Disabling Log4J Output in Java - java

How can one quickly turn off all Log4J output using a log4j.properties file?

Set level to OFF
(instead of DEBUG, INFO, ....)

If you want to turn off logging programmatically then use
List<Logger> loggers = Collections.<Logger>list(LogManager.getCurrentLoggers());
loggers.add(LogManager.getRootLogger());
for ( Logger logger : loggers ) {
logger.setLevel(Level.OFF);
}

log4j.rootLogger=OFF

You can change the level to OFF which should get rid of all logging. According to the log4j website, valid levels in order of importance are TRACE, DEBUG, INFO, WARN, ERROR, FATAL. There is one undocumented level called OFF which is a higher level than FATAL, and turns off all logging.
You can also create an extra root logger to log nothing (level OFF), so that you can switch root loggers easily. Here's a post to get you started on that.
You might also want to read the Log4J FAQ, because I think turning off all logging may not help. It will certainly not speed up your app that much, because logging code is executed anyway, up to the point where log4j decides that it doesn't need to log this entry.

In addition, it is also possible to turn logging off programmatically:
Logger.getRootLogger().setLevel(Level.OFF);
Or
Logger.getRootLogger().removeAllAppenders();
Logger.getRootLogger().addAppender(new NullAppender());
These use imports:
import org.apache.log4j.Logger;
import org.apache.log4j.Level;
import org.apache.log4j.NullAppender;

Change level to what you want. (I am using Log4j2, version 2.6.2). This is simplest way, change to <Root level="off">
For example: File log4j2.xml
Development environment
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<Console name="SimpleConsole" target="SYSTEM_OUT">
<PatternLayout pattern="%msg%n"/>
</Console>
</Appenders>
<Loggers>
<Root level="error">
<AppenderRef ref="Console"/>
</Root>
</Loggers>
<Loggers>
<Root level="info">
<AppenderRef ref="SimpleConsole"/>
</Root>
</Loggers>
</Configuration>
Production environment
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<Console name="SimpleConsole" target="SYSTEM_OUT">
<PatternLayout pattern="%msg%n"/>
</Console>
</Appenders>
<Loggers>
<Root level="off">
<AppenderRef ref="Console"/>
</Root>
</Loggers>
<Loggers>
<Root level="off">
<AppenderRef ref="SimpleConsole"/>
</Root>
</Loggers>
</Configuration>

Related

Sentry log4j2 appender cannot add environment

I am using the Sentry log4j appender(version: 5.7.1) to send logged exceptions to Sentry. bellow is the log4j2.xml configuration.
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn" packages="org.apache.logging.log4j.core,io.sentry.log4j2">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<Sentry name="Sentry"
dsn="https://dsn" />
</Appenders>
<Loggers>
<Root level="info">
<AppenderRef ref="Sentry"/>
<AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>
Now I need to add a specific environment in order to differentiate records based on the QA and Production environment. when I add environment="qa", it gives following error.
ERROR Sentry contains an invalid element or attribute "environment"
In Log4j2 integration, properties other than "dsn" can be configured either using:
environment variable: "SENTRY_ENVIRONMENT=qa"
system property "sentry.environment=qa"
sentry.properties file with content: environment=qa
Read more in docs: https://docs.sentry.io/platforms/java/configuration/

Log4j2 Define 2 root loggers with different levels

I have 2 appenders I'm using - Console and custom appender called MyAppender which should ignore all messages with levels lower than ERROR (meaning - it should only support ERROR and FATAL). The Console should be able to support all levels.
I've tried several ways to define it but it seems that the filter doesn't work for the root level appenders. How can this be achieved? My current log4j2 definition:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration packages="com.mysample.logging.appenders" status="DEBUG">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<ThresholdFilter level="DEBUG" onMatch="ACCEPT" onMismatch="DENY"/>
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<MyAppender name="MyAppender">
<ThresholdFilter level="ERROR" onMatch="ACCEPT" onMismatch="DENY"/>
</MyAppender>
</Appenders>
<Loggers>
<Root level="ALL">
<AppenderRef ref="Console"/>
<AppenderRef ref="MyAppender" />
</Root>
</Loggers>
</Configuration>
The loggers are one hierarchy starting with the root logger.
There are no two root loggers within one working setup of Log4j.
What you want to achieve is to have different thresholds on the appenders. Check the link that Piotr suggested:
Using log4j2, is it possible to assign a specific level to a appender?

In Log4j2, Is it possible to filter out certain key value pairs from the logger based on the key?

Can Log4j2 be configured in such a way that the filters or some other components can filter out certain values from getting printed in the log? (but should allow other fields in the same line to pass through)
Say the following lines appear in the log
[operation=DONE, userName=junitUser, tenant=Tenant [tenantID=default], needDetails=1, message=BaseMsg [version=1.0, sdk=AppSDK [version=1.3, protocols=[4aac81ca, 393ae7a0]], device=Device [id=12345, type=Pompom, info=Dot's Device]]], channel=null
[operation=DONE, userName=junitUser224, tenant=Tenant [tenantID=default], needDetails=1, message=BaseMsg [version=1.0, sdk=AppSDK [version=1.3, protocols=[4aac81ca,393ae7a0]], device=Device [id=123456, type=Mamamia, info=tom's Device]]], channel=null
Now can I filter out the "userName" field in such a way that the log lines now do not contain it as shown below?
[operation=DONE, tenant=Tenant [tenantID=default], needDetails=1, message=BaseMsg [version=1.0, sdk=AppSDK [version=1.3, protocols=[4aac81ca, 393ae7a0]], device=Device [id=12345, type=Pompom, info=Dot's Device]]], channel=null
[operation=DONE, tenant=Tenant [tenantID=default], needDetails=1, message=BaseMsg [version=1.0, sdk=AppSDK [version=1.3, protocols=[4aac81ca,393ae7a0]], device=Device [id=123456, type=Mamamia, info=tom's Device]]], channel=null
Here is my log4j2.xml
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
<RollingFile name="RollingFile" fileName="/Users/dunston/logs/app.log"
filePattern="logs/app-%d{MM-dd-yyyy}.log.gz">
<RegexFilter regex=".* zinger_log .*" onMatch="ACCEPT" onMismatch="DENY"/>
<PatternLayout>
<pattern>%d %p %c{1.} [%t] %m%n</pattern>
</PatternLayout>
<TimeBasedTriggeringPolicy />
</RollingFile>
</Appenders>
<Loggers>
<Root level="debug">
<AppenderRef ref="Console"/>
<AppenderRef ref="RollingFile"/>
</Root>
</Loggers>
</Configuration>
This can be accomplished with a RewriteAppender.
You may need to write a custom RewritePolicy that inspects the LogEvent's Message and replaces the Message with another instance if the formatted message contains a regular expression that you want to filter out.
Your custom RewitePolicy can be configured in the configuration like any other standard Log4j2 plugin.

print format in apache commons logging

Using log4j underneath.
How can I do, format or wildcard stuff like:
System.out.printf('%s', 5)
With
log.info('%s', 5) //org.apache.commons.logging.Log instance
Version:commons-logging-1.1.3.jar.
The bad thingy about this mentioned API is:
It has methods info(object) and info(object, throwable) only.
Or logging did not evolve there??
This is probably the easiest way to do it
log.info(String.format("%s", 5));
The feature you are looking for is included in log4j2:
http://www.apache.org/dyn/closer.cgi/logging/log4j/2.1/apache-log4j-2.1-bin.zip
You have to include at least two jar files:
log4j-api-2.1.jar
log4j-core-2.1.jar
Finally put a configuration file named "log4j2.xml" in your classpath which can look like this:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
<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="info">
<AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>
After the configuration you should be able to achieve what you want with the following code:
Logger log = LogManager.getLogger(YOURCLASSNAME.class);
log.printf(Level.INFO,"%s",5);
Yes, it is achievable in "slf4j". Try using the below snapshots-
log.info("My name is %s %s",firstName,secondName)
or
LOG.debug("WidgetName:{}\n curWidgetVOArray=\n",curWidgetName, curWidgetVOArray);
Refer - http://javarevisited.blogspot.in/2013/08/why-use-sl4j-over-log4j-for-logging-in.html

log4j2.xml is not loading in eclipse

I'm fairly new to log4j. Trying to use log4j2.xml to configure. I added the file to the build path and it worked once, but is no longer working.
This is my log4j2.xml:
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<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="TRACE">
<appender-ref ref="Console"/>
</root>
</loggers>
</configuration>
I stripped it down, just to test it to get it working. I checked debug, and the logger config is using Default.
I also tried naming the file log4j2-test.xml.
Any ideas?
Thanks
Since you uses "servlets" as the tag, I assume you are working in a web application. You need to place your log4j.xml into a location that your web application classloader can find. For example, the WEB-INF/classes directory.

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