Many API share a common approach of Reader and Writer.
This interface and the AbstractReader provides the general needs
to open, convert to binary or char stream and dispose them.
author  Johann Sorel

Set the reader input.
The type of input supported may change based on the reader.
param  input source to read from,
throws  IOException if input type is not supported.

Get the currently set input.
return  Object can be null.

Release this reader, freeing any additional resources opened
by the reader.
Implementation may be reusable other not.
throws  IOException if freeing all resources failed.