Currently there are 2 public SequenceFile.Reader constructors, 3 public SequenceFile.Writer constructors, 9 public SequenceFile.createWriter, 2 public MapFile.Reader constructors, and 8 public MapFile.Writer constructors. All of with various historical combinations of parameters that don't cover the entire space.
All of this makes it very difficult to add new optional parameters to SequenceFile and MapFile.
I'd like change to the style of FileContext.create with option parameters. I'll implement one public SequenceFile.Reader constructor and one public SequenceFile.createWriter and implement all of the current variants based on those two. I'll do the same for MapFile.Reader and MapFile.Writer including passing parameters down to the underlying SequenceFile.