Idiomatic way of logging in Kotlin

Question

Kotlin doesn\'t have the same notion of static fields as used in Java. In Java, the generally accepted way of doing logging is:

public class Foo {
    privat         


        

Answer 1

First, you can add extension functions for logger creation.

inline fun  getLogger() = LoggerFactory.getLogger(T::class.java)
fun  T.getLogger() = LoggerFactory.getLogger(javaClass)

Then you will be able to create a logger using the following code.

private val logger1 = getLogger()
private val logger2 = getLogger()

Second, you can define an interface that provides a logger and its mixin implementation.

interface LoggerAware {
  val logger: Logger
}

class LoggerAwareMixin(containerClass: Class<*>) : LoggerAware {
  override val logger: Logger = LoggerFactory.getLogger(containerClass)
}

inline fun  loggerAware() = LoggerAwareMixin(T::class.java)

This interface can be used in the following way.

class SomeClass : LoggerAware by loggerAware() {
  // Now you can use a logger here.
}