§Configuring logging

Play 2.0 uses logback as its logging engine.

§Configuration logging level in application.conf

The easiest way to configure the logging level is to use the logger key in your conf/application.conf file.

Play defines a default application logger for your application, which is automatically used when you use the default Logger operations.

# Root logger:
logger=ERROR

# Logger used by the framework:
logger.play=INFO

# Logger provided to your application:
logger.application=DEBUG

The root logger configuration affects all log calls, rather than requiring custom logging levels. Additionally, if you want to enable the logging level for a specific library, you can specify it here. For example to enable TRACE log level for Spring, you could add:

logger.org.springframework=TRACE

§Configuring logback

The default is to define two appenders, one dispatched to the standard out stream, and the other to the logs/application.log file.

If you want to fully customize logback, just define a conf/logger.xml configuration file. Here is the default configuration file used by Play:

<configuration>
    
  <conversionRule conversionWord="coloredLevel" converterClass="play.api.Logger$ColoredLevel" />
  
  <appender name="FILE" class="ch.qos.logback.core.FileAppender">
     <file>${application.home}/logs/application.log</file>
     <encoder>
       <pattern>%date - [%level] - from %logger in %thread %n%message%n%xException%n</pattern>
     </encoder>
   </appender>

  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>%coloredLevel %logger{15} - %message%n%xException{5}</pattern>
    </encoder>
  </appender>
  
  <logger name="play" level="INFO" />
  <logger name="application" level="INFO" />

  <root level="ERROR">
    <appender-ref ref="STDOUT" />
    <appender-ref ref="FILE" />
  </root>
  
</configuration>

§Changing the logback configuration file

You can also specify another logback configuration file via a System property. It is particulary useful when running in production.

§Using -Dlogger.resource

Specify another loback configuration file to be loaded from the classpath:

$ start -Dlogger.resource=conf/prod-logger.xml

§Using -Dlogger.file

Specify another loback configuration file to be loaded from the file system:

$ start -Dlogger.file=/opt/prod/logger.xml

§Using -Dlogger.url

Specify another loback configuration file to be loaded from an URL:

$ start -Dlogger.url=http://conf.mycompany.com/logger.xml