Registers a listener for changes in the specified attributes. If listener is
null
, no exception is thrown and no action is performed. To determine the attribute updates that may be reported by this job, a client can call
getAttributes()
and identify the subset that are interesting and likely to be reported to the listener. Clients expecting to be updated about changes in a specific job attribute should verify it is in that set, but updates about an attribute will be made only if it changes and this is detected by the job. Also updates may be subject to batching by the job. To minimize overhead in print job processing it is recommended to listen on only that subset of attributes which are likely to change. If the specified set is empty no attribute updates will be reported to the listener. If the attribute set is
null
, then this means to listen on all dynamic attributes that the job supports. This may result in no update notifications if a job can not report any attribute updates.
If listener is already registered, it will be registered again.