How to print stack trace in log file
java, log4j
Solution
You have to write
logger.error("Error description",ex);
Look at the javadoc, the exception must be the second arguments if you want stacktrace.
Problem
I am loging error im my java swing application: `logger.error("ERROR: " + ex);` where ex is exception this just print me `13:33:58,964 ERROR PlayOffPanel:292 - ERROR: java.lang.NullPointerException` but I wanna know stacktrace. my log4j properites: ``` log4j.rootLogger=DEBUG,file log4j.appender.file=org.apache.log4j.RollingFileAppender log4j.appender.file.maxFileSize=100KB log4j.appender.file.maxBackupIndex=5 log4j.appender.file.File=error.log log4j.appender.file.threshold=DEBUG log4j.appender.file.layout=org.apache.log4j.PatternLayout log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n ```