How to log MethodName when wrapping Log4net?

Question

I have wrapped Log4net in a static wrapper and want to log

loggingEvent.LocationInformation.MethodName
loggingEvent.LocationInformation.ClassName

However all I get is the name of my wrapper.

How can I log that info using a forwardingappender and a static wrapper class like

Logger.Debug("Logging to Debug");
Logger.Info("Logging to Info");
Logger.Warn("Logging to Warn");
Logger.Error(ex);
Logger.Fatal(ex);

Answer 1

Well the error was somewhere in my appender but for completeness ill include the answer to the best of my knowledge:

the Facade you need should wrap ILogger and NOT ILog

 public static class Logger
 {
    private readonly static Type ThisDeclaringType = typeof(Logger);
    private static readonly ILogger defaultLogger;

    static Logger()
    {
      defaultLogger =
        LoggerManager.GetLogger(Assembly.GetCallingAssembly(),"MyDefaultLoggger");

...

    public static void Info(string message)
    {
        if (defaultLogger.IsEnabledFor(infoLevel))
        {
            defaultLogger.Log(typeof(Logger), infoLevel, message, null);
        }
    }

Answer 2

What about the %M and %C variables? http://logging.apache.org/log4net/log4net-1.2.11/release/sdk/log4net.Layout.PatternLayout.html

Usage, something like:

<layout type="log4net.Layout.PatternLayout">
  <conversionPattern value="%date [%thread] %-5level %logger [%M %C] - %message%newline" />
</layout>

Doesn't that do what you are after?

Answer 3

I would simply use something like %stacktrace{2} as a conversion pattern.

Example of output:

MyNamespace.ClassName.Method > Common.Log.Warning

where MyNamespace.ClassName.Method is a method that is calling my wrapper and Common.Log.Warning is a method of the wrapper class.

Conversion patterns can be found here.

Answer 4

Just declare your log variable like this...

private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

Then you can use it normaly.

Answer 5

This post helped me work out how to write my own wrapper so in return, thought you might like my complete class to wrap the logger which seems to work quite nicely and actually takes just over half as much time as using an ILog directly!

All that's required is the appropriate xml to set up the logging in the config file and

[assembly: log4net.Config.XmlConfigurator(Watch = true)] 

in your AssemblyInfo.cs and it should work easily.

One note: I'm using Log4NetDash with a seriously simple set-up so have cheated and put some information in the wrong fields (eg stack trace in Domain field), this still works for me as I don't care where the information is shown but you might want to fix this if you're setting stuff up properly if you spare time!

using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Reflection;
using System.Threading;
using log4net;
using log4net.Core;

namespace Utility
{
    public class Logger
    {
        static Logger()
        {
            LogManager.GetLogger(typeof(Logger));
        }

        public static void Debug(string message, params object[] parameters)
        {
            Log(message, Level.Debug, null, parameters);
        }

        public static void Info(string message, params object[] parameters)
        {
            Log(message, Level.Info, null, parameters);
        }

        public static void Warn(string message, params object[] parameters)
        {
            Log(message, Level.Warn, null, parameters);
        }

        public static void Error(string message, params object[] parameters)
        {
            Error(message, null, parameters);
        }

        public static void Error(Exception exception)
        {
            if (exception==null)
                return;
            Error(exception.Message, exception);
        }

        public static void Error(string message, Exception exception, params object[] parameters)
        {
            string exceptionStack = "";

            if (exception != null)
            {
                exceptionStack = exception.GetType().Name + " : " + exception.Message + Environment.NewLine;
                Exception loopException = exception;
                while (loopException.InnerException != null)
                {
                    loopException = loopException.InnerException;
                    exceptionStack += loopException.GetType().Name + " : " + loopException.Message + Environment.NewLine;
                }
            }

            Log(message, Level.Error, exceptionStack, parameters);
        }



        private static void Log(string message, Level logLevel, string exceptionMessage, params object[] parameters)
        {
            BackgroundWorker worker = new BackgroundWorker();
            worker.DoWork += LogEvent;
            worker.RunWorkerAsync(new LogMessageSpec
                                      {
                                          ExceptionMessage = exceptionMessage,
                                          LogLevel = logLevel,
                                          Message = message,
                                          Parameters = parameters,
                                          Stack = new StackTrace(),
                                          LogTime = DateTime.Now
                                      });
        }

        private static void LogEvent(object sender, DoWorkEventArgs e)
        {
            try
            {
                LogMessageSpec messageSpec = (LogMessageSpec) e.Argument;

                StackFrame frame = messageSpec.Stack.GetFrame(2);
                MethodBase method = frame.GetMethod();
                Type reflectedType = method.ReflectedType;

                ILogger log = LoggerManager.GetLogger(reflectedType.Assembly, reflectedType);
                Level currenLoggingLevel = ((log4net.Repository.Hierarchy.Logger) log).Parent.Level;

                if (messageSpec.LogLevel<currenLoggingLevel)
                    return;

                messageSpec.Message = string.Format(messageSpec.Message, messageSpec.Parameters);
                string stackTrace = "";
                StackFrame[] frames = messageSpec.Stack.GetFrames();
                if (frames != null)
                {
                    foreach (StackFrame tempFrame in frames)
                    {

                        MethodBase tempMethod = tempFrame.GetMethod();
                        stackTrace += tempMethod.Name + Environment.NewLine;
                    }
                }
                string userName = Thread.CurrentPrincipal.Identity.Name;
                LoggingEventData evdat = new LoggingEventData
                                             {
                                                 Domain = stackTrace,
                                                 Identity = userName,
                                                 Level = messageSpec.LogLevel,
                                                 LocationInfo = new LocationInfo(reflectedType.FullName,
                                                                                 method.Name,
                                                                                 frame.GetFileName(),
                                                                                 frame.GetFileLineNumber().ToString()),
                                                 LoggerName = reflectedType.Name,
                                                 Message = messageSpec.Message,
                                                 TimeStamp = messageSpec.LogTime,
                                                 UserName = userName,
                                                 ExceptionString = messageSpec.ExceptionMessage
                                             };
                log.Log(new LoggingEvent(evdat));
            }
            catch (Exception)
            {}//don't throw exceptions on background thread especially about logging!
        }

        private class LogMessageSpec
        {
            public StackTrace Stack { get; set; }
            public string Message { get; set; }
            public Level LogLevel { get; set; }
            public string ExceptionMessage { get; set; }
            public object[] Parameters { get; set; }
            public DateTime LogTime { get; set; }
        }
    }
}

Answer 6

How about C#4.5 feature callerinfo - http://msdn.microsoft.com/en-us/library/system.runtime.compilerservices.callermembernameattribute.aspx

Answer 7

I implemented the following solution for this (.Net framework 4.5+) : the log4net wrapper methods (e.g. Info, Warn, Error) could make use of CallerMemberName and CallerFilePath to fetch the class and method name of the code from where the logs are being called. You can then aggregate these into a custom log4net property.

Feel free to use your log4net own wrapper implementation, the only important things here are: the signature of the Info and Error methods, and the implementation of the GetLogger method.

The 'memberName' and 'sourceFilePath' args should never be specified when calling the Logger.Info or Logger.Error methods, they are auto-filled-in by .Net.

public static class Logger
{
    private class LogSingletonWrapper
    {
        public ILog Log { get; set; }
        public LogSingletonWrapper()
        {
            Log = LogManager.GetLogger(GetType());
        }
    }

    private static readonly Lazy<LogSingletonWrapper> _logger = new Lazy<LogSingletonWrapper>();

    public static void Info(string message, [CallerMemberName] string memberName = "", [CallerFilePath] string sourceFilePath = "") 
        => GetLogger(memberName, sourceFilePath).Info(message);
    
    public static void Error(string message,Exception ex, [CallerMemberName] string memberName = "", [CallerFilePath] string sourceFilePath = "") 
        => GetLogger(memberName, sourceFilePath).Error(message, ex);

    private static ILog GetLogger(string memberName, string sourceFilePath)
    {
        var classname = sourceFilePath.Split('\\').Last().Split('.').First();
        log4net.ThreadContext.Properties["Source"] = $"{classname}.{memberName.Replace(".", "")}";
        return _logger.Value.Log;
    }
}

Then you would could use a log conversion pattern like this in your .config file :

<conversionPattern value="[%level][%date][Thd%thread: %property{Source}][Message: %message]%newline" />

This would result in logs looking like this:

[INFO][2019-07-03 16:42:00,936][Thd1: Application.Start][Message: The application is starting up ...]

[ERROR][2019-07-03 16:42:44,145][Thd6: DataProcessor.ProcessDataBatch][Message: Attempted to divide by zero.]

The following methods were called in the above example: the Start method of the Application class, and the ProcessDataBatch method of the DataProcessor class.

Answer 8

The only thing I can think of doing (as I dont currently use log4net) is to request a stacktrace(new StackTrace), and go back a frame to get the info you need. However, I am unsure of the runtime performance impact of this.

Answer 9

I will just write more code of the correct answer of Claus

In the wrapper class

public static class Logger
{
   private static readonly ILogger DefaultLogger;

   static Logger()
   {
      defaultLogger = LoggerManager.GetLogger(Assembly.GetCallingAssembly(), "MyDefaultLoggger"); // MyDefaultLoggger is the name of Logger
   }

  public static void LogError(object message)
  {
      Level errorLevel = Level.Error;
      if (DefaultLogger.IsEnabledFor(errorLevel))
      {
          DefaultLogger.Log(typeof(Logger), errorLevel, message, null);
      }
  }

  public static void LogError(object message, Exception exception)
  {
      Level errorLevel = Level.Error;
      if (DefaultLogger.IsEnabledFor(errorLevel))
      {
          DefaultLogger.Log(typeof(Logger), errorLevel, message, exception);
      }
  }

and so on for the rest of methods.

in web.config or app.config log4net.Layout.PatternLayout you can use some Conversion Patterns like:

%location %method %line

<layout type="log4net.Layout.PatternLayout">
    <conversionPattern value="%date{dd/MM/yyyy hh:mm:ss.fff tt} [%thread] %level %logger [%location %method %line] [%C %M] - %newline%message%newline%exception"/>
  </layout>

Answer 10

Click here to learn how to implement log4net in .NET Core 2.2

The following steps are taken from the above link, and break down how to add log4net to a .NET Core 2.2 project.

First, run the following command in the Package-Manager console:

Install-Package Log4Net_Logging -Version 1.0.0

Then add a log4net.config with the following information (please edit it to match your set up):

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
  </configSections>
  <log4net>
    <appender name="FileAppender" type="log4net.Appender.FileAppender">
      <file value="logfile.log" />
      <appendToFile value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%d [%t] %-5p - %m%n" />
      </layout>
    </appender>
    <root>
      <!--LogLevel: OFF, FATAL, ERROR, WARN, INFO, DEBUG, ALL -->
      <level value="ALL" />
      <appender-ref ref="FileAppender" />
    </root>
  </log4net>
</configuration>

Then, add the following code into a controller (this is an example, please edit it before adding it to your controller):

public ValuesController()
{
    LogFourNet.SetUp(Assembly.GetEntryAssembly(), "log4net.config");
}
// GET api/values
[HttpGet]
public ActionResult<IEnumerable<string>> Get()
{
    LogFourNet.Info(this, "This is Info logging");
    LogFourNet.Debug(this, "This is Debug logging");
    LogFourNet.Error(this, "This is Error logging");    
    return new string[] { "value1", "value2" };
}

Then call the relevant controller action (using the above example, call /Values/Get with an HTTP GET), and you will receive the output matching the following:

2019-06-05 19:58:45,103 [9] INFO-[Log4NetLogging_Project.Controllers.ValuesController.Get:23] - This is Info logging