Log4j logging in maven project

Question

I am running my Selenium Automation tests using Maven. From time of execution till end I see so many logs.

I came to know with this code that only .info warnings and .warn goes to console and .debug doesn't.

public static void main(String[] args) {
        Logger log = LogManager.getLogger();
        log.debug("its a debug message");
        log.info("its a info message");
        log.warn("its a warning message");
    }

Output:

2015-12-24 13:58:21,166 ERROR Logger contains an invalid element or attribute "append"
[INFO ] 2015-12-24 13:58:21.245 [main] DebuggerTest - its a info message
[WARN ] 2015-12-24 13:58:21.247 [main] DebuggerTest - its a warning message

Now I want to pass on a variable in along with my mvn command that will switch on/off any logs in console.

Something like: mvn test --debugging -false So that logs can be seen in generated logs file but not in console.

More info: I want something like given here: How to initialize log4j properly?

here user "MATH" advised to use : Logger.getRootLogger().setLevel(Level.WARN); if don't want to see debug logs

I want to enable/disable this from mvn command line.

More info 2:

this is how my log4j2.xml looks:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Properties>
        <Property name="log-path">logs</Property>
    </Properties>
    <Appenders>
        <Console name="console-log" target="SYSTEM_OUT">
            <PatternLayout pattern="[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n"/>
        </Console>
        <RollingFile name="trace-log" fileName="${log-path}/rnf-info.log"
                     filePattern="${log-path}/rnf-trace-%d{yyyy-MM-dd}.log" append="false">
            <PatternLayout>
                <pattern>[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n</pattern>
            </PatternLayout>
            <Policies>
                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
            </Policies>
        </RollingFile>
        <RollingFile name="debug-log" fileName="${log-path}/rnf-debug.log"
                     filePattern="${log-path}/rnf-debug-%d{yyyy-MM-dd}.log" append="false">
            <PatternLayout>
                <pattern>[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n</pattern>
            </PatternLayout>
            <Policies>
                <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
            </Policies>
        </RollingFile>
    </Appenders>
    <Loggers>
        <Logger name="com.rnf" level="debug" additivity="false" append="false">
            <appender-ref ref="trace-log" level="info"/>
            <appender-ref ref="debug-log" level="debug"/>
        </Logger>
        <Root level="info" additivity="false">
            <AppenderRef ref="console-log"/>
        </Root>
    </Loggers>
</Configuration>

Answer 1

What you can try to use are variables

log4j2 configuration

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
    <Properties>
        <Property name="LEVEL">WARN</Property> <!-- default value -->
    </Properties>
    <Appenders>
        <Console name="Console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
        </Console>
    </Appenders>
    <Loggers>
        <Root level="${sys:LEVEL}">
            <AppenderRef ref="Console" />
        </Root>
    </Loggers>
</Configuration>

and to change the default value from WARN to DEBUG you can use

-DLEVEL=DEBUG

Edit:

In your configuration the level for console is fixed - static, set to INFO, but you want to have a dynamic behavior.

You need to add another property

<Properties>
    <Property name="log-path">logs</Property>
    <Property name="LEVEL">WARN</Property> <!-- default value -->
</Properties>

In which I set WARN as a default level, so by default, there will be less messages in console.

Then I'm referencing the property in Root logger configuration ${sys:LEVEL}

<Root level="${sys:LEVEL}">

but it can be specified from command line as standard JVM parameter -D....

So if you want more messages in console, you will run mvn test -DLEVEL=DEBUG

Answer 2

I think you could use -Dlog4j.configuration=<path> to set the configuration of the logger to whatever you want directly on command line.

See documentation here: http://logging.apache.org/log4j/1.2/manual.html