How to print stack trace in log file

Question

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

You can view bellow thread. It has complete answer https://stackoverflow.com/a/51655824/3073945 — Md. Sajedul Karim, Aug 02 '18 at 14:18

score 45 · Accepted Answer · answered Apr 06 '12 at 08:11

45

You have to write

logger.error("Error description",ex);

Look at the javadoc, the exception must be the second arguments if you want stacktrace.

answered Apr 06 '12 at 08:11

dash1e

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What if it's not an exception, you're using `logger.error` for a custom error message and you want to print the stacktrace anyways? – Mark Apr 16 '14 at 22:31

score 9 · Answer 2 · answered Apr 06 '12 at 08:11

9

Typically, you can pass the Throwable instance to the logger as well, e.g.

logger.error( "My custom message", exception )

answered Apr 06 '12 at 08:11

Robin

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How to print stack trace in log file

2 Answers2