#9 Exception thrown when using CommonLoggingTraceListener

[Anonymous]

When System.Diagnostics.Trace to routed to send its output to the Common.Logging infrastructure using the CommonLoggingTraceListener:

app.config

<?xml version='1.0' encoding='utf-8'?>
<configuration>
<configSections>
<sectionGroup name="common">
<section name="logging" type="Common.Logging.ConfigurationSectionHandler, Common.Logging" />
</sectionGroup>
</configSections>

<common>
<logging>
<factoryAdapter type="Common.Logging.Simple.ConsoleOutLoggerFactoryAdapter, Common.Logging">
<arg key="level" value="ALL" />
<arg key="showLogName" value="true" />
<arg key="showDataTime" value="true" />
<arg key="dateTimeFormat" value="yyyy/MM/dd HH:mm:ss:fff" />
</factoryAdapter>
</logging>
</common>

<system.diagnostics>
<sharedListeners>
<add name="Diagnostics"
type="Common.Logging.Simple.CommonLoggingTraceListener, Common.Logging"
initializeData="Name=My.Namespace.Program; DefaultTraceEventType=Information; LoggerNameFormat={listenerName}">
<filter type="System.Diagnostics.EventTypeFilter" initializeData="Information"/>
</add>
</sharedListeners>
<trace>
<listeners>
<add name="Diagnostics" />
</listeners>
</trace>
</system.diagnostics>

</configuration>

an exception is thrown when trying making calls to Diagnostics.Trace:

Program.cs

static class Program
{
static int Main(string[] args)
{
var logger = LogManager.GetCurrentClassLogger();

Trace.Write("test message");
}
}

Exception details:

System.ArgumentNullException was unhandled
Message="Key cannot be null.\r\nParameter name: key"
Source="mscorlib"
ParamName="key"
StackTrace:
at System.Collections.Hashtable.get_Item(Object key)
at Common.Logging.Factory.AbstractCachingLoggerFactoryAdapter.GetLoggerInternal(String name)
at Common.Logging.Factory.AbstractCachingLoggerFactoryAdapter.GetLogger(String name)
at Common.Logging.LogManager.GetLogger(String name)
at Common.Logging.Simple.CommonLoggingTraceListener.Log(TraceEventType eventType, String source, Int32 id, String format, Object[] args)
at Common.Logging.Simple.CommonLoggingTraceListener.Write(String message)
at System.Diagnostics.TraceInternal.Write(String message)
at My.Namespace.Program.Main(String[] args) in Program.cs:line 20
at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:

The exception occurs when you call Trace.Write without a "cateogry" param. The following will work:

Program.cs

static class Program
{
static int Main(string[] args)
{
var logger = LogManager.GetCurrentClassLogger();

Trace.Write("test message", "test category");
}
}

The source of the problem is CommonLoggingTraceListener.Log, line 178.

If the "source" param is null, the proper logger name will not be created, causing us to send a null param to the GetLogger method:

ILog log = LogManager.GetLogger(source);

The fix is, instead of:

178 if (!string.IsNullOrEmpty(source))
179 {
180 source = this.LoggerNameFormat.Replace("{listenerName}", this.Name).Replace("{sourceName}", source);
181 }

we do:

source = this.LoggerNameFormat.Replace("{listenerName}", this.Name);

if (!string.IsNullOrEmpty(source))
{
source = source.Replace("{sourceName}", source);
}

[Anonymous]

[Anonymous]

Another alternative solution might be to not pass null into the Log method from it's usages:

CommonLoggingTraceListener.cs

267 /// <summary>
268 /// Writes message to logger provided by <see cref="LogManager.GetLogger(string)"/>.
269 /// </summary>
270 public override void Write(string message)
271 {
272 if (((this.Filter == null) || this.Filter.ShouldTrace(null, this.Name, this.DefaultTraceEventType, 0, null, null, null, null)))
273 {
274 Log(this.DefaultTraceEventType, null, 0, message);
275 }
276 }

Instead of the null param on line 274 we can do something like "uncategorized".

[Mark Pollack]

Thanks so much for reporting this!

[Erich Eichinger]

fixed by simple converting a <null> source to string.Empty before formatting the loggername

[Anonymous]

Hi Mark, Erich,
Thank you for the quick fix!

I now use CommonLogging in all my projects, and I love it. Thank you so much for the community contribution!

Sorry for the late response. For some reason I didn't get notification on any updates on this.

Best regards,

Martin