How to change maven logging level to display only warning and errors?

Question

I want to prevent maven from displaying INFO messages, I want to see only WARNINGS and ERRORS (if any).

How can I achieve this, preferably by changing the command line that calls maven?

Answer 1

Answering your question

I made a small investigation because I am also interested in the solution.

Maven command line verbosity options

According to http://books.sonatype.com/mvnref-book/reference/running-sect-options.html#running-sect-verbose-option

• -e for error
• -X for debug
• -q for only error

Maven logging config file

Currently maven 3.1.x uses SLF4J to log to the System.out . You can modify the logging settings at the file:

${MAVEN_HOME}/conf/logging/simplelogger.properties

According to the page : http://maven.apache.org/maven-logging.html

Command line setup

I think you should be able to setup the default Log level of the simple logger via a command line parameter, like this:

$ mvn clean package -Dorg.slf4j.simpleLogger.defaultLogLevel=debug

But I could not get it to work. I guess the only problem with this is, maven picks up the default level from the config file on the classpath. I also tried a couple of other settings via System.properties, but all of them were unsuccessful.

Appendix

You can find the source of slf4j on github here : slf4j github

The source of the simplelogger here : slf4j/jcl-over-slf4j/src/main/java/org/apache/commons/logging/impl/SimpleLog.java

The plexus loader loads the simplelogger.properties.