Can you pull the connectionString for a log4net AdoNetAppender from elsewhere in a web.config file?

Question

I already have a db connection string in my web.config file. I scanned the log4net docs, but can't seem to find a way to use it within the log4net section of my web.config file. Is is possible to do something like this?

<connectionStrings>
    <add name="connStr" connectionString="Data Source=localhost; ..." />
</connectionStrings>

<log4net>
    <appender name="AdoNetAppender" type="log4net.Appender.AdoNetAppender">
    <connectionString connectionStringName="connStr"/>
      ...
</log4net>

score 50 · Answer 1 · answered Feb 22 '11 at 12:19

It is possible to use a DB connection string specified in web.config without creating a new class, though you would need to use log4net build that hasn't been released yet. It can be downloaded from SVN repository http://svn.apache.org/viewvc/logging/log4net/trunk/

Your config will look as follows:

<connectionStrings>
    <add name="connStr" connectionString="Data Source=localhost; ..." />
</connectionStrings>

<log4net>
    <appender name="AdoNetAppender" type="log4net.Appender.AdoNetAppender">
    <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
    <connectionStringName value="connStr" />
      ...
</log4net>

Please note that connectionType still needs to be specified.

This is now available in the latest release, 1.2.11. Works fine. — dove, Dec 22 '11 at 12:15

score 32 · Accepted Answer · answered Mar 14 '10 at 06:58

32

Create a class that extends AdoNetAppender - say, WebAppAdoNetAppender. Implement the ConnectionString property in that class, and retrieve the connection string from your web.config file in that property setter.

<log4net>
    <appender name="AdoNetAppender" type="MyApp.WebAppAdoNetAppender">
    ...

...

public class WebAppAdoNetAppender : log4net.Appender.AdoNetAppender
{
    public new string ConnectionString
    {
        get { return base.ConnectionString; }
        set { base.ConnectionString = ...   }
    }
}

answered Mar 14 '10 at 06:58

Michael Petrotta

59,888
27
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1

Stefan Egli's link indicates that a parameter doesn't yet exist. For the time being, this seems like the best way to go about it. Thanks Mr. Petrotta! – MrSharps Mar 14 '10 at 12:50
How and where would I load/call/use this class? I'm just getting started with log4net and I'm finding the documentation a little sparse. I'm running this in a Quartz.NET job, which instantiates the logger for me. How would I replace the default logger with my own subclass? Thanks. – InteXX Feb 21 '15 at 02:37

score 5 · Answer 3 · answered Mar 14 '10 at 11:30

5

fyi this will be implemented in 1.2.11 according to this. however I have no idea when they are going to release it.

answered Mar 14 '10 at 11:30

Stefan Egli

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sounds like the feature I want is forthcoming – MrSharps Mar 14 '10 at 12:49

score 5 · Answer 4 · edited May 23 '17 at 13:48

the answers above all do not work. i got another solution for this, i tried and it worked:

private static void ConfigureLog4Net()
{
    Hierarchy hierarchy = LogManager.GetRepository() as Hierarchy;
    if(hierarchy != null && hierarchy.Configured)
    {
        foreach(IAppender appender in hierarchy.GetAppenders())
        {
           if(appender is AdoNetAppender)
           {
               var adoNetAppender = (AdoNetAppender)appender;
               adoNetAppender.ConnectionString = ConfigurationManager.AppSettings["YOURCONNECTIONSTRINGKEY"].ToString();
               adoNetAppender.ActivateOptions(); //Refresh AdoNetAppenders Settings
           }
        }
    }
}

How i can use the connectionString of the current website for log4Net instead of configuring

I also couldn't get the code above to work *and this did*. For me though, I had to make sure to have a blank ConnectionString in the config: — Philip Pittle, Jan 10 '14 at 14:41

score 0 · Answer 5 · answered Nov 28 '17 at 19:19

As of 2017 (log4net 2.0.8.0), the following works:

public class MyAdoNetAppender : AdoNetAppender
{
    public MyAdoNetAppender()
    {
        ConnectionString = ...
    }
}


<appender name="AdoNetAppender" type="MyApp.MyAdoNetAppender">

(Very similar to @Michael Petrotta's answer)

Can you pull the connectionString for a log4net AdoNetAppender from elsewhere in a web.config file?

5 Answers5

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