Log4j filter by package - log4j

Question

I would like to have log4j (v1.2.17) send ...
... to fileAppender
INFO (and above) from all packages
... to console
if from "my.project" then INFO (and above)
else WARN (and above) for all other packages
How can I do this? I'd prefer a properties file if possible, but would switch to XML if necessary.
I've tried combinations of loggers, non-additivity, Threshold, & LevelMatchFilter but can't figure it out.

Answer 1

This can definitely be done. Below you will find some example code and log4j properties that will do what you want.
Here is the first example class:
package my;
import org.apache.log4j.Logger;
public class Example1 {
private static final Logger logger = Logger.getLogger(Example1.class);
public static void main(String[] args){
logger.debug("debug from my.Example1 - should display nowhere!");
logger.info("info from my.Example1 - should display in log file only!");
logger.warn("warning from my.Example1 - should display in console and log file!");
logger.error("error from my.Example1 - should display in console and log file!");
logger.fatal("fatal from my.Example1 - should display in console and log file!");
}
}
Here is the second example class:
package my.project;
import org.apache.log4j.Logger;
public class Example2 {
private static final Logger logger = Logger.getLogger(Example2.class);
public static void main(String[] args){
logger.debug("debug from my.project.Example2 - should display nowhere!");
logger.info("info from my.project.Example2 - should display in console and log file!");
logger.warn("warning from my.project.Example2 - should display in console and log file!");
logger.error("error from my.project.Example2 - should display in console and log file!");
logger.fatal("fatal from my.project.Example2 - should display in console and log file!");
}
}
Here is the log4j.properties file:
# The root logger will accept INFO messages or higher and send them to the log file
# and to a console appender that filters out any messages below WARN level
log4j.rootLogger=INFO, R, warnStdout
# Configure a console appender that will be used for messages of any level
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
# Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n
#This will be used to print WARN level or higher messages to console
log4j.appender.warnStdout=org.apache.log4j.ConsoleAppender
log4j.appender.warnStdout.layout=org.apache.log4j.PatternLayout
log4j.appender.warnStdout.Threshold=WARN
# Pattern to output the caller's file name and line number.
log4j.appender.warnStdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=test.log
log4j.appender.R.MaxFileSize=100KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n
# Classes in the my.project package will accept messages of INFO level or higher
# and send those messages to the console and to the log file
log4j.logger.my.project=INFO, stdout, R
# Need to set additivity to false or else both the my.project and root loggers
# will accept messages from classes in package my.project
log4j.additivity.my.project=false
Here is the console output after running Example1 followed immediately by Example2:
WARN [main] (Example1.java:11) - warning from my.Example1 - should display in console and log file!
ERROR [main] (Example1.java:12) - error from my.Example1 - should display in console and log file!
FATAL [main] (Example1.java:13) - fatal from my.Example1 - should display in console and log file!
INFO [main] (Example2.java:11) - info from my.project.Example2 - should display in console and log file!
WARN [main] (Example2.java:12) - warning from my.project.Example2 - should display in console and log file!
ERROR [main] (Example2.java:13) - error from my.project.Example2 - should display in console and log file!
FATAL [main] (Example2.java:14) - fatal from my.project.Example2 - should display in console and log file!
Here is the test.log file content after running Example1 followed by Example2:
INFO main my.Example1 - info from my.Example1 - should display in log file only!
WARN main my.Example1 - warning from my.Example1 - should display in console and log file!
ERROR main my.Example1 - error from my.Example1 - should display in console and log file!
FATAL main my.Example1 - fatal from my.Example1 - should display in console and log file!
INFO main my.project.Example2 - info from my.project.Example2 - should display in console and log file!
WARN main my.project.Example2 - warning from my.project.Example2 - should display in console and log file!
ERROR main my.project.Example2 - error from my.project.Example2 - should display in console and log file!
FATAL main my.project.Example2 - fatal from my.project.Example2 - should display in console and log file!