Scala Logging

Scala Logging is a convenient and performant logging library wrapping SLF4J.

It's convenient, because you can simply call log methods without checking whether the respective log level is enabled:

logger.debug(s"Some $expensive message!")

It's performant, because thanks to Scala macros the check-enabled-idiom is applied, just like writing this more involved code:

if (logger.isDebugEnabled) logger.debug(s"Some $expensive message!")

Prerequisites

  • Java 6 or higher
  • Scala 2.11
  • Logging backend compatible with SLF4J, e.g. Logback

If you are looking for a version compatible with Scala 2.10, check out Scala Logging 2.x.

Getting Scala Logging

Scala Logging is published to Sonatype OSS and Maven Central:

  • Group id / organization: com.typesafe.scala-logging
  • Artifact id / name: scala-logging
  • Latest version is 3.0.0

The following example shows how to add a dependency to the latest version of Scala Logging to your sbt build definition:

libraryDependencies += "com.typesafe.scala-logging" %% "scala-logging" % "3.0.0"

Using Scala Logging

The Logger class from the com.typesafe.scalalogging package wraps an underlying SLF4J logger. Hence, in order to create a Logger, you have to pass a SLF4J logger to the apply factory method defined in the Logger companion object:

val logger = Logger(LoggerFactory.getLogger("name"))

The LazyLogging and StrictLogging traits from the com.typesafe.scalalogging package define the logger member as a lazy or strict value respectively. In both cases the underlying SLF4J logger is named according to the class into which these traits are mixed:

class MyClass extends LazyLogging {
  logger.debug("This is very convenient ;-)")
}

Contribution policy

Contributions via GitHub pull requests are gladly accepted from their original author. Before we can accept pull requests, you will need to agree to the Typesafe Contributor License Agreement online, using your GitHub account.

License

This code is open source software licensed under the Apache 2.0 License.