Run Logback in Debug

Question

I've recently switched from log4j to logback and am wondering if there is an easy way to run logback in debug mode, similar to log4j's log4j.debug property. I need to see where it is picking up my logback.xml from.

The docs mention using a StatusPrinter to print out logback's internal status, but that would require code changes.

Answer 1

[EDIT]

This has been fixed in Logback 1.0.4. You can now use -Dlogback.debug=true to enable debugging of the logback setup.

-- Old Answer --

Unfortunately, there is no way to enable debugging via a System property. You have to use <configuration debug="true"> in the logback.xml. Please submit a feature request.

Answer 2

This is how I do it. I set a system property called 'log.level', then I reference it in logback.xml.

Edit: The downside is that you MUST have 'log.level' always set. The way I deal with this is to check in my main method and set it to INFO if not already set, be sure to do this before you first logging calls. Then I can override on the command line, and have a sensible default.

Here is how it looks in my logback.xml:

<configuration>     <logger name="com.mycompany.project" level="${log.level}" />     <logger name="httpclient" level="WARN" />     <logger name="org.apache" level="WARN" />     <logger name="org.hibernate" level="WARN" />     <logger name="org.hibernate.cfg.AnnotationBinder" level="WARN" />     <logger name="org.hibernate.cfg.annotations" level="WARN" />     <logger name="org.quartz" level="WARN" />     <logger name="org.springframework" level="WARN" />      <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">         <encoder>             <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%-16thread] %-5level %-35.35logger{30} - %msg%n</pattern>         </encoder>     </appender>     <root level="${log.level:-INFO}">         <appender-ref ref="STDOUT" />     </root> </configuration>