hasnext hang如何更正此错误[重复]

Question

import java.util.Arrays;
import java.util.Scanner;

public class Sort {

    public static void main(String[] args) {
        String temp = "";
        String a ="";

        String[] New;

        Scanner keyboard = new Scanner(System.in);
        //String s1 = new String(keyboard.nextLine());

        System.out.println("Please write your elements.");

        while(keyboard.hasNext()){          
            String currentString = keyboard.next();
            if(currentString.equals(" ")){
                System.out.println("Bye");
            }
            a += (currentString.charAt(0) + "").toUpperCase() + currentString.substring(1).toLowerCase()+",";
        }
        a = a.substring(0, a.length()-1);

        New = a.split(",");
        System.out.println("Your elements are" + Arrays.toString(New) + ".");

        for (int x = 1; x < New.length; x++) {
            for (int y = 0; y < New.length - x; y++) {
                if (New[y].compareTo(New[y + 1]) > 0) {
                    temp = New[y];
                    New[y] = New[y + 1];
                    New[y + 1] = temp;

                }
            }

        } for(int i=0;i<New.length;i++){
            System.out.println(New[i]);
        }
        /*System.out.println("In alphabethical order form is:");
        System.out.println(Arrays.toString(New));*/

    }
}

hasnext在infinite loop中已经搜索了stackowerflow但answers无法修复错误。请帮助我。这里是我的代码，请写出你的元素。

Fi press space和enter有一个问题。

线程“main”java.lang.StringIndexOutOfBoundsException中的Bye异常：字符串索引超出范围：aa.sort.main（sort.java:38)处的java.lang.String.SubString（未知源）处的-1

Answer 1

几件事。您应该使用HasNextLine()和NextLine()而不是HasNext()和Next()。

更改后，while循环永远不会结束，因为您只需打印bye并继续循环。在打印bye后添加break语句。

if(currentString.equals(" ")){
    System.out.println("Bye");
    break;
}