This was added back in 1.6, and I still don't see it used very often. It seems like a more effective method of making customizable service classes than all system properties all the time (even though you can technically just make a log4j2.component.properties file to set them). I think we could use it for simple plugins that aren't log4j-core plugins (or even in log4j-core), or we could make a sort of replacement class that's similar.
If you don't already know how ServiceLoader<S> works, it looks for META-INF/services/the.full.class.name files which contain a FQCN of the implementation class. I'm not particularly sure about the order in which things are loaded, but it's certainly useful when you combine it with something like the @Order annotation we have and then sort them based on that. I know why we didn't use it for LoggerContextFactory what with the additional properties to be specified for a provider. However, I don't see why we haven't used it for other service classes. -- Matt Sicker <[email protected]>
