Some Classes with a public void close() don't implement AutoCloseable

[Alan Bateman]

On 22/04/2020 13:50, Andrew Haley wrote:
> :
> 1. Should close() always be idempotent, where practical? I would have
>     thought so, but perhaps there are downsides.
>
> 2. Should classes which implement close() with the standard meaning be
>     AutoCloseable?
>
I'm sure Joe Darcy can say more on this but I remember there was a lot 
of effort put into this topic when AutoCloseable was added in Java 7 
(and Project Coin). Closeable close is idempotent but AutoCloseable 
close could not require it. AutoCloseable's API docs recommend it of 
course. There was effort in Java 7 and beyond to retrofit existing 
classes that defined a close method to be Closeable or AutoCloseable. 
There are only a handful of exported APIs remaining that have a close 
method that don't extend or implement AutoCloseable. I don't know the 
history of the XML stream interface to know why they close to define 
them not to close the underlying stream but I doubt these could be 
changed now.

-Alan.