RFR: 8296546: Add @spec tags to API [v3]

[Joe Wang]

On Wed, 23 Nov 2022 18:57:03 GMT, Jonathan Gibbons <jjg at openjdk.org> wrote:

>> Please review a "somewhat automated" change to insert `@spec` tags into doc comments, as appropriate, to leverage the recent new javadoc feature to generate a new page listing the references to all external specifications listed in the `@spec` tags.
>> 
>> "Somewhat automated" means that I wrote and used a temporary utility to scan doc comments looking for HTML links to selected sites, such as `ietf.org`, `unicode.org`, `w3.org`. These links may be in the main description of a doc comment, or in `@see` tags. For each link, the URL is examined, and "normalized", and inserted into the doc comment with a new `@spec` tag, giving the link and tile for the spec.
>> 
>> "Normalized" means...
>> * Use `https:` where possible (includes pretty much all cases)
>> * Use a single consistent host name for all URLs coming from the same spec site (i.e. don't use different aliases for the same site)
>> * Point to the root page of a multi-page spec
>> * Use a consistent form of the spec, preferring HTML over plain text where both are available (this mostly applies to IETF specs)
>> 
>> In addition, a "standard" title is determined for all specs,  determined either from the content of the (main) spec page or from site index pages.
>> 
>> The net effect is (or should be) that **all** the changes are to just **add** new `@spec` tags, based on the links found in each doc comment. There should be no other changes to the doc comments, or to the implementation of any classes and interfaces.
>> 
>> That being said, the utility I wrote does have additional abilities, to update the links that it finds (e.g. changing to use `https:` etc,) but those features are _not_ being used here, but could be used in followup PRs if component teams so desired. I did notice while working on this overall feature that many of our links do point to "outdated" pages, some with eye-catching notices declaring that the spec has been superseded. Determining how, when and where to update such links is beyond the scope of this PR.
>> 
>> Going forward, it is to be hoped that component teams will maintain the underlying links, and the URLs in `@spec` tags, such that if references to external specifications are updated, this will include updating the `@spec` tags.
>> 
>> To see the effect of all these new `@spec` tags, see http://cr.openjdk.java.net/~jjg/8296546/api.00/
>> 
>> In particular, see the new [External Specifications](http://cr.openjdk.java.net/~jjg/8296546/api.00/external-specs.html) page, which you can also find via the new link near the top of the [Index](http://cr.openjdk.java.net/~jjg/8296546/api.00/index-files/index-1.html) pages.
>
> Jonathan Gibbons has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove updates from unexported files

src/java.xml/share/classes/javax/xml/XMLConstants.java line 35:

> 33:  * @spec https://www.w3.org/TR/REC-xml-names Namespaces in XML 1.0 (Third Edition)
> 34:  * @spec https://www.w3.org/TR/xml-names11 Namespaces in XML 1.1 (Second Edition)
> 35:  * @spec https://www.w3.org/TR/xmlschema-1 XML Schema Part 1: Structures Second Edition

Hi Jon,

I would agree with what Alan said earlier that the @see ref can be dropped. This particular class (XMLConstants.java [1]) is a good example for that argument: in the resulting javadoc, 5 specs were listed in the "External Specifications" section, 6 in "See Also:", and then they were listed again for each field. That's a lot of duplicates. Adding to the confusion was that the @spec and @see were not always the same, e.g. @spec XML 1.0.
points to the fifth edition while @see second.

A minor comment is that the '@spec's were rendered in one line while the @see refs a list. I would see the later is easier to read.

[1] http://cr.openjdk.java.net/~jjg/8296546/api.00/java.xml/javax/xml/XMLConstants.html

-------------

PR: https://git.openjdk.org/jdk/pull/11073