RFR: 8343239: Javadoc marks non-preview type as preview if it's the subtype of a preview type

[Chen Liang]

On Thu, 14 Nov 2024 23:40:37 GMT, Nizar Benalla <nbenalla at openjdk.org> wrote:

> Please review this patch to improve the javadoc preview header. The parent bug include more details.
> 
> This is meant to prevent a bug where, if a non preview class extend an `@PreviewFeature` interface, the Javadoc displays `Programs can only use <<Type>> when preview features are enabled` when the API can be used without enable preview features as long as we don't refer to any methods in the supertype
> 
> This is specifically the case in  #17543. Here is the javadoc output [AsymmetricKey](https://cr.openjdk.org/~nbenalla/GeneratedDocs/8343239-2/docs/api/java.base/java/security/AsymmetricKey.html) after merging this branch with the PR `298420: PEM API: Implementation (Preview) #17543`. The only files affected by this change are the class `DEREncodable` and it's Subinterfaces.
> 
> One other bug I noticed is that, on the `DEREncodable` page, it's direct subinterfaces had the superscript `PREVIEW` link. I've added a condition to remove it.

src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/resources/standard.properties line 443:

> 441: to permanent features of the Java Platform.<br>
> 442: doclet.NonPreviewPreview=Programs can use {0} without enabling preview features. \
> 443:     Programs can only reference the preview API by name when preview features are enabled.

> Programs can only reference the preview API by name when preview features are enabled.

Should we reword like `Programs can only use {0} as {1} when preview features are enabled.` where `{1}` is (the list of) preview feature class(es) or interface(s) this existing class or interface extends/implements.

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PR Review Comment: https://git.openjdk.org/jdk/pull/22126#discussion_r1843055291