RFR: 8355652: Parse ClassFileFormatVersion from ClassFileVersion

[simon]

On Mon, 21 Jul 2025 00:11:20 GMT, Chen Liang <liach at openjdk.org> wrote:

>> 8355652: add new method to return ClassFileFormatVersion from ClassFileVersion.
>> ---------
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>
> src/java.base/share/classes/jdk/internal/classfile/impl/ClassFileVersionImpl.java line 54:
> 
>> 52:     public Optional<ClassFileFormatVersion> formatVersion() {
>> 53:         try {
>> 54:             return Optional.of(ClassFileFormatVersion.fromMajor(majorVersion));
> 
> You should check the minor version to be 0 for major versions 54 and later.

Do you mean something like this? 


@Override
    public Optional<ClassFileFormatVersion> formatVersion() {
        if (majorVersion >= 54 || minorVersion == 0) {
            return Optional.empty();
        }
        try {
            return Optional.of(ClassFileFormatVersion.fromMajor(majorVersion));
        } catch (IllegalArgumentException e) {
            return Optional.empty();
        }
    }

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

PR Review Comment: https://git.openjdk.org/jdk/pull/26406#discussion_r2218024287