ALL | Logs everything -- quite a bit of stuff. |
DEBUG | Logs detailed information that could be useful during debugging. |
ERROR | Logs an error. |
INFO | Logs information. |
NULL | A valid logger that ignores all messages. |
SPAM | Logs extremely verbose and detailed information that is typically useful only to product implementors. |
TRACE | Logs information related to lower-level operation. |
WARN | Logs a warning. |
branch(TreeLogger.Type, String, Throwable) | Produces a branched logger, which can be used to write messages that are logically grouped together underneath the current logger. |
isLoggable(TreeLogger.Type) | Determines whether or not a log entry of the specified type would actually be logged. |
log(TreeLogger.Type, String, Throwable) | Logs a message and/or an exception. |
The log message supplied when branching serves two purposes. First, the
message should be considered a heading for all the child messages below it.
Second, the type
of the message provides a hint as to the
importance of the children below it. As an optimization, an implementation
could return a "no-op" logger if messages of the specified type weren't
being logged, which the implication being that all nested log messages were
no more important than the level of their branch parent.
As an example of how hierarchical logging can be used, a branched logger in a GUI could write log message as child items of a parent node in a tree control. If logging to streams, such as a text console, the branched logger could prefix each entry with a unique string and indent its text so that it could be sorted later to reconstruct a proper hierarchy.
null
if
only an exception is being loggednull
if only a message is being loggednull
arguments for bothmsg
and
caught
, in which case the log event can be ignored.null
if
only an exception is being loggednull
if only a message is being logged