You can get direct Alice as below
JsonParserjsonParser = new JsonParser();
JsonElement jsonElement = jsonParser.parse(YOUR_JSON_STRING_HERE);
// get JsonElement for Alice as like this
JsonElement aliceJsonElement = jsonElement.getAsJsonObject().get("Alice");
It will give you this json object {"location":"New York"}
Finally you can parse it as
Gson gson = new Gson();
Type mapType = new TypeToken<Map<String, String>>(){}.getType();
Map<String, String> map = gson.fromJson(aliceJsonElement, mapType);
// iterate map
Like this you can get Bob AND following
jsonElement.getAsJsonObject().get("Bob")
jsonElement.getAsJsonObject().get("Bob").getAsJsonObject().get("following")