Category instances seem to be create only. Why isn there a method to remove category instances?
It is quite nontrivial to define the semantics of a “removed” category which is still referenced by the user. Future releases may include a remove method in the Category class. Is it possible to direct log output to different appenders by priority? Yes it is. Setting the Threshold option of any appender extending AppenderSkeleton, (most log4j appenders extend AppenderSkeleton) to filter out all log events with lower priority than the value of the threshold option. For example, setting the threshold of an appender to DEBUG also allow INFO, WARN, ERROR and FATAL messages to log along with DEBUG messages. (DEBUG is the lowest priority). This is usually acceptable as there is little use for DEBUG messages without the surrounding INFO, WARN, ERROR and FATAL messages. Similarly, setting the threshold of an appender to ERROR will filter out DEBUG, INFO and ERROR messages but not FATAL messages. This policy usually best encapsulates what the user actually wants to do, as opposed to her mind-pr
