Log4j Quick Reference Card Priorities Level ALL TRACE DEBUG INFO WARN ERROR FATAL OFF
Description Output of all messages Detailed Debugging Debugging (Method xy called with param abc …) General information (Program started/ended, connected to host foo, calculation took n seconds) Unexpected situation Error (Exception caught) Critical error, program stops Logging is deactivated
Usage: log4j.rootLogger=Level, Appender, Appender, ... log4j.logger.Package.Package.Class=Level
Appenders Name ConsoleAppender FileAppender RollingFileAppender DailyRollingFileAppender SyslogAppender NTEventLogAppender SMTPAppender net.SocketAppender net.SocketHubAppender
Writes to Stdandard Output (Console) File File, creates a new based on file size File, creates a new based on time UNIX Syslog Windows Event-Log e-mail Socket (client mode) Socket (server mode)
Usage: log4j.appender.Appender=org.apache.log4j.Name
Layouts Name PatternLayout SimpleLayout TTCCLayout HTMLLayout XMLLayout
Description Conversion Pattern Level and Message = time, thread, category, context HTML Table XML
Usage: log4j.appender.Appender.layout=org.apache.log4j.Name
PatternLayout c category; a.b.c -> %c{2} = a.b C fully qualified class name (slow); org.apache.xyz.SomeClass -> %C{1} = SomeClass d date; %d{HH:mm:ss,SSS}, %d{ABSOLUTE}, %d{DATE}, %d{ISO8601} F file name (extremly slow) l location (extremly slow) L line number (extremly slow) % percent sign
m message M method name (extremly slow) n line separator; \n or \r\n p priority r milliseconds from layout construction t thread name x nested diagnostic context of thread X mapped diagnositc context of thred; %X{clientNumber}
Format Modifier Modifier %20c %-20c %.30c %20.30c
left justify false true NA false
%-20.30c true
min. width 20 20 none 20
max. width none none 30 30
20
30
comment Left pad with spaces if the name is less than 20 characters long. Right pad with spaces if the name is less than 20 characters long. Truncate from the beginning if the name is longer than 30 characters. Left pad with spaces if the name is shorter than 20 characters. However, if category name is longer than 30 characters, then truncate from the beginning. Right pad with spaces if the name is shorter than 20 characters. However, if category name is longer than 30 characters, then truncate from the beginning.
log4j.rootLogger=WARN, stdout, logfile, socket log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%-5p [%-4t] %-25.25c %m%n log4j.appender.logfile=org.apache.log4j.RollingFileAppender log4j.appender.logfile.File=${java.io.tmpdir}/myapp.log log4j.appender.logfile.MaxFileSize=512KB log4j.appender.logfile.MaxBackupIndex=3 log4j.appender.logfile.layout=org.apache.log4j.PatternLayout log4j.appender.logfile.layout.ConversionPattern=%d %r [%t] %-5p %c %x - %m%n log4j.appender.socket=org.apache.log4j.net.SocketHubAppender log4j.appender.socket.port=10005 log4j.appender.socket.locationInfo=true log4j.logger.com.my.app=DEBUG