SetSerializer.java

package de.javakaffee.kryoserializers.dexx;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.Serializer;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;

import com.github.andrewoma.dexx.collection.Builder;
import com.github.andrewoma.dexx.collection.Set;
import com.github.andrewoma.dexx.collection.Sets;

/**
* A kryo {@link Serializer} for dexx {@link Set}
 */
public class SetSerializer extends Serializer<Set<Object>> {

    private static final boolean DOES_NOT_ACCEPT_NULL = false;
    private static final boolean IMMUTABLE = true;

    public SetSerializer() {
        super(DOES_NOT_ACCEPT_NULL, IMMUTABLE);
    }

    @Override
    public void write(Kryo kryo, Output output, Set<Object> object) {
        output.writeInt(object.size(), true);
        for (Object elm : object) {
            kryo.writeClassAndObject(output, elm);
        }
    }

    @Override
    public Set<Object> read(Kryo kryo, Input input, Class<Set<Object>> type) {
        final int size = input.readInt(true);
        Builder<Object, Set<Object>> builder = Sets.builder();
        for (int i = 0; i < size; ++i) {
            builder.add(kryo.readClassAndObject(input));
        }
        return builder.build();
    }

    /**
     * Creates a new {@link ImmutableSetSerializer} and registers its serializer
     * for the several ImmutableSet related classes.
     *
     * @param kryo the {@link Kryo} instance to set the serializer on
     */
    public static void registerSerializers(final Kryo kryo) {

        final SetSerializer serializer = new SetSerializer();

        kryo.register(Set.class, serializer);

        // Note:
        //  Only registering above is good enough for serializing/deserializing.
        //  but if using Kryo#copy, following is required.

        kryo.register(Sets.of().getClass(), serializer);
        kryo.register(Sets.of(1).getClass(), serializer);
        kryo.register(Sets.of(1,2,3).getClass(), serializer);
        kryo.register(Sets.of(1,2,3,4).getClass(), serializer);
        kryo.register(Sets.of(1,2,3,4,5).getClass(), serializer);
        kryo.register(Sets.of(1,2,3,4,5,6).getClass(), serializer);
        kryo.register(Sets.of(1,2,3,4,5,6,7).getClass(), serializer);
        kryo.register(Sets.of(1,2,3,4,5,6,7,8).getClass(), serializer);
        kryo.register(Sets.of(1,2,3,4,5,6,7,8,9).getClass(), serializer);
        kryo.register(Sets.of(1,2,3,4,5,6,7,8,9,10).getClass(), serializer);
        kryo.register(Sets.of(1,2,3,4,5,6,7,8,9,10,11).getClass(), serializer);

    }
}