线程异常 "main" java.util.NoSuchElementException 扫描器错误

Question

我遇到了这个错误，不知道如何解决。 class导师想不通。这是一个发牌的扑克程序，允许用户更换最多 4 张牌，然后对其进行分析。它的设计目的是让用户可以随心所欲地玩很多手牌，但是输入决定他们是否玩的扫描仪不工作，我不明白为什么。

这里是主要代码

import java.util.*;
public class Poker
{
    public static void main(String[] args)
    {
        String game = "continue";
        Run runpoker = new Run();

        System.out.println("Enter 2 to play a hand or 1 to quit the game: ");
        while (game == "continue")
        {
            game = ((Run)runpoker).playhand();//this is line 18

        }

    }
}

这里是调用的方法playhand，才是真正的主要代码

import java.util.Scanner;
public class Run 
{
    public String playhand()
    {
        int r = 1;
        int limit = 0;

        // create a new, shuffled Deck
        Deck d = new Deck();
        Hand h = d.deal();
        h.sort();
        System.out.println(h);
        System.out.println("Which cards would you like to replace, up to 4");
        System.out.println("Enter 0 when finished");
        Scanner in = new Scanner(System.in);
        r = in.nextInt();
        while (r > 0 && r < 6 && limit < 4)
        {
            if (r > 0)
                h.replace(d, r - 1);
            limit++;
            r = in.nextInt();
        }
        h.sort();
        System.out.println(h);

        String result = h.analyze();
        System.out.println(result);
        String answer;
        System.out.println("Would you like to play again? Enter 'continue' to play again or 'quit' to stop playing: ");
        in.close();
        Scanner input = new Scanner(System.in);
        answer = input.nextLine();//this is line 34
        input.close();
        return answer;
    }
}

还有其他 classes 但它们应该不会影响扫描仪。这是错误

   Exception in thread "main" java.util.NoSuchElementException: No line found
        at java.util.Scanner.nextLine(Unknown Source)
        at Run.playhand(Run.java:34)
        at Poker.main(Poker.java:18)

Answer 1

在

之后按下初始回车 return

System.out.println("Enter 2 to play a hand or 1 to quit the game: ");
while ((game = scan.nextInt()) == 2)

永远不会消耗，并且在调用 playHand 时仍在输入中。

所以在调用 playHand 之前调用 scan.nextLine();

线程异常 "main" java.util.NoSuchElementException 扫描器错误

Exception in thread "main" java.util.NoSuchElementException Scanner error

java

poker

nosuchelementexception