Where does system.out.println in tomcat under windows gets written?

Question

I am using a third party library (cannot modify it) that uses for logging system.out.println statements. The output shows fine in the console but I am not able to retrieve those information in the catalina[...].log file?

Is it possible to send those to log4j?

Answer 1

System.out.println() prints out to stdout. Therefore, if you want to see these statements in a log file, you can just redirect stdout where you want it in the Tomcat startup script.

Answer 2

When running Tomcat on unixes, the console output is usually redirected to the file named catalina.out. The name is configurable using an environment variable. (See the startup scripts).

http://tomcat.apache.org/tomcat-7.0-doc/logging.html#Console

Answer 3

If you are running a JSP then you need to add

 <%@ page isThreadSafe="false"  %>

Then all of your System.out.printlns will start showing up in the catalina.out file.

If you start tomcat with Catalina.sh run from a command line you will see the prints in the output.

Answer 4

You can find those logs also in cat /var/log/messages

if you try

cat /var/log/messages | grep server

Answer 5

You can find it inside TOMCAT_HOME/logs/stdout_20130104.txt (the file name may change but the log files are usually in the folder TOMCAT_HOME/logs/.

And for me all the sysouts that I have in my code are written in such a file.

Answer 6

In my case (Fedora 29 apache-tomcat-8.5.39), it was found inside catalina.out file located inside logs folder.