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Custom codec not working after version 3.10.0

See original GitHub issue

We have been using a custom KryoCodec(overriding the built in one) for a while but after version 3.10.0 this no longer works. The change that affects us are introduced by the following commit: https://github.com/redisson/redisson/commit/37b58db7bcc2bdf586e3ce2e55a37803fcd545fd

I’ve spent a little bit of time looking into what’s going on and it looks like there are issues regarding classloading since we got all sorts of exceptions now, especially lots of com.esotericsoftware.kryo.KryoException: Unable to find class on classes that we have been serializing without problems til now. The root cause is of course java.lang.ClassNotFoundException:x.y.z

I’ve attached the relevant code with the working and non working solution:

Working:

public class KryoCodec extends org.redisson.codec.KryoCodec {

    private static class KryoPoolImpl extends org.redisson.codec.KryoCodec.KryoPoolImpl {

        KryoPoolImpl(List<Class<?>> classes, ClassLoader classLoader) {
            super(classes, classLoader);
        }

        @Override
        protected Kryo createInstance() {
            Kryo kryo = super.createInstance();
            kryo.setReferences(true);
            UnmodifiableCollectionsSerializer.registerSerializers(kryo);
            kryo.setInstantiatorStrategy(
                    new Kryo.DefaultInstantiatorStrategy(new StdInstantiatorStrategy())
            );
            return kryo;
        }

    }

    public KryoCodec() {
        this(Collections.emptyList());
    }

    public KryoCodec(ClassLoader classLoader) {
        this(Collections.emptyList(), classLoader);
    }

    public KryoCodec(List<Class<?>> classes) {
        this(classes, null);
    }

    public KryoCodec(List<Class<?>> classes, ClassLoader classLoader) {
        this(new KryoPoolImpl(classes, classLoader));
    }

    public KryoCodec(KryoPoolImpl kryoPool) {
        super(kryoPool);
    }

}

Non-working:

public class KryoCodec extends org.redisson.codec.KryoCodec {

    private final KryoPoolImpl kryoPool;

    private static class KryoPoolImpl extends org.redisson.codec.KryoCodec.KryoPoolImpl {

        KryoPoolImpl(List<Class<?>> classes, ClassLoader classLoader) {
            super(classes, classLoader);
        }

        @Override
        protected Kryo createInstance() {
            Kryo kryo = super.createInstance();
            kryo.setReferences(true);
            UnmodifiableCollectionsSerializer.registerSerializers(kryo);
            kryo.setInstantiatorStrategy(
                    new Kryo.DefaultInstantiatorStrategy(new StdInstantiatorStrategy())
            );
            return kryo;
        }

    }

    public KryoCodec() {
        this(Collections.emptyList());
    }

    public KryoCodec(ClassLoader classLoader) {
        this(Collections.emptyList(), classLoader);
    }

    public KryoCodec(ClassLoader classLoader, KryoCodec kryoCodec) {
        this(kryoCodec.kryoPool.getClasses(), classLoader);
    }

    public KryoCodec(List<Class<?>> classes) {
        this(classes, null);
    }

    public KryoCodec(List<Class<?>> classes, ClassLoader classLoader) {
        this(new KryoPoolImpl(classes, classLoader));
    }

    public KryoCodec(KryoPoolImpl kryoPool) {
        super(kryoPool);
        this.kryoPool = kryoPool;
    }

}

The only change on the latter is the addition of the new constructor which now is required.