import com.google.gson.Gson;

public class GsonTypeTest {
    static class L { public long value; }
    static class D { public double value; }

    public static void main(String[] args) {
        Gson g = new Gson();
        String json = "{\"value\": \"１２３４５６\"}";

        System.out.println("long:   " + g.fromJson(json, L.class).value);
        System.out.println("double: " + g.fromJson(json, D.class).value);
    }
}