问题
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?
回答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.
回答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
回答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.
回答4:
You can find those logs also in cat /var/log/messages
if you try
cat /var/log/messages | grep server
回答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.
回答6:
In my case (Fedora 29 apache-tomcat-8.5.39), it was found inside catalina.out file located inside logs folder.
来源：https://stackoverflow.com/questions/14158131/where-does-system-out-println-in-tomcat-under-windows-gets-written