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

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.

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Edit: this answer was from 2013, there are probably better ways to do this now, please consider the other answers.

Linux:

mvn validate clean install | egrep -v "(^\[INFO\])"

or

mvn validate clean install | egrep -v "(^\[INFO\]|^\[DEBUG\])"

Windows:

mvn validate clean install | findstr /V /R "^\[INFO\] ^\[DEBUG\]"

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You can achieve this with MAVEN_OPTS, for example
MAVEN_OPTS=-Dorg.slf4j.simpleLogger.defaultLogLevel=warn mvn clean

Rather than putting the system property directly on the command line. (At least for maven 3.3.1.)

Consider using ~/.mavenrc for setting MAVEN_OPTS if you would like logging changed for your login across all maven invocations.

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If you are using Logback, just put this logback-test.xml file into src/test/resources directory:

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

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you can achieve this by using below in the commandline itself

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

e.g :

mvn test -X -DsomeProperties='SomeValue' [For Debug level Logs] mvn test -e -DsomeProperties='SomeValue' [For Error level Logs] mvn test -q -DsomeProperties='SomeValue' [For Only Error Logs]

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The simplest way is to upgrade to Maven 3.3.1 or higher to take advantage of the ${maven.projectBasedir}/.mvn/jvm.config support.

Then you can use any options from Maven's SL4FJ's SimpleLogger support to configure all loggers or particular loggers. For example, here is a how to make all warning at warn level, except for a the PMD which is configured to log at error:

cat .mvn/jvm.config
-Dorg.slf4j.simpleLogger.defaultLogLevel=warn -Dorg.slf4j.simpleLogger.log.net.sourceforge.pmd=error

See here for more details on logging with Maven.

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Unfortunately, even with maven 3 the only way to do that is to patch source code.

Here is short instruction how to do that.

Clone or fork Maven 3 repo: "git clone https://github.com/apache/maven-3.git"

Edit org.apache.maven.cli.MavenCli#logging, and change

cliRequest.request.setLoggingLevel( MavenExecutionRequest.LOGGING_LEVEL_INFO );

to

cliRequest.request.setLoggingLevel( MavenExecutionRequest.LOGGING_LEVEL_WARN );

In current snapshot version it's at line 270

Then just run "mvn install", your new maven distro will be located in "apache-maven\target\" folder

See this diff for the reference: https://github.com/ushkinaz/maven-3/commit/cc079aa75ca8c82658c7ff53f18c6caaa32d2131

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Go to simplelogger.properties in ${MAVEN_HOME}/conf/logging/ and set the following properties:

org.slf4j.simpleLogger.defaultLogLevel=warn
org.slf4j.simpleLogger.log.Sisu=warn
org.slf4j.simpleLogger.warnLevelString=warn

And beware: warn, not warning

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I have noticed when using the 2.20.1 version of the maven sunfire plugin, all warnings are written down to a dumpstream file. e.g. /myproject/target/surefire-reports/2017-11-11T23-02-19_850.dumpstream

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Changing the info to error in simplelogging.properties file will help in achieving your requirement.

Just change the value of the below line

org.slf4j.simpleLogger.defaultLogLevel=info 

to

org.slf4j.simpleLogger.defaultLogLevel=error

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In Debian this worked for me like a charm to change the log level for Maven 3.6 at runtime without having to change the simplelogger.properties file:

MAVEN_OPTS='-Dorg.slf4j.simpleLogger.defaultLogLevel=error' mvn test

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