RFR: 8362637: Convert java.nio.ByteOrder to an enum

[Chen Liang]

On Mon, 6 Oct 2025 18:21:26 GMT, Roger Riggs <rriggs at openjdk.org> wrote:

> Convert java.nio.ByteOrder to an enum.
> The class declaration is changed from `public class` to `public enum`.
> Enums are `Comparable` so declare LITTLE_ENDIAN before BIG_ENDIAN so LITTLE_ENDIAN is less than BIG_ENDIAN. 
> The implementation is simplified, removing the constructor and explicit static fields. 
> Remove the override of `toString`; the javadoc provided by Enum is sufficient.
> 
> No changes to other classes or implementations are needed to pass Tier 1-3.

Thanks for this interesting interpretation, Alan. Looks good. Some bikeshedding attached.

src/java.base/share/classes/java/nio/ByteOrder.java line 38:

> 36:  */
> 37: 
> 38: public enum ByteOrder  {

Suggestion:

public enum ByteOrder {

src/java.base/share/classes/java/nio/ByteOrder.java line 45:

> 43:      */
> 44:     LITTLE_ENDIAN,
> 45:     /**

Suggestion:

    LITTLE_ENDIAN,

    /**

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

Marked as reviewed by liach (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27657#pullrequestreview-3309910954
PR Review Comment: https://git.openjdk.org/jdk/pull/27657#discussion_r2410481352
PR Review Comment: https://git.openjdk.org/jdk/pull/27657#discussion_r2410483570