How to use Logback directly without going through SLF4J

Question

I'm trying to tweak some logback functionality (custom Appenders and the like). In order to test it I would like to configure Logback and call its logging methods directly without going through sl4j.

The reason for this weird requirement is to be able to test logback functionality in an environment where also other SLF4J bridges are available.

So I want to do the stuff described when invoking JoranConfigurator directly without a reference to SLF4J.

Answer 1

There is a way to find out.

Here's the example how you can configure LOGBack

// Here we create context
LoggerContext loggerContext = new LoggerContext();
// Initializer is used to enrich context with details
ContextInitializer contextInitializer = new ContextInitializer(loggerContext);
try {
    // Get a configuration file from classpath
    URL configurationUrl = Thread.currentThread().getContextClassLoader().getResource("custom-logback-configuration.xml");
    if (configurationUrl == null) {
        throw new IllegalStateException("Unable to find custom logback configuration file");
    }
    // Ask context initializer to load configuration into context
    contextInitializer.configureByResource(configurationUrl);
    // Here we get logger from context
    logger = loggerContext.getLogger(LogReporter.class);
} catch (JoranException e) {
    throw new RuntimeException("Unable to configure logger", e);
}

In general if you want to know how any SLF4J backend works, you may just to look at org.slf4j.impl.StaticLoggerBinder class source from that backend.

Answer 2

Unfortunately, I don't think its possible. If you take a look at the Logback Logger source (or other classes) you will see it depends on slf4j.

This is not nice, imho, as logback should be unaware of slf4j.