byte[] base64 encoder for Gson (showcase)

Document.java

package sample;

import com.google.gson.GsonBuilder;
import com.google.gson.TypeAdapter;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;
import java.io.IOException;
import java.util.Base64;
import org.immutables.gson.Gson;
import org.immutables.value.Value;

@Gson.TypeAdapters
@Value.Immutable
public abstract class Document {
	public abstract byte[] raw();

	public static void main(String... args) {
		com.google.gson.Gson gson =
				new GsonBuilder()
						.registerTypeAdapterFactory(new GsonAdaptersDocument())
						.registerTypeAdapter(byte[].class, new Base64TypeAdapter())
						.create();

		String json =
				gson.toJson(ImmutableDocument.builder()
						.raw(new byte[] {1, 2, 3, 4, 5})
						.build());

		System.out.println(json);
		// {"raw":"AQIDBAU"}
		Document document = gson.fromJson(json, ImmutableDocument.class);

		System.out.println(document);
		// Document{raw=[1, 2, 3, 4, 5]}
	}

	public static class Base64TypeAdapter extends TypeAdapter<byte[]> {
		@Override
		public void write(JsonWriter out, byte[] value) throws IOException {
			out.value(Base64.getEncoder().withoutPadding().encodeToString(value));
		}
		@Override
		public byte[] read(JsonReader in) throws IOException {
			return Base64.getDecoder().decode(in.nextString());
		}
	}
}