使用扫描仪时出现 java.util.NoSuchElementException

Question

因此，在调用我将在下面发布的函数(在我的主函数中)之后，在同一主函数中创建新的扫描仪对象不起作用，并给出了以下错误:

Exception in thread "main" java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:862)
at java.util.Scanner.next(Scanner.java:1485)
at java.util.Scanner.nextInt(Scanner.java:2117)
at java.util.Scanner.nextInt(Scanner.java:2076)

将我链接到此代码中的最后一行:

    int numHouse = 0;
    int numSeed = 0;
    System.out.println("Enter the total number of houses on the board: ");
    Scanner houseInput = new Scanner(System.in);
    numHouse = houseInput.nextInt();

它放置在我调用该函数之后(我稍后在上面的代码中关闭了扫描仪)。当我注释掉调用该函数时，该扫描仪可以工作，因此该函数中的某些内容会导致扫描仪出现错误。我花了几个小时寻找但无法解决它，如果有人可以的话，我将不胜感激。功能:

    public void InitializePlayers() {
    //change numPlayers to variable that contains number of players
    boolean validInput = false;
    do {
        System.out.print("Enter Number of Players (1/2): ");
        Scanner userInput = new Scanner(System.in); 
        int numPlayers = userInput.nextInt();
        System.out.print("\n");
        if(numPlayers == 1) {
            //One Human Player, One AI Player
            System.out.println("Single Player Selected");
            validInput = true;
            System.out.print("\n");             
            System.out.print("Enter Player One Name: ");

            //Initialize Player 1
            String p0_name = userInput.next();
            Player Human1 = new Player(p0_name,0,false);
            this.setPlayer0(Human1);

            //Initialize AI
            String AI_name = "Hal";
            Player AI = new Player(AI_name,1,true);
            this.setPlayer1(AI);
            userInput.close();
        }
        else if(numPlayers == 2){
            //Two Human Players
            System.out.println("Two Players Selected");
            validInput = true;
            System.out.print("Enter Player One Name: ");

            //Initialize Player 1
            String p0_name = userInput.next();
            Player Human1 = new Player(p0_name,0,false);
            this.setPlayer0(Human1);

            //Initialize Player 2
            System.out.print("Enter Player Two Name: ");
            String p1_name = userInput.next();
            Player Human2 = new Player(p1_name,0,false);
            this.setPlayer1(Human2);
            userInput.close();
        }
        else {
            System.out.println("Error, Player 1 Not set!");
            userInput.close();
        }
    }while(!validInput);
}

(测试时我总是输入 2)我尝试删除 do-while 循环，但这并没有解决问题。谢谢

Answer 1

如果可以使用一个扫描仪从 System.in 读取整个应用程序就更好了

关闭接受播放器的扫描仪将关闭InputStream，这将导致此NoSuchElmentException。如果您可以定义一个扫描仪并在接受输入的两种情况下使用它，那就更好了