref ref="ConsoleAppender"/>
    </category>
</log4j:configuration>

Answer 4

这是在对当前解决方案感到沮丧之后使用log4cxx中的类MDC在线程上下文中进行动态日志记录的另一种解决方案。它基本上允许将instanceid前缀添加到File的{{1}}属性中。它要求在加载配置文件之前正确编译和定义自定义FileAppender。与通常的旧log4cxx 0.10.0版本一起使用。可以与以下代码段一起使用：

FileAppender

可以与此属性配置文件一起使用：

#include <XFileAppender.h>

void PushInstance(const std::string &instanceid)
{
    MDC::put("__ITRInstanceId", value);
}

void PopInstance()
{
    MDC::remove("__ITRInstanceId");
}

int main()
{
    {
        auto logger = Logger::getLogger("Test1");
        PushInstance("user1");
        logger->log(log4cxx::Level::getInfo(), "Info");
        PopInstance();
    }

    {
        auto logger = Logger::getLogger("Test2");
        PushInstance("user1");
        logger->log(log4cxx::Level::getWarn(), "Warning");
        PopInstance();
    }

    // Imagine "Test1" and "Test2" used from different
    // threads acting as "user1"

    // Following line will ensure writers will be closed when "user1"
    // e.g. is logging out
    XFileAppender::CloseIstanceWriters("instance1");
    return 0;
}

XFileAppender标头：

# Default log filename. Can be overridden by system properties
LogFilename=File.log

# Appenders
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=[%d{dd/MM/yyyy HH:mm:ss}] %-6p: %m%n

log4j.appender.USER=org.apache.log4j.XFileAppender
log4j.appender.USER.File=${LogFilename}
log4j.appender.USER.layout=org.apache.log4j.PatternLayout
log4j.appender.USER.layout.ConversionPattern=[%d{dd/MM/yyyy HH:mm:ss}] %-6p: %m%n

# Root
log4j.rootLogger=WARN, stdout

# Classes
log4j.logger.Test1=INFO, USER
log4j.additivity.Test1 = false
log4j.logger.Test2=INFO, USER
log4j.additivity.Test2 = false

XFileAppender源：

// Copyright (c) 2019 Francesco Pretto
// This file is subject to the Apache License Version 2.0

#pragma once

#include "libdefs.h"
#include <memory>
#include <unordered_map>
#include <mutex>
#include <log4cxx/fileappender.h>

namespace log4cxx
{
    class ITR_LOGGING_SHARED_API XFileAppender : public FileAppender
    {
    private:
        struct InstanceWriter
        {
            typedef std::shared_ptr<InstanceWriter> Ptr;
            InstanceWriter(helpers::Pool& p);
            helpers::Mutex Mutex;
            helpers::WriterPtr Writer;
        };
        typedef std::unordered_map<LogString, XFileAppender *> AppenderIdentities;
    public:
        DECLARE_LOG4CXX_OBJECT(XFileAppender)
        BEGIN_LOG4CXX_CAST_MAP()
            LOG4CXX_CAST_ENTRY(XFileAppender)
            LOG4CXX_CAST_ENTRY_CHAIN(FileAppender)
        END_LOG4CXX_CAST_MAP()

        XFileAppender();

    public:
        void close() override;
        void append(const spi::LoggingEventPtr &event, helpers::Pool &p) override;
        void activateOptions(helpers::Pool &p) override;

    public:
        /**
        Clear all registered writers

        NOTE: It doesn't close them. This is useful example when reloading configuration
         */
        static void ClearWriters();

        /**
        Close all writers linked to instance
         */
        static void CloseIstanceWriters(const LogString &instanceid);

    private:
        InstanceWriter::Ptr getInstanceWriter(helpers::Pool &p);
        void CloseWriter(const LogString &istanceid);
        void closeWriter(InstanceWriter &writer);
        void closeWriter(helpers::Writer &writer);
        void closeWriters();
        helpers::WriterPtr createWriter(const LogString &instanceid, helpers::Pool& p);
        helpers::WriterPtr createWriter(const File &file, helpers::Pool& p);
        static void removeAppenderIstances(const LogString &appname, std::vector<LogString> &instanceIds);

    private:
        XFileAppender(const XFileAppender&);
        XFileAppender& operator=(const XFileAppender&);

    private:
        static helpers::Mutex s_mutex;
        static std::unordered_map<LogString, AppenderIdentities> s_appenderIdentities; // NOTE: Guarded by s_mutex
    private:
        bool m_failedWriter;                                                           // NOTE: Guarded by mutex
        helpers::WriterPtr m_writer;                                                   // NOTE: Guarded by mutex
        std::unordered_map<LogString, InstanceWriter::Ptr> m_instanceWriters;          // NOTE: Guarded by mutex

    }; // class XFileAppender
    LOG4CXX_PTR_DEF(XFileAppender);

}  // namespace log4cxx

使用log4cxx登录到不同的文件

4 个答案: