FindByObject returns null even when record is in the db - spring-boot

Question

In a springboot application I create a Game, with a list-of-cards converted in a large String.
The Game is related to a Player.
When I try to lookup the Game for a Player, the Springboot Hibernate app returns NULL . Why??!??
Now I want to create an endpoint to show a players game.
I cannot get it working, looking for a solution for days now...
The test I wrote shows the players, with game_ids, but when I try to FindByPlayer, the repository returns: null
The console shows:
=====================1
player = Player [id=234, game=Game [id=232, gameCards=nl.hu.bep2.casino.blackjack.domain.GameCards#c5092df, gameState=playing, numberOfDecks=1], user=nl.hu.bep2.casino.security.domain.User#1837c802]
=====================2
2023-02-17 18:33:45.333 DEBUG 2216 --- [nio-8080-exec-3] org.hibernate.SQL : select game0_.id as id1_2_, game0_.current_move as current_2_2_, game0_.game_cards as game_car3_2_, game0_.game_state as game_sta4_2_, game0_.number_of_decks as number_o5_2_ from game game0_ left outer join player player1_ on game0_.id=player1_.game_id where player1_.id=?
====================3
player =Player [id=234, game=Game [id=232, gameCards=nl.hu.bep2.casino.blackjack.domain.GameCards#c5092df, gameState=playing, numberOfDecks=1], user=nl.hu.bep2.casino.security.domain.User#1837c802]
speler: 234 heeft geen game
and postman shows:[ null ]
I use the following Classes:
Game
#Transactional
#Entity
#JsonIgnoreProperties({"player","dealer"})
public class Game {
#Id
#GeneratedValue
private long id;
#Convert(converter = CardListConverter.class)
#Column(length = 20000)
private GameCards gameCards;
#Enumerated(EnumType.STRING)
private GameState gameState;
#OneToOne(mappedBy="game", cascade = CascadeType.ALL)
private Player player;
#OneToOne(mappedBy="game", cascade = CascadeType.ALL)
private Dealer dealer;
private Move current_move;
private Integer numberOfDecks;
public Game() {
}
Player
#Transactional
#Entity
#JsonIgnoreProperties("game")
public class Player extends Hand implements Serializable{
#Id
#GeneratedValue
private long id;
//#JsonManagedReference
#OneToOne(fetch=FetchType.EAGER)
#JoinColumn(name="game_id")
private Game game;
#ManyToOne(fetch = FetchType.EAGER)
private User user; // niet via id koppelen aan een object, user heeft de link naar gepersisteerde chips. dit private object wordt in de applicatielaag gevuld met de chips van de user
//dependency injection van chips in player in applicatielaag, blackjackservice, startgame
public Player(){
}
public Player(User user, Game game) {
super();
this.user = user;
this.game=game;
}
GameRepository
public interface GameRepository extends JpaRepository<Game, Long>{
Game findByPlayer(Player player);
}
GamesService
#Service
public class GamesService {
#Autowired
private GameRepository gameRepository;
#Autowired
private UserService userService;
#Autowired
private PlayerService playerService;
public GamesService(){
}
public List<Game> GetGamesByUsername(String username) {
List<Game> gameList = new ArrayList<>();
List<Player> players = this.playerService.GetPlayerByUsername(username);
for
( Player p : players) {
System.out.println("=====================1");
System.out.println("player = "+ p);
System.out.println("=====================2");
Game game = this.gameRepository.findByPlayer(p);
gameList.add(game);
System.out.println("====================3"); System.out.println("player ="+
p);
if (game != null) { System.out.println("speler: "+ p.getId() +
" /n vinden we game " + game.getId()); }else{
System.out.println("speler: "+ p.getId() + " heeft geen game"); }
}
return gameList;
}
}
GamesController
#RestController
#RequestMapping("/game")
public class GamesController {
private final GamesService service;
// SameService injecteren, en service noemen
public GamesController(GamesService service) {
this.service = service;
}
#PostMapping("/showgames")
#ResponseBody
public List<Game> getGames(Authentication authentication, UserService userService){
UserProfile profile = (UserProfile) authentication.getPrincipal();
try {
List<Game> gameList = new ArrayList<>();
String username = profile.getUsername();
gameList = this.service.GetGamesByUsername(username);
return gameList;
} catch (NegativeNumberException exception) {
throw new ResponseStatusException(HttpStatus.BAD_REQUEST, exception.getMessage());
}
}
}
Also there is a User connected to the player, that works fine
Playerservice works fine:
#Service
public class PlayerService {
#Autowired
private PlayerRepository playerRepository;
#Autowired
private UserService userService;
public List<Player> GetPlayerByUsername(String username) {
User user = userService.loadUserByUsername(username);
List<Player> players = playerRepository.findByUser(user);
return players;
}

Answer 1

If player has game_id, then you may try to reach Game by id as shown below:
public interface GameRepository extends JpaRepository<Game, Long>{
Optional<Game> findById(Long id);
}
Then pass the player.getGameId() to the repository instead of Player.