This formater formats the LogEvents according to a input pattern string.

The format of each pattern element can be %[+|-][#[.#]]{field:subformat}.

• The +|- indicates left or right justify.

• The #.# indicates the minimum and maximum size of output. You may omit the values and the field will be formatted without size restriction.
  You may specify #, or #. to only define the minimum size.
  You may specify .# to only define the maximum size.

• field indicates which field is to be output and must be one of properties of LogEvent. The following fields are currently supported:

  category	Category value of the logging event.
  context	Context value of the logging event.
  message	Message value of the logging event.
  time	Time value of the logging event.
  rtime	Relative time value of the logging event.
  throwable	Throwable value of the logging event.
  priority	Priority value of the logging event.
  thread	Name of the thread which logged the event.

• subformat indicates a particular subformat to use on the specified field, and is currently only supported by:

  context	Specifies the context map parameter name.
  time	Specifies the pattern to be pass to SimpleDateFormat to format the time.

A simple example of a typical PatternFormatter format would be:

  %{time} %5.5{priority}[%-10.10{category}]: %{message}

This would produce a line like:

  1000928827905 DEBUG [     junit]: Sample message

The format string specifies that the logger should first print the time value of the log event without size restriction, then the priority of the log event with a minimum and maximum size of 5, then the category of the log event right justified with a minimum and maximum size of 10, followed by the message of the log event without any size restriction.