Answer for this question about Gson: http://stackoverflow.com/questions/20442265/how-to-decode-json-with-unknown-field-using-gson. This demonstrates how to use custom deserialiser to parse a big list of properties of the same type but unknown/random/varying names. Besides JDK, depends on Guava library.

Question20442265.java

import com.google.common.base.Charsets;
import com.google.common.io.Files;
import com.google.gson.*;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import static com.google.gson.FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES;

/**
 * http://stackoverflow.com/questions/20442265/how-to-decode-json-with-unknown-field-using-gson
 *
 * @author: jonik, http://stackoverflow.com/users/56285/jonik
 * Date: 7.12.2013
 */
public class Question20442265 {

    public static void main(String[] args) throws IOException {
        // using this test JSON: https://www.dropbox.com/s/a89s0ysv2cr8w44/question20442264.json?dl=0
        File jsonFile = new File("src/gson/", "question20442264.json");
        String json = Files.toString(jsonFile, Charsets.UTF_8);

        GsonBuilder builder = new GsonBuilder();
        builder.registerTypeAdapter(CityList.class, new CityListDeserializer());
        Gson gson = builder.setFieldNamingPolicy(LOWER_CASE_WITH_UNDERSCORES).create();
        CityList list = gson.fromJson(json, CityList.class);

        System.out.println(list.cities);
    }

    private static class CityList  {
        List<City> cities;

        private CityList(List<City> cities) {
            this.cities = cities;
        }
    }

    private static class City    {
        String citiesId;
        String city;
        String regionName;
        // and so on


        @Override
        public String toString() {
            return "City{" +
                    "citiesId='" + citiesId + '\'' +
                    ", city='" + city + '\'' +
                    ", regionName='" + regionName + '\'' +
                    '}';
        }
    }

    private static class CityListDeserializer implements JsonDeserializer<CityList> {
        @Override
        public CityList deserialize(JsonElement jsonElement, Type type, JsonDeserializationContext context) throws JsonParseException {
            JsonObject object = jsonElement.getAsJsonObject();
            List<City> cities = new ArrayList<City>();
            for (Map.Entry<String, JsonElement> entry : object.entrySet()) {
//                System.out.println(entry.getKey() + " " + entry.getValue());
                // Use default deserialisation for City objects:
                City city = context.deserialize(entry.getValue(), City.class);
                cities.add(city);
            }
            return new CityList(cities);
        }
    }

}