slf4j-net-commons-logging

Pipe SLF4J logs in an IKVM'd jar through to https://github.com/net-commons/common-logging

Control the Java logging emitted by your IKVM'd dlls, coercing them into using the logging infrastructure you have in place on the .NET side.

This repo contains both the Java code, and the dot NET artifacts for publishing to nuget.

Motive

By now, many Java libraries use slf4j for logging, so the user of the library can use their preferred logging framework to display the logs. Ideally, system-wide logging can be configured in a single place.

Common.Logging is a similar idea for .NET: http://netcommon.sourceforge.net/

It supports Log4Net, NLog, System.Console, System.Diagnostics.Trace etc

Wouldn't it be nice if your slf4j logs could be routed to the preferred .NET logging implementation?

I thought so.. and it turns out that binding Common.Logging to slf4j is pretty straightforward; see https://github.com/plutext/slf4j-net-commons-logging/tree/master/src/main/java

Users

Note: this project will only help if the IKVM'd jars use slf4j, as opposed to a hard coded dependency on log4j, JUL, Commons-Logging etc.

To try it out, you need 3 DLLs:

• IKVM'd slf4j-api
• IKVM'd version of the above source
• Common.Logging

Then just follow the Common.Logging doco to configure: http://netcommon.sourceforge.net/documentation.html

You can get the 3 DLLs from NuGet:

• https://www.nuget.org/packages/slf4j-api/1.7.5
• https://www.nuget.org/packages/slf4j-NetCommonLogging/1.0.0
• https://www.nuget.org/packages/Common.Logging/

or if you aren't using NuGet: https://github.com/plutext/slf4j-net-commons-logging/tree/master/dotNET/lib/net20 and https://github.com/net-commons/common-logging/downloads

As Jeroen has explained, when there is no main assembly (eg in an ASP.NET application), the IKVM class loader can't find your assembly when the code is trying to dynamically load a class. So you'll want to add:

            ikvm.runtime.Startup.addBootClassPathAssembly(
                System.Reflection.Assembly.GetAssembly(
                    typeof(org.slf4j.impl.StaticLoggerBinder)));
                    
            ikvm.runtime.Startup.addBootClassPathAssembly(
                System.Reflection.Assembly.GetAssembly(
                    typeof(org.slf4j.LoggerFactory)));

If you are using docx4j.NET, you should also add:

            ikvm.runtime.Startup.addBootClassPathAssembly(
                System.Reflection.Assembly.GetAssembly(
                    typeof(org.docx4j.jaxb.Context)));                    

Developers

The source code here is Java, not C#/.NET. So you'll need a Java dev env.

Compile using ant, target 'dist.NET'.

That'll write dlls to dotNET/lib/net20