Why one can't submit an alternative thread pool to the streams API?

[Cay Horstmann]

Il 12/10/19 19:03, Brian Goetz ha scritto:
>> It certainly isn't elegant. Perhaps a better way might be an argument 
>> to the parallel method that specifies the pool to be used?
> 
> This was discussed early during the development of the streams API, and 
> quickly went into the bucket labeled “obvious but wrong.”  (It’s in good 
> company.)  For every case where this is the right move, there are 10,000 
> others where it will be an attractive nuisance, but wrong.  It wouldn’t 
> be fair to Java developers to dangle this option in their face.
> 
> Further, while everyone agrees the real estate between `.parallel(` and 
> `)` is the right place to “build” to provide more control over parallel 
> execution, no one agrees what we should actually build there.  Pretty 
> convinced that a FJP is the wrong thing to build there, but still not 
> sure what the right thing is, so we leave it undeveloped for now.

That is certainly a fair point. I have the same complaint about 
HttpClient.Builder.executor​(Executor executor), which has led 
developers astray.

Cheers,

Cay