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Error while reading system.properties variable in log4j2.xml

My log4j2.xml looks like -
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Appenders>
<Console name="LogToConsole" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<RollingFile name="RollingFile" fileName="logs/${sys:logfilename}.log" filePattern="logs/${sys:logfilename}.log">
<Policies>
<OnStartupTriggeringPolicy/>
</Policies>
<DefaultRolloverStrategy fileIndex="max" max="10"/>
<PatternLayout pattern="[%d{dd/MMM/yyyy HH:mm:ss.SSS}]> %-5p - %m%n"/>
</RollingFile>
<Async name="ASYNC">
<AppenderRef ref="RollingFile"/>
</Async>
</Appenders>
<Loggers>
<root level="debug">
<appender-ref ref="LogToConsole" level="info"/>
<appender-ref ref="RollingFile" level="debug"/>
</root>
</Loggers>
</Configuration>
I am setting system.properties variable like -
public static void main(String[] args) throws IOException {
---some code
System.setProperty("logfilename", "a_cool_logname");
---somecode
}
But when i run with this set up I get error like -
ERROR Unable to create file logs/${sys:logfilename}.log java.io.IOException: The filename, directory name, or volume label syntax is incorrect
I also tried RollingFile name="RollingFile" fileName="${main:-logfilename}.log" filePattern="${main:-logfilename}.log"> in this case log file is getting generated with name logfilename.log . Its not substituting the value set up in main method.
Any idea, where am I making a mistake?
Kind Regards,
Abhi

Log4j does not print to console nor write to file

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
public class AzulMain {
private static final Logger LOGGER = LogManager.getLogger(AzulMain.class.getName());
public static void main(String[] args){
LOGGER.info("Maybe my first Logger works?");
}
}
The imports work fine. I use these jar-files:
log4j-1.2-api-2.17.2.jar
log4j-api.2.17.2.jar
log4j-core-2.17.2.jar
And this is how my XML-file (log4j2.xml) looks. It is in the same folder as my AzulMain:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn">
<Properties>
<Property name="log-path">log/${date:yyyy-MM-dd HH-mm-ss-SSS}</Property>
<Property name="archive">${log-path}/archive</Property>
</Properties>
<Appenders>
<Console name="Console-Appender" target="SYSTEM_OUT">
<PatternLayout>
<pattern>
%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n
</pattern>
</PatternLayout>
</Console>
<File name="File-Appender-AzulMain" fileName="${log-path}/Azul.log">
<PatternLayout>
<pattern>
%d{yyyy-MM-dd HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n
</pattern>
</PatternLayout>
</File>
<RollingFile name="RollingFile-Appender"
fileName="${log-path}/rollingfile.log"
filePattern="${archive}/rollingfile.log.%d{yyyy-MM-dd#HH-mm}.gz">
<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n"/>
<Policies>
<TimeBasedTriggeringPolicy/>
<SizeBasedTriggeringPolicy size="30 MB"/>
</Policies>
<DefaultRolloverStrategy max="30"/>
</RollingFile>
</Appenders>
<Loggers>
<Logger name="AzulMain" level="trace" additivity="false">
<AppenderRef ref="File-Appender-AzulMain" level="all"/>
<AppenderRef ref="Console-Appender" level="info"/>
</Logger>
<Root level="debug" additivity="false">
<AppenderRef ref="Console-Appender"/>
</Root>
</Loggers>
</Configuration>
When I use JavaUtilLogger everything works quite fine so far, I can make it create a file and print to console, however, with log4j nothing works.
I tested deleting the XML file and adding BasicConfigurator.configure() into my main-method, but it still didn't work. If I start my main-method all I get is:
Process finished with exit code 0
What is strange to me is that when I use the command java -Dlog4j.debug -cp AzulMain, it does not show me my configuration as I would expect it, but just what seems to be a very generic help message.
It is my first time, I am using a logger. Does anyone know what the problem might be?
Update:
This helped me as a first step:
BasicConfigurator replacement in log4j2
I deleted the XML-file and used the new
Configurator.initialize(new DefaultConfiguration());
Configurator.setRootLevel(Level.INFO);
And now it works at least in so far as it prints to the console. However, I am still not able to make it use the log4j2.xml file. I tried naming it log4j2-test.xml, too. (Source) It did not make a difference.

Now it works. This is how I did it.
I set up a new project, with just a main-class and added a new xml-file with a file logger only at first, then added a logger to the console, too. I deleted cache in IntelliJ and deleted the Configurator-lines in the code.
This is the new XML-file log4j2.xml that made it work:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn">
<Properties>
<Property name="basePath">log/${date:yyyy-MM-dd HH-mm-ss-SSS}</Property>
</Properties>
<!-- File Logger -->
<Appenders>
<!-- Console appender configuration -->
<Console name="Console-Appender" target="SYSTEM_OUT">
<PatternLayout>
<pattern>
%d{HH:mm:ss.SSS} %-5level %class{36} %L %M - %msg%xEx%n
</pattern>>
</PatternLayout>
</Console>
<RollingFile name="fileLogger"
fileName="${basePath}/Azul.log"
filePattern="${basePath}/app-%d{yyyy-MM-dd}.log">
<PatternLayout>
<pattern>[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n
</pattern>
</PatternLayout>
<Policies>
<TimeBasedTriggeringPolicy interval="1" modulate="true" />
<SizeBasedTriggeringPolicy size="10MB" />
</Policies>
<!-- Max 10 files will be created everyday -->
<DefaultRolloverStrategy max="10">
<Delete basePath="${basePath}" maxDepth="10">
<!-- Delete all files older than 30 days -->
<IfLastModified age="30d" />
</Delete>
</DefaultRolloverStrategy>
</RollingFile>
</Appenders>
<Loggers>
<Root level="info" additivity="false">
<appender-ref ref="fileLogger" />
<appender-ref ref="Console-Appender" level="info"/>
</Root>
</Loggers>
</Configuration>
It seems to me to have been a mistake somewhere in the xml-file that I just couldn't figure out where it is.

log4j - write to file name as the logger name

I am trying to write my log into different files depending on the logger name...
is it even possible?
how I can use the logger name in the target file name?
this is the XML file I use:
<Configuration status="info">
<Properties>
<Property name="log-path" value="logs/"/>
<Property name="file-name" value="server"/>
<Property name="file-type" value=".log"/>
</Properties>
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
</Console>
<RollingFile name="File" fileName="${log-path}${file-name}${file-type}"
filePattern="${file-name}-%d{yyyy.MM.dd_HH.mm.ss}-%i.log">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
<SizeBasedTriggeringPolicy size="1 MB"/>
</RollingFile>
</Appenders>
<Loggers>
<Root level="info">
<AppenderRef ref="File"/>
<AppenderRef ref="Console"/>
</Root>
</Loggers>
i have tried to use: <Property name="file-name" value="%logger"/> like in the use in PatternLayout and <Property name="file-name" value="%c{10}"/> witout secssus...

You can't do it like that with the RollingFileAppender. The appender receives log events as configured by your <Loggers> block, if log4j sends it log events with different LoggerNames they will be appended to whatever file is open. A RollingFileAppender writes to one file at a time and rolls when the configured policy tells it to.
You could write to different files by setting up multiple Loggers that target different appenders. Like this:
<Configuration status="info">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
</Console>
<RollingFile name="FileA"
filePattern="/tmp/A-%d{yyyy.MM.dd_HH.mm.ss}-%i.log">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
<SizeBasedTriggeringPolicy size="1 MB"/>
</RollingFile>
<RollingFile name="FileB"
filePattern="/tmp/B-%d{yyyy.MM.dd_HH.mm.ss}-%i.log">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
<SizeBasedTriggeringPolicy size="1 MB"/>
</RollingFile>
</Appenders>
<Loggers>
<Logger name="org.example.App" level="info" additivity="false">
<AppenderRef ref="FileA"/>
</Logger>
<Logger name="org.example.App2" level="info" additivity="false">
<AppenderRef ref="FileB"/>
</Logger>
<Root level="info">
<AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>
To route each event to a different RollingFileAppender based on some pattern you can use a RoutingAppender.
The RoutingAppender evaluates LogEvents and then routes them to a subordinate Appender. The target Appender may be an appender previously configured and may be referenced by its name or the Appender can be dynamically created as needed. The RoutingAppender should be configured after any Appenders it references to allow it to shut down properly.
You can also configure a RoutingAppender with scripts: you can run a script when the appender starts and when a route is chosen for an log event.
Here is how you could route based on LoggerName:
<Configuration status="info">
<Properties>
<Property name="log-path" value="logs/"/>
<Property name="file-name" value="server"/>
<Property name="file-type" value=".log"/>
</Properties>
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
</Console>
<Routing name="Routing">
<Routes pattern="$${event:Logger}">
<Route>
<RollingFile name="Rolling-${event:Logger}" fileName="${log-path}${file-name}-${event:Logger}${file-type}"
filePattern="${file-name}-%d{yyyy.MM.dd_HH.mm.ss}-%i-${event:Logger}.log">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
<SizeBasedTriggeringPolicy size="1 MB"/>
</RollingFile>
</Route>
</Routes>
</Routing>
</Appenders>
<Loggers>
<Root level="info">
<AppenderRef ref="Routing"/>
<AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>
Also, out of interest, if you really want to you can implement your own Appender that does whatever you want with the LogEvent.
Here's a very rough start. It's an Appender that creates a RollingFileAppender per LoggerName. It only works if you use a SizeBasedTriggeringPolicy. You should be able to drop a class like that into your project and use XML like:
<Configuration status="info">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
</Console>
<FilePerLoggerNameAppender name="File"
filePattern="/tmp/log-%d{yyyy.MM.dd_HH.mm.ss}-%i-$LOGGER$.log">
<PatternLayout pattern="%d{dd.MM.yyyy HH:mm:ss.SSS} %-5level %logger - %msg%n"/>
<SizeBasedTriggeringPolicy size="1 MB"/>
</FilePerLoggerNameAppender>
</Appenders>
<Loggers>
<Root level="info">
<AppenderRef ref="File"/>
<AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>
and see log files created with $LOGGER$ replaced with your logger names.

Logging to a file

I'm using the following .xml configuration to log to the console and also to a file.
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Properties>
<Property name="basePath">/logs</Property>
</Properties>
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<RollingFile name="File" fileName="${basePath}/log.log" filePattern="${basePath}/log-%d{yyyy-MM-dd}.log" immediateFlush="true">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
<Policies>
<TimeBasedTriggeringPolicy interval="1" modulate="true" />
</Policies>
</RollingFile>
</Appenders>
<Loggers>
<Root level="error">
<AppenderRef ref="Console"/>
<AppenderRef ref="File"/>
</Root>
</Loggers>
</Configuration>
The problem is when I use the following code I get logs on the console but nothing is written to a file.
private static final Logger logger = LogManager.getLogger(App.class);
logger.error("Start App");
Also sometimes I get the following messages when I debug:
Note: when I print out System.getProperty("log4j.configurationFile") I get null

configure log4j with custom level of verbose

I want to configure my log4j.xml with custom level of verbose - say 350 - in order to print up to some verbose level and including new prints of telemetry that will be at this new level - 350.
What is wrong/missing in my file?
<!--print logs of telemetry, warning and above -->
<CustomLevels>
<CustomLevel name="telemetryLevel" intLevel="350"/>
</CustomLevels>
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<RollingFile name="deviceTelemetry" fileName="/home/device/telemetry-${date:yyyy-MM-dd}.log" append="false"
filepattern="/home/device/telemetry-${date:yyyy-MM-dd}-%i.log">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
<Policies>
<OnStartupTriggeringPolicy />
<SizeBasedTriggeringPolicy size="10M"/>
</Policies>
<DefaultRolloverStrategy max="5"/>
</RollingFile>
</Appenders>
<Loggers>
<Logger name="deviceTelemetry" level="telemetryLevel">
<AppenderRef ref="deviceTelemetry"/>
</Logger>
<Root>
<AppenderRef ref="Console" level="trace"/>
</Root>
</Loggers>
this way i get the logger in code:
Logger log = LogManager.getLogger("deviceTelemetry");
i don't know yet how to call the logger to append a message. there is a method log(Level level, String message) which gets a level so it might work - i cannot check it yet.