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How to separate web application logging in Tomcat

I have my webapp some-app.war running under Tomcat 8.5. I use Slf4j and Logback for logging within the webapp. When I log using log.info() or similar, the output gets written to catalina.out, the same log file as Tomcat uses for its internal logging. I want the logs from my application to be written to a separate log file. But I do NOT want to use logback's FileAppender to do it. I'd prefer to leave Logback using ConsoleAppender as I may deliver the WAR to others who won't have the same logging needs. I see the location of the log file as an aspect of the deployment environment, not the code.
Is there a way that I can manage per-application log files from the configuration of the Tomcat server itself -- while still using Slf4j and Logback in my code?

You can't know about others' logging needs, so there's not a silver bullet solution for this. However I'm sure the best option is not "I'm gonna leave it configured really badly because someone might log differently".
You can configure it how you wish for yourself, using FileAppenders and document the necessary steps to reconfigure it (e.g. edit the war).
You can also use more advanced configurations such as making use of syslog. Now other users have a standardized configuration option, just as long as they use syslog.
There are other options as well, but the common thread here is that you can't know what others may want, so don't waste time trying to guess it. Just do what works well for you at least.

If you placed logging.properties at [CATALINA_HOME/conf/logging.properties] then it should use it as your root logging properties file. Put you logging.properties or log.xml file in your application at [MyApp/WEB_INF/classes/logging.properties] and configure it like blow.
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration debug="true"
xmlns:log4j='http://jakarta.apache.org/log4j/'>
<appender name="stderr" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="Target" value="System.err"/>
<param name="ConversionPattern"
value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
</layout>
</appender>
<appender name="stdout" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="Target" value="System.out"/>
<param name="ConversionPattern"
value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
</layout>
</appender>
<appender name="file" class="org.apache.log4j.RollingFileAppender">
<param name="append" value="true" />
<param name="maxFileSize" value="2MB" />
<param name="maxBackupIndex" value="100" />
<param name="file" value="${catalina.base}/logs/MyApp/MyApp.log" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern"
value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
</layout>
</appender>
<root>
<level value="DEBUG" />
<appender-ref ref="stdout" />
<appender-ref ref="stderr" />
<appender-ref ref="file" />
</root>
</log4j:configuration>

log4j.xml configuration for debugging only

I am new to log4j and was just wondering if someone could help me with a configuration that I am currently guessing. I'm trying to test it but it doesn't seem to be working.
<?xml version="1.0" encoding="UTF-8" ?>
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="false">
<appender name="debugAppender" class="org.apache.log4j.RollingFileAppender">
<param name="File" value="/usr/local/apache-tomcat-7.0.35/logs/sample.log"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %-5p [%c{1}] %m %n" />
</layout>
<filter class="org.apache.log4j.varia.LevelRangeFilter">
<param name="levelMax" value="DEBUG" />
</filter>
</appender>
<logger name="com.webservice" additivity="false">
<priority value="DEBUG" />
<appender-ref ref="debugAppender" />
</logger>
<root>
<priority value="ERROR" />
<appender-ref ref="fileAppender" />
</root>
</log4j:configuration>
What I am trying to do here is set the root logger to ERROR so that it does not pick up anything unless there is an error. But then I have a logger named com.webservice that I would like to have pick up DEBUG statements from my packages(and not other libraries) only for development purposes.
When I go to production I want to change the com.webservice priority back to INFO so that it does not pick up any logging.
Have I set this file up correctly?
thanks

Try to set debug attribut in log4j:configuration node to true.
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="true">
It prints out information as the configuration file is read and used to configure the log4j environment. You may be got more details to resolve your problem.

I havent worked on xml but I use log4j.properties which works perfectly fine. Just place this in your classpath and add jar for log4j. It should work. You can change log levels as you want.
Also there is no need to specify ERROR level as by default ERROR level gets logged.
Sample :
log4j.debug=TRUE
log4j.logger.com.XXX.RemoteCacheManager=FATAL, Logs
log4j.logger.com.XXX.RedisCacheImpl=FATAL, Logs
log4j.logger.com.XXX.utils=DEBUG, TimeItLogs
log4j.logger.com.XXX=DEBUG, Logs
log4j.logger.org.hibernate=INFO, Logs
log4j.logger.org.springframework=INFO, Logs
log4j.logger.org.apache.velocity=ERROR, Logs
log4j.logger.org.apache.commons=ERROR, Logs
log4j.logger.org.apache.tiles=ERROR, Logs
log4j.appender.Logs=org.apache.log4j.RollingFileAppender
log4j.appender.Logs.File=${catalina.base}/logs/XXX.log
log4j.appender.Logs.MaxFileSize=10MB
log4j.appender.Logs.MaxBackupIndex=50
log4j.appender.Logs.layout=org.apache.log4j.PatternLayout
log4j.appender.Logs.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %p %t %c %m %n

Possible to use different log4j appenders for different methods?

I have a log4j configuration file and it uses a ConsoleAppender with a specific layout.
I use
logger.info("some text");
in several places in my java code.
Is it possible to create another appender with a different layout in the configuration file and use the specific appender wherever I choose in the code?

Is it possible to create another appender with a different layout in the configuration file and use the specific appender wherever I choose in the code?
Yes you can create different appender with a different layout and create different categories for each appender.
use the category name to get the logger instead of appender name.
Sample: (log4j.xml)
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="stdout1" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="[%.4t] %-5p %c{1} - %m%n" />
</layout>
</appender>
<appender name="stdout2" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d [%.4t] %-5p %c{1} - %m%n" />
</layout>
</appender>
<category name="category1">
<priority value="INFO" />
<appender-ref ref="stdout1" />
</category>
<category name="category2">
<priority value="DEBUG" />
<appender-ref ref="stdout2" />
</category>
</log4j:configuration>
Java Code: (get the logger based on category name)
org.apache.log4j.Logger.getLogger("category1").warn("debug msg for stdout1 appender");
org.apache.log4j.Logger.getLogger("category2").info("info msg for stdout2 appender");
Output:
[main] WARN category1 - warn msg for stdout1 appender
2014-05-09 02:46:29,216 [main] INFO category2 - info msg for stdout2 appender

How to set value in log4j.xml using property file?

I would like to know if there is possibility to set an attribute in log4j.xml by using property file. For example the log4j.xml:
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration>
<appender name="CONSOLE" class="org.apache.log4j.ConsoleAppender">
<param name="target" value="System.out" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{ISO8601} %-5p [%c{1}] - %l - %m%n "/>
</layout>
</appender>
<appender name="FILE" class="org.apache.log4j.FileAppender">
<param name="File" value="\D:\ReadText_File\log4jlogss.txt"/>
<param name="Append" value="true"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d{ISO8601} %-5p [%c{1}]- %l - %m%n"/>
</layout>
</appender>
<logger name="org.apache">
<level value="WARN"/>
</logger>
<root>
<level value="DEBUG"/>
<appender-ref ref="FILE"/>
<appender-ref ref="CONSOLE"/>
</root>
</log4j:configuration>
I wan to specify the path for the file using Properties file
Any idea how can we do it ????

about log4j, this type of configuration that XML configuration which embed the property file is not supported in current version.
for details, you can view the log4j's source code . the XML parse details is in class
DOMConfigurator.configure

You can use Log4j Lookups with PropertySubstitution:
See http://logging.apache.org/log4j/2.x/manual/configuration.html#PropertySubstitution and http://logging.apache.org/log4j/2.x/manual/lookups.html
Here is an example on StackOverflow: Log4J2 property substitution - default
(to make it short, you can use, as far as I know, the System Property using -Dkey=value)
You can also try to use the ${bundle:com.package.Messages:MyKey} syntax to use a properties file (using log4j 2.0-rc1 or greater), see https://stackoverflow.com/a/19303208/1149528.

How to get java Logger output to file by default [duplicate]

This question already has answers here:
Where does java.util.logging.Logger store their log
(3 answers)
Closed 9 years ago.
Netbeans thoughtfully sprinkles Logger.getLogger(this.getClass().getName()).log(Level. [...]
statements into catch blocks. Now I would like to point them all to a file (and to console).
Every logging tutorial and such only me tells how to get a specific logger to output into a file, but I assume there is a better way than fixing every automatically generated logging statement? Setting a handler for some sort of root logger or something?

I just add the following at startup
Handler handler = new FileHandler("test.log", LOG_SIZE, LOG_ROTATION_COUNT);
Logger.getLogger("").addHandler(handler);
You can specify your own values for LOG_SIZE and LOG_ROTATION_COUNT
You may need adjust the logging level to suit.

You have to define where the log is writting in the logger configuration file.
For example, if you use log4j, a log4j.xml (or log4j.properties) file will contain such information.
For example, here is a simple log4j.xml file that logs directly into a file (my-app.log) and in the console:
<?xml version="1.0" encoding="UTF-8"?>
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="rolling" class="org.apache.log4j.DailyRollingFileAppender">
<param name="File" value="my-app.log" />
<param name="DatePattern" value=".yyyy-MM-dd" />
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern"
value="%d{yyyy-MM-dd HH:mm:ss} %-5p [%C] [IP=%X{ipAddress}] [user=%X{user}] %m%n" />
</layout>
</appender>
<appender name="console" class="org.apache.log4j.ConsoleAppender">
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern"
value="%d{yyyy-MM-dd HH:mm:ss} %-5p [%C] [user=%X{user}] %m%n" />
</layout>
</appender>
<root>
<priority value="info" />
<appender-ref ref="console" />
<appender-ref ref="rolling" />
</root>
</log4j:configuration>