你的位置:首页 > ASP.net教程

[ASP.net教程]使用log4net将日志文件输出为csv格式

  我们在编写程序时,会在程序运行过程中记录一些日志。log4net作为一款经久耐用的日志组件,值得我们信赖。在中小型公司中,往往没有专业的日志服务器来处理应用程序产生的日志,而格式化不好的日志文件又为上线后日志的统计、分析、查找造成了困难。

  Excel作为一款常用的办公软件,用来处理一些中小数量级的数据还是游刃有余的。如果log4net输出的日志能够直接导入Excel,那么查询和分析起来岂不是要快很多?

  我们有很多方法可以实现这个功能,csv的优势是其文件格式比较简单,可以用任意的文本编辑器打开,而且解析起来比较方便。效果如下:

 

  新建控制台程序,引用log4net类库这些步骤不必说,直接进入正题,我们需要增加4个类文件 CsvTextWriter 、 NewFieldConverter 、 EndRowConverter 和 CsvPatternLayout。

CsvTextWriter.cs

 1 using System.IO; 2 using System.Text; 3  4 namespace CoderBusy.Log4Net.Layout 5 { 6   public class CsvTextWriter : TextWriter 7   { 8     private readonly TextWriter _textWriter; 9 10     public CsvTextWriter(TextWriter textWriter)11     {12       _textWriter = textWriter;13     }14 15     public override Encoding Encoding => _textWriter.Encoding;16 17     public override void Write(char value)18     {19       _textWriter.Write(value);20       if (value == '"')21         _textWriter.Write(value);22     }23 24     public void WriteQuote()25     {26       _textWriter.Write('"');27     }28   }29 }

NewFieldConverter.cs

 1 using System.IO; 2 using log4net.Util; 3  4 namespace CoderBusy.Log4Net.Layout 5 { 6   public class NewFieldConverter : PatternConverter 7   { 8     protected override void Convert(TextWriter writer, object state) 9     {10       var ctw = writer as CsvTextWriter;11       ctw?.WriteQuote();12 13       writer.Write(',');14 15       ctw?.WriteQuote();16     }17   }18 }

EndRowConverter.cs

 1 using System.IO; 2 using log4net.Util; 3  4 namespace CoderBusy.Log4Net.Layout 5 { 6   public class EndRowConverter : PatternConverter 7   { 8     protected override void Convert(TextWriter writer, object state) 9     {10       var ctw = writer as CsvTextWriter;11 12       ctw?.WriteQuote();13 14       writer.WriteLine();15     }16   }17 }

CsvPatternLayout.cs

 1 using System.IO; 2 using log4net.Core; 3 using log4net.Layout; 4  5 namespace CoderBusy.Log4Net.Layout 6 { 7   public class CsvPatternLayout : PatternLayout 8   { 9     public override void ActivateOptions()10     {11       AddConverter("newfield", typeof(NewFieldConverter));12       AddConverter("endrow", typeof(EndRowConverter));13       base.ActivateOptions();14     }15 16     public override void Format(TextWriter writer, LoggingEvent loggingEvent)17     {18       var ctw = new CsvTextWriter(writer);19       ctw.WriteQuote();20       base.Format(ctw, loggingEvent);21     }22   }23 }

  在书写 log4net 的配置文件时,只要将 appender 的 layout 设置为 CoderBusy.Log4Net.Layout.CsvPatternLayout ,且设置好日志头,日志格式即可。注意,header后需要编写换行字符,%newfield代表字段分隔符,%endrow代表一行结束。

   <layout type="CoderBusy.Log4Net.Layout.CsvPatternLayout,CoderBusy.Log4Net">    <header value="Time,Thread,Level,Logger,Message,Exception&#13;&#10;" />    <conversionPattern     value="%date{yyyy-MM-dd HH:mm:ss}%newfield%thread%newfield%level%newfield%logger%newfield%message%newfield%exception%endrow" />   </layout>

  我为初学者准备了一个log4net的配置文件。这个配置文件会将日志在控制台和csv文件中同时输出,每天一个CSV文件(本地时间),且控制台中,不同的日志级别会有不同的颜色。 

 1 <??> 2  3 <configuration> 4  <configSections> 5   <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" /> 6  </configSections> 7  <log4net ="http://www.w3.org/2001/> 8   <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender"> 9    <param name="File" value="Logs/" />10    <param name="AppendToFile" value="True" />11    <param name="MaxSizeRollBackups" value="10" />12    <param name="StaticLogFileName" value="false" />13    <param name="DatePattern" value="yyyy-MM-dd&quot;.csv&quot;" />14    <param name="RollingStyle" value="Date" />15    <layout type="CoderBusy.Log4Net.Layout.CsvPatternLayout,CoderBusy.Log4Net">16     <header value="Time,Thread,Level,Logger,Message,Exception&#13;&#10;" />17     <conversionPattern18      value="%date{yyyy-MM-dd HH:mm:ss}%newfield%thread%newfield%level%newfield%logger%newfield%message%newfield%exception%endrow" />19    </layout>20   </appender>21 22   <appender name="ColoredConsoleAppender" type="log4net.Appender.ColoredConsoleAppender">23    <mapping>24     <level value="ERROR" />25     <foreColor value="Red" />26    </mapping>27    <mapping>28     <level value="INFO" />29     <foreColor value="Green" />30    </mapping>31 32    <layout type="log4net.Layout.PatternLayout">33     <conversionPattern value="# %date{HH:mm:ss} [%thread] %-5level %logger #%newline%message%newline" />34    </layout>35    <filter type="log4net.Filter.LevelRangeFilter">36     <param name="LevelMin" value="DEBUG" />37     <param name="LevelMax" value="FATAL" />38    </filter>39   </appender>40 41   <root>42    <!-- OFF < FATAL < ERROR < WARN < INFO < DEBUG < ALL -->43    <level value="ALL" />44    <appender-ref ref="RollingLogFileAppender" />45    <appender-ref ref="ColoredConsoleAppender" />46   </root>47  </log4net>48 </configuration>

  配合以上配置,测试一下功能。

 1 using System; 2 using log4net; 3 using log4net.Config; 4  5 [assembly: "log4net.config")] 6  7 namespace CoderBusy.Log4Net.Tests 8 { 9   internal class Program10   {11     public static void Main(string[] args)12     {13       var log = LogManager.GetLogger("Default");14       log.Debug("Message", new Exception("Test Exception"));15       log.Info("Hello World.");16       log.WarnFormat("A={0} B={1}", "\"123123", Environment.NewLine);17       Console.ReadLine();18     }19   }20 }

Logs文件夹中,生成的csv文件内容如下:

Time,Thread,Level,Logger,Message,Exception
"2016-08-25 23:13:19","9","DEBUG","Default","Message","System.Exception: Test Exception
"
"2016-08-25 23:13:19","9","INFO","Default","Hello World.",""
"2016-08-25 23:13:19","9","WARN","Default","A=""123123 B=
",""

  输出字段被使用双引号包裹,且消息体中的双引号被重复输出。这样的结果表明我们的程序是正常的。本文的代码可以在 http://pan.baidu.com/s/1hr4EOPu 下载,谢谢阅读,并祝你成功。