8228392: java.io.Filter{In,Out}put stream constructors should allow null stream parameter

[Alan Bateman]

On 19/07/2019 15:58, Brian Burkhalter wrote:
>
> Given the compatibility issues it might be best to modify the 
> specifications of the Filter*Stream subclass constructors to allow a 
> null underlying stream parameter, thereby overriding the package level 
> javadoc. IOTW align the spec with longstanding behavior.
>
I think it will need a detailed examination to see how each one behaves 
when the input stream is null. As the field is protected it means that 
sub-classes can change its value at any time, maybe because they want to 
set it lazily or maybe they want to set it to null when the stream is 
closed. For classes such as DIS/DOS then it probably means NPE in many 
operations when the stream is null. Other classes (suchas BIS and BOS) 
will interpret it as the closed stream. So it will need a detailed 
analysis but more than likely you will not be able to change long 
standing behavior because it will break existing code.

-Alan