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Anko is an Android library that uses Kotlin and makes Android development easier with the help of extension functions. It provides Anko-logger, which you can use if you don’t want to write your own logger. It is included in anko-commons, which also has a lot of interesting things to make it worthwhile to include it in your Android projects that use Kotlin.

In Anko, a standard implementation of logger will look something like this:

class SomeActivity : Activity(), AnkoLogger {
   private fun someMethod() {
       info("London is the capital of Great Britain")
       debug(5) // .toString() method will be executed
       warn(null) // "null" will be printed
   }
}

As you can see, you just need to implement AnkoLogger and you are done.

Each method has two versions: plain and lazy (inlined):

info("String " + "concatenation")

info { "String " + "concatenation" }

The lambda result will be calculated only if Log.isLoggable(tag, Log.INFO) is true.