General steps for using log4j

It is hard to remember, so some of the Notes should be recorded.

1. Create a log4j. properties configuration file and place it in the same path of the main portal class.

Og4j. rootlogger = debug, stdout, R

Log4j. appender. stdout = org. Apache. log4j. leleappender
Log4j. appender. stdout. layout = org. Apache. log4j. patternlayout

# Pattern to output the caller's file name and line number.
Log4j. appender. stdout. layout. conversionpattern = % d % 5 p [% T] (% F: % L)-% m % N

Log4j. appender. r = org. Apache. log4j. rollingfileappender
Log4j. appender. R. File = yesftp. Log

Log4j. appender. R. maxfilesize = 1000kb
# Keep one backup file
Log4j. appender. R. maxbackupindex = 1

Log4j. appender. R. layout = org. Apache. log4j. patternlayout
Log4j. appender. R. layout. conversionpattern = % d % 5 p [% T] (% F: % L)-% m % N

 

2. initialize log4j in the static area of the entry class

Static {
Propertyconfigurator. Configure (
Yesftpclientframe. Class. getresource ("log4j. properties "));
}

 

3. initialize a private static variable in every location where logs are needed.

Private Static logger = logger. getlogger (XX. Class );

 

4. Use the methods provided by log4j

Logger.info ("hello ");

5. Use log4j to output abnormal stack information

Logger. Error ("Oops, got an exception:", e );