添加到同一个数组列表的两种方法获取扫描仪错误

Question

我正在为最终项目编写游戏。游戏的目标是获得尽可能多的猫。养猫的一种方法是收养它。所以我有以下方法：

    public void adoptCat()
    {
        Scanner keyboard = new Scanner(System.in);

        catCounter++;

        System.out.println("You just adopted a cat! It needs a name. "
            + "Please enter in a name for your new cat: ");
        String catName = keyboard.nextLine();
        catNames.add(catName);
        catHealth.add(100);

        scoreCounter = scoreCounter + 10;
        keyboard.close();
    }

当我打印出 arraylist 时，第一种方法可以正常工作。但是，一旦我调用另一种方法，它就会给我一个错误，说找不到行。我想知道我是否需要先以某种方式冲洗扫描仪，或者为什么它不允许我输入第二个名称。这是我到目前为止的代码：

public class Agnus 
{
        private int catCounter = 0;
        private int scoreCounter = 0;

        private ArrayList<String> catNames = new ArrayList<>();
        private ArrayList<Integer> catHealth = new ArrayList<>();


    public void findStray()
    {
        Scanner keyboard = new Scanner(System.in);

        catCounter++;

        System.out.println("You just found a feral cat! It needs a name. "
            + "Please enter in a name for your new cat: ");
        String name = keyboard.nextLine();
        catNames.add(name);
        catHealth.add(100);     

        scoreCounter = scoreCounter + 5;
        keyboard.close();
    }

    public void adoptCat()
    {
        Scanner keyboard = new Scanner(System.in);

        catCounter++;

        System.out.println("You just adopted a cat! It needs a name. "
            + "Please enter in a name for your new cat: ");
        String name = keyboard.nextLine();
        catNames.add(name);
        catHealth.add(100);

        scoreCounter = scoreCounter + 10;
        keyboard.close();
    }

    public void stealCat()
    {
        Scanner keyboard = new Scanner(System.in);

        catCounter++;

        System.out.println("You just stole your neighbors cat! It needs"
            + " a new name. Please enter in a name for your new cat: ");
        String name = keyboard.nextLine();
        catNames.add(name);
        catHealth.add(100);

        scoreCounter = scoreCounter + 20;
        keyboard.close();
    }
}

演示代码如下所示：

public class AgnusDemo 
{

    public static void main(String[] args)
    {
        Agnus agnus = new Agnus();

        agnus.adoptCat();
        System.out.println(agnus);

        agnus.stealCat();
        System.out.println(agnus);


    }
}

这是我得到的错误：

You just adopted a cat! It needs a name. Please enter in a name for your new cat: 
James
Here are all your cat's names and their health: 
[James] ---> [100]
You just stole your neighbors cat! It needs a new name. 
Please enter in a name for your new cat: 
Exception in thread "main" java.util.NoSuchElementException: No line found
    at java.util.Scanner.nextLine(Scanner.java:1540)
    at Agnus.stealCat(Agnus.java:78)
    at AgnusDemo.main(AgnusDemo.java:12)

我希望我尽可能清楚地说明这一点。希望我提供了足够的信息。如果不让我知道。感谢您能给我的任何帮助！

米什

Answer 1

尝试在类级别创建 扫描仪对象。

import java.util.ArrayList;
import java.util.Scanner;

public class Agnus {
    private int catCounter = 0;
    private int scoreCounter = 0;

    private ArrayList<String> catNames = new ArrayList<>();
    private ArrayList<Integer> catHealth = new ArrayList<>();

    Scanner keyboard = new Scanner(System.in);//<-- create the scanner   
                                              //object at class level

public void findStray()
{


    catCounter++;

    System.out.println("You just found a feral cat! It needs a name. "
        + "Please enter in a name for your new cat: ");
    String name = keyboard.nextLine();
    catNames.add(name);
    catHealth.add(100);     

    scoreCounter = scoreCounter + 5;

}

public void adoptCat()
{


    catCounter++;

    System.out.println("You just adopted a cat! It needs a name. "
        + "Please enter in a name for your new cat: ");
    String name = keyboard.nextLine();
    catNames.add(name);
    catHealth.add(100);

    scoreCounter = scoreCounter + 10;

}

public void stealCat()
{


    catCounter++;

    System.out.println("You just stole your neighbors cat! It needs"
        + " a new name. Please enter in a name for your new cat: ");

    String name = keyboard.next();
    catNames.add(name);
    catHealth.add(100);

    scoreCounter = scoreCounter + 20;

    }
}