Android : Android: Custom serialization json using gson library

I'm a beginner android developer, help deal with the serialization of the json response from the server

    {"resources": {"1": {"res-id": "11886", "duration": "00:30"},
                   "2": {"res-id": "13451", "duration": "00:30"},
                   "3": {"res-id": "13452", "duration": "00:30"},
                           .... end more items...}

(this is a real response from the server :() in object

   ArrayList <Resources> resources;

I ran into a problem, since objects are not nested array. using gson library. google translate.