Question

What is the difference between %u & %g (Log File Pattern Variables) in Java Logging API and when they are used?

Thanks

Answer 1

Found the solution from FileHandler API

If no “%g” field has been specified and the file count is greater than
one, then the generation number will be added to the end of the
generated filename, after a dot.

Thus for example a pattern of “%t/java%g.log” with a count of 2 would
typically cause log files to be written on Solaris to
/var/tmp/java0.log and /var/tmp/java1.log whereas on Windows 95 they
would be typically written to to C:\TEMP\java0.log and
C:\TEMP\java1.log

Generation numbers follow the sequence 0, 1, 2, etc.

while %u make the file name unique if multiple apps trying to log to the same app.