org.apache.log4j Class Level

ALL     The ALL has the lowest possible rank and is intended to turn on all logging.

DEBUG   The DEBUG Level designates fine-grained informational events that are most useful to debug an application

ERROR   The ERROR level designates error events that might still allow the application to continue running.

FATAL   The FATAL level designates very severe error events that will presumably lead the application to abort.

INFO    The INFO level designates informational messages that highlight the progress of the application at coarse-grained level

OFF     The OFF has the highest possible rank and is intended to turn off logging.

TRACE   The TRACE Level designates finer-grained informational events than the DEBUG

WARN    The WARN level designates potentially harmful situations.