RFR: JDK-8322878: Including sealing information Class.toGenericString()

[Roger Riggs]

On Wed, 3 Jan 2024 06:43:22 GMT, Joe Darcy <darcy at openjdk.org> wrote:

> As recently discussed on core libs, sealed-ness information could be included in the Class.toGenericString() output, analagous to how "modifiers" that also correspond to JVM access flags are handled.
> 
> This is the initial spec, implementation, and test updated needed for that change. If there is consensus this is a reasonable direction, I'll create the CSR, etc.

LGTM

src/java.base/share/classes/java/lang/Class.java line 264:

> 262:     /**
> 263:      * Returns a string describing this {@code Class}, including
> 264:      * information about modifiers, {@linkplain #isSealed() sealing}, and type parameters.

If Class.toGenericString is a useful API point for describing the blessed order of modifiers in the JDK
perhaps the existing classes that describe modifiers could/should cross reference this method.

src/java.base/share/classes/java/lang/Class.java line 320:

> 318:                 // sufficient to check for sealed-ness after all
> 319:                 // modifiers are printed.
> 320:                 boolean isSealed = isSealed();

A small concern about performance.  
Class.isSealed() calls getPermittedSubclasses() which assembles and filters the list of classes and a possible security manager check and then only checks for non-null.
Perhaps a separate issue could look at that.

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Marked as reviewed by rriggs (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17239#pullrequestreview-1802318323
PR Review Comment: https://git.openjdk.org/jdk/pull/17239#discussion_r1440551717
PR Review Comment: https://git.openjdk.org/jdk/pull/17239#discussion_r1440543767