Nir,
The level of interest could be interesting. I do note that there is
more of a trend in
Java API design these days to use factory methods, e.g. the ".of(...)"
pattern so that
would lend weight to such a feature.
That being said, it would then come down to the level of design and
implementation
work required to effect such a change, and whether the cost is worth the
benefit.
There would no doubt be a bikeshed discussion on where such an
annotation might go,
or whether to just use a documentation tag within the comment. The best
precedent
would be @FunctionalInterface, but that is in java.lang, and there is
quite a high bar
to adding types to that package. Then we would have to look at changing the
organization of the page, to move selected methods up into the
Constructors table,
and possibly renaming it to "Constructors and Factory Methods" or
something like that.
A simpler variation would be just another tab in the method table for
"Factory Methods",
perhaps automatically determining static methods that return the
enclosing type. It
would be interesting to see how many false-positives that would catch
(i.e. without even
using an annotation.)
-- Jon
On 10/02/2018 11:49 PM, Nir Lisker wrote:
Hi Jon,
Thanks for the info.
If I bring it up on the Java subreddit and see what people say, would
it count as a measure for interest? How is "sufficient interest"
evaluated, more or less?
- Nir
On Wed, Oct 3, 2018 at 2:27 AM Jonathan Gibbons
<[email protected] <mailto:[email protected]>> wrote:
On 10/02/2018 06:54 AM, Nir Lisker wrote:
Hi,
Many static methods are used to obtain an instance of a class,
functioning as a de-facto constructor and sometimes replacing it
altogether. These are factory or builder methods and the like.
The problem is that while they function as constructors, they are
hidden between the rest of the methods in the JavaDoc. It is my
understanding that the Constructors section shows how to create
an instance, while the Methods section shows how to use it. In
this case, the aforementioned methods will fit better in the
Constructors section.
One way this can be solved is via an annotation on the method
that would list it under the Constructors, used at the developers
discretion. As an example, Toolkit is a singleton:
public class Toolkit {
private final Toolkit TOOLKIT;
private Toolkit() { ... }
@Constructor
public static getDefaultSystemToolkit() { return TOOLKIT; }
}
The annotation shows the intended way for a developer to obtain
the instance.
I can submit an RFE if this is plausible. Otherwise, I'm open for
other solutions if you agree with the problem I presented.
- Nir
Nir,
It's not an unreasonable request, and has been suggested before,
dating back to 2002.
That being said, there has not been sufficient interest to make it
happen.
See this JBS issue for one of the early requests:
https://bugs.openjdk.java.net/browse/JDK-4619333
-- Jon
