JDK 25 compatibility

[mrniko]

Describe the bug
JDK 25 reports warnings:

WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
2025-12-23T20:48:33.210463889Z WARNING: sun.misc.Unsafe::arrayBaseOffset has been called by com.esotericsoftware.kryo.unsafe.UnsafeUtil (file:/application/BOOT-INF/lib/kryo-5.6.2.jar)
2025-12-23T20:48:33.210466222Z WARNING: Please consider reporting this to the maintainers of class com.esotericsoftware.kryo.unsafe.UnsafeUtil
2025-12-23T20:48:33.210467514Z WARNING: sun.misc.Unsafe::arrayBaseOffset will be removed in a future release

To Reproduce

        Kryo5Codec cc = new Kryo5Codec();
        cc.getValueEncoder().encode("123123");

Environment:

• OS: Any
• JDK Version: 25
• Kryo Version: 5.6.2

Additional context
Redisson lib

[theigl]

Kryo 5 still supports Java 8 and the migration path for this involves VarHandles that are only available since JDK9. I will target this for Kryo 6.

[KarstenSchmid]

Is there an ETA for Kryo 6?

[licenziato]

Any news about it? Is the project still active or we should move to something else?

Thanks