Loggers may be assigned levels. The
set of possible levels, that is DEBUG,
INFO, WARN, ERROR and FATAL are
defined in the org.apache.log4j.Level
If a given logger is not assigned
a level, then it inherits one from
its closest ancestor with an assigned
root logger resides at the top of
the logger hierarchy. It always exists
and always has an assigned level.
The logger is the core component of
the logging process. In log4j, there
are 5 normal levels Levels of logger
available (not including custom Levels),
the following is borrowed from the
log4j API (http://jakarta.apache.org/log4j/docs/api/index.html):
static Level DEBUG -
The DEBUG Level designates fine-grained
informational events that are most
useful to debug an application.
static Level INFO - The INFO level designates informational
messages that highlight the progress
of the application at coarse-grained
static Level WARN - The WARN level designates potentially
static Level ERROR - The ERROR level designates error
events that might still allow the
application to continue running.
static Level FATAL - The FATAL level designates very
severe error events that will presumably
lead the application to abort.
In addition, there are two special
levels of logging available: (descriptions
borrowed from the log4j API http://jakarta.apache.org/log4j/docs/api/index.html):
static Level ALL -The
ALL Level has the lowest possible
rank and is intended to turn on all
static Level OFF - The OFF Level has the highest possible
rank and is intended to turn off logging.