Example of how IAP/ION codec for jvm-serializers could look like

IapDatabind.java

package serializers;

import java.util.Arrays;

import com.jenkov.iap.ion.read.IonObjectReader;
import com.jenkov.iap.ion.write.IonObjectWriter;

import data.media.MediaContent;

/**
 * Codec for ION/IAP.
 */
public class IapDatabind
{
    public static void register(TestGroups groups) {
        groups.media.add(JavaBuiltIn.mediaTransformer, new IapSerializer<MediaContent>(MediaContent.class),
                new SerFeatures(
                        SerFormat.BIN_CROSSLANG,
                        SerGraph.FLAT_TREE,
                        SerClass.ZERO_KNOWLEDGE,
                        ""
                )
        );
    }

    public final static class IapSerializer<T> extends Serializer<T>
    {
        private final IonObjectWriter writer;
        private final IonObjectReader reader;
        
        protected IapSerializer(Class<T> t)
        {
            reader = new IonObjectReader(t);
            writer = new IonObjectWriter(t);
        }

        @Override
        public String getName() { return "iap/databind"; }

        @SuppressWarnings("unchecked")
        @Override
        public T deserialize(byte[] array) throws Exception {
            return (T) reader.read(array, 0);
        }

        @Override
        public byte[] serialize(T content) throws Exception {
            // really should not assume known output length but...
            byte[] buffer = new byte[512]; // just because we know it'll fit, for now
            int end = writer.writeObject(content, 2, buffer, 0);
            return Arrays.copyOf(buffer, end);
        }
    }
}