使用log4net将日志文件输出为csv格式
2021-02-17 13:17
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
" />
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 xml version="1.0" encoding="utf-8"?> 2 3 configuration> 4 configSections> 5 section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" /> 6 configSections> 7 log4net xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> 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".csv"" /> 14 param name="RollingStyle" value="Date" /> 15 layout type="CoderBusy.Log4Net.Layout.CsvPatternLayout,CoderBusy.Log4Net"> 16 header value="Time,Thread,Level,Logger,Message,Exception " /> 17 conversionPattern 18 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 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: XmlConfigurator(ConfigFile = "log4net.config")] 6 7 namespace CoderBusy.Log4Net.Tests 8 { 9 internal class Program 10 { 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。
文章标题:使用log4net将日志文件输出为csv格式
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