JEPs proposed to target JDK 9

[Alan Bateman]

On 05/11/2014 19:36, Ben Evans wrote:
> :
>
> Modularity, on the other hand, as currently envisaged, is going to
> break vast numbers (if not virtually every) tool in the ecosystem, and
> require fundamental changes to a lot of tools.

Just on this, the goal is not to break anything using Java SE or 
supported JDK APIs. There will be a small number of exceptions of 
course, some flagged for a long time, but I hope not too many.

We know that a lot of tools have to go off-piste and directly access 
rt.jar and other files in the JDK image themselves. I think we have 
reasonable proposal in JEP 220 and once the tool makers are engaged and 
working with JDK 9 builds then this part might not be too bad. There are 
already EA builds with most of what is in JEP 220 and there is outreach 
underway to create awareness, get some early testing, and I hope get 
some data or feedback on impact too. If we can get the changes into JDK 
9 early then it would help too.

Clearly once we have a module system in place then upgrading the tools 
and the eco system to support modules will be a huge effort and it's not 
going to happen overnight. You've listed many important points, even 
your point about being receptive to course corrections if some aspects 
turn out to be major pain points. Clearly we will are going to need a 
lot of support from everywhere to get through some of the transitions 
that are envisaged. Tools aside then I think the biggest transition is 
going to be weaning code off of direct use of JDK-internal APIs, that is 
also not going to happen overnight.


>
> I've broadened this thread out to include the JCP EC as I feel that
> the changes that have been proposed as part of JEP 220
> (http://openjdk.java.net/jeps/220) need to be on their radar at this
> early stage.

One thing to say about JEP 220 is that most of it is implementation 
related (very few "spec" changes).

-Alan.