Graphql null 指針異常即使不是 null

Question

我正在嘗試使用 createPlayer 突變創建一個播放器。 我輸入了 playerDTO 的參數，但我得到了 null 指針異常

Cannot invoke "com.example.basketballteam.dto.PlayerDTO.getName()" because "playerdto" is null

這是我的突變：

input PlayerDTO{
    name:String!,
    lastName:String!,
    position:Position!
}
type Mutation{
    createPlayer(plyr: PlayerDTO):Player
    deletePlayer(id: ID):Boolean
    addPlayerToTeam(id:ID,tid:ID):Player
}

這是我的 controller

  @MutationMapping
    public Player createPlayer(@Argument PlayerDTO playerdto){
        return playerRepository.save(playerMapper.ToEntity(playerdto));
    }

這是我的映射器：

  public Player ToEntity(PlayerDTO playerdto){
        Player player = new Player();
        player.setName(playerdto.getName());
        player.setLastName(playerdto.getLastName());
        player.setPosition(playerdto.getPosition());

        return player;
    }

Answer 1

graphql 模式（Mutation 類型）中的名稱必須與 controller 中的數據傳輸 object 參數相同

input PlayerDTO{
    name:String!,
    lastName:String!,
    position:Position!
}

type Mutation{
    createPlayer(player: PlayerDTO):Player
    deletePlayer(id: ID):Boolean
    addPlayerToTeam(id:ID,tid:ID):Player
}

有了這個 controller 它應該可以工作

  @MutationMapping
  public Player createPlayer(@Argument PlayerDTO player){
    return playerRepository.save(playerMapper.ToEntity(player));
  }