An illegal reflective access operation has occurred on application start

[foal]

Describe the bug
On an application start I see the following

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.esotericsoftware.kryo.serializers.CachedFields (file:/Users/mailo/.m2/repository/com/esotericsoftware/kryo/5.3.0/kryo-5.3.0.jar) to field java.util.concurrent.atomic.AtomicLong.value
WARNING: Please consider reporting this to the maintainers of com.esotericsoftware.kryo.serializers.CachedFields
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

Environment:

• OS: [e.g. Windows]
• JDK Version: [e.g. 11]
• Kryo Version: [e.g. 5.3.0]

[theigl]

@foal: Kryo is missing safe serializers for a couple JDK types. AtomicLong is one of them. I'm planning to add the missing serializers to Kryo 5, but we unfortunately cannot register them by default, because it would break backwards compatibility. You can either ignore the warning for now, or register a custom serializer like this:

	/** Serializer for {@link AtomicLong} */
	public static class AtomicLongSerializer extends Serializer<AtomicLong> {
		public void write (Kryo kryo, Output output, AtomicLong object) {
			output.writeLong(object.get());
		}

		public AtomicLong read (Kryo kryo, Input input, Class<? extends AtomicLong> type) {
			return new AtomicLong(input.readLong());
		}

		public AtomicLong copy (Kryo kryo, AtomicLong original) {
			return new AtomicLong(original.get());
		}
	}

[theigl]

Other types missing safe serializers are discussed in #885