Complete "Scala Logging" Example

Question

I'm trying to use Typesafe's Scala Logging but couldn't get it to print any debug message. I expect Scala Logging to print debug message to the default screen but it doesn't work. A complete example would be very helpful or specific advise what to change would be great too. I use Scala 2.11. Here is what I did:

1. I added the dependency to build.sbt:

   libraryDependencies += "com.typesafe.scala-logging" %% "scala-logging" % "3.1.0" 

   Even though I'm not sure if this is required, I added the following line but it didn't do any difference:

   libraryDependencies += "com.typesafe.scala-logging" % "scala-logging-slf4j_2.11" % "2.1.2" 

2. This is how my class looks like basically:

   import com.typesafe.scalalogging._  class MyClass extends LazyLogging {   // ...   logger.debug("Here goes my debug message.")   // ... } 

3. I discovered the file ./src/main/resources/logback.xml but am not sure which module installed it and if its relevant. I changed the log level to "debug" without effect.

   <configuration>    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">     <!-- encoders are assigned the type          ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->     <encoder>       <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>     </encoder>   </appender>    <logger name="scala.slick" level="DEBUG"/>    <root level="debug">     <appender-ref ref="STDOUT" />   </root> </configuration> 

Answer 1

For those who're still struggling for how to make your scala-logging work in your sbt project. They just need to follow these steps:

1. Add these two dependencies in your build.sbt:

   libraryDependencies += "com.typesafe.scala-logging" %% "scala-logging" % "3.1.0" libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.1.2" 

2. Create a file logback.xml in your /src/main/resources/ and paste below mentioned content in that file.

   <configuration>     <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">         <encoder>             <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>         </encoder>     </appender>      <appender name="FILE" class="ch.qos.logback.core.FileAppender">         <!-- path to your log file, where you want to store logs -->         <file>/Users/yourusername/test.log</file>         <append>false</append>         <encoder>             <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>         </encoder>     </appender>      <root level="debug">         <appender-ref ref="STDOUT" />         <appender-ref ref="FILE" />     </root> </configuration> 

3. Extend your Scala class or object with trait LazyLogging:

   import com.typesafe.scalalogging.slf4j.LazyLogging class MyClass extends LazyLogging {   logger.debug("This is very convenient ;-)") } 

4. It's done.

P.S: Only a side note that logger is already a member of trait LazyLogging so you don't need to create it (as shown in above example)