java - Spring Rest Controller Return Specific Fields -

i've been going through head best way design json api using spring mvc. know io expensive, , don't want make client make several api calls need. @ same time don't want return kitchen sink.

as example working on game api similar imdb video games instead.

if returned connected game this.

/api/game/1

{     "id": 1,     "title": "call of duty advanced warfare",     "release_date": "2014-11-24",     "publishers": [         {             "id": 1,             "name": "activision"         }     ],     "developers": [         {             "id": 1,             "name": "sledge hammer"         }     ],     "platforms": [         {             "id": 1,             "name": "xbox one",             "manufactorer": "microsoft",             "release_date": "2013-11-11"         },         {             "id": 2,             "name": "playstation 4",             "manufactorer": "sony",             "release_date": "2013-11-18"         },         {             "id": 3,             "name": "xbox 360",             "manufactorer": "microsoft",             "release_date": "2005-11-12"         }     ],     "esrbrating": {         "id": 1,         "code": "t",         "name": "teen",         "description": "content suitable ages 13 , up. may contain violence, suggestive themes, crude humor, minimal blood, simulated gambling and/or infrequent use of strong language."     },     "reviews": [         {             "id": 1,             "user_id": 111,             "rating": 4.5,             "description": "this game awesome"         }     ] } 

however may not need information, again might. making calls seems bad idea i/o , performance.

i thought doing specifying include parameter in requests.

now example if did not specify includes following.

{     "id": 1,     "title": "call of duty advanced warfare",     "release_date": "2014-11-24" } 

however want information requests this.

/api/game/1?include=publishers,developers,platforms,reviews,esrbrating 

this way client has ability specify how information want. i'm kind of @ loss best way implement using spring mvc.

i'm thinking controller this.

public @responsebody game getgame(@pathvariable("id") long id,      @requestparam(value = "include", required = false) string include)) {          // check include params present          // filtering? } 

i'm not sure how optionally serialize game object. possible. best way approach in spring mvc?

fyi, using spring boot includes jackson serialization.

instead of returning game object, serialize as map<string, object>, map keys represent attribute names. can add values map based on include parameter.

@responsebody public map<string, object> getgame(@pathvariable("id") long id, string include) {      game game = service.loadgame(id);     // check `include` parameter , create map containing required attributes     map<string, object> gamemap = service.convertgametomap(game, include);      return gamemap;  } 

as example, if have map<string, object> this:

gamemap.put("id", game.getid()); gamemap.put("title", game.gettitle()); gamemap.put("publishers", game.getpublishers()); 

it serialized this:

{   "id": 1,   "title": "call of duty advanced warfare",   "publishers": [     {         "id": 1,         "name": "activision"     }   ] }