使用扫描仪时java.util.NoSuchElementException

Question

因此，在调用下面将发布的函数(在main中)之后，在同一个main中创建一个新的扫描对象无效，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)

将我链接到这段代码中的最后一行：

    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();

它就放在我调用函数之后(我会在后面的代码中关闭扫描器)。当我注释掉调用这个函数时，这个扫描器可以工作，所以函数中的某些东西会导致扫描仪中的一个错误。我花了好几个小时寻找，但无法解决，如果有人可以的话，我会非常感激的。职能：

    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)我尝试过删除do-while循环，但这并没有解决问题。谢谢

Answer 1

更好的是，如果可以使用一个扫描仪从System.in中读取整个应用程序

关闭接收播放机的扫描器将关闭InputStream，这将导致NoSuchElmentException.Better，如果您可以定义一个扫描器，并在两次输入时使用它

Answer 2

就像另一个人说的，我终于发现了这个问题。关闭扫描仪一旦关闭InputStream，就不能再使用了。我必须在我的主屏幕开始时做一个扫描器，并将它传递给所有需要它的函数。我从每个函数中删除了所有的闭包，并在main的末尾关闭。