デリミタとしての空白文字の連結

Question

コード内の2番目の区切り文字に何が間違っているかについての洞察がありますか？私は、コードやカンマで区切りの数字、または空白やカンマを実行すると、それは完全に正常に動作しますが、私は、単一の空白とそれを実行しようとすると、私はこのエラーを取得する：

Exception in thread "main" java.util.InputMismatchException 
    at java.util.Scanner.throwFor(Unknown Source) 
    at java.util.Scanner.next(Unknown Source) 
    at java.util.Scanner.nextInt(Unknown Source) 
    at java.util.Scanner.nextInt(Unknown Source) 
    at main.Mean.main(Mean.java:28) 

マイコード：

package main; 

import java.util.Scanner; 

public class Mean { 
    @SuppressWarnings("resource") 
    public static void main (String [] args){ 
     // Console prompts use to enter their numbers 
     System.out.println("Please Enter your Numbers: "); 

     // Creating a String of numbers that will be stored in the 'nums' variable 
     Scanner nums = new Scanner(System.in); 

     // Making 'input' equal to the 
     String input = nums.nextLine(); 

     // Now the scanner class scans the string that was put into the variable 'input'. 
     Scanner scan = new Scanner(input); 

     scan.useDelimiter(",");    // Any commas are now a delimiter 
     scan.useDelimiter("\\s*");   // Any combination of concatenated of whitespace is now a delimiter 
     scan.useDelimiter("\\s*,\\s*");  // Any combination of concatenated of whitespace followed by a single comma followed by any number of concatenated whitespace is now a delimeter 

     double total = 0.0;     // Initializing the variable total and setting it equal to 0.0 
     double counter = 0.0;    // Initializing the variable counter and setting it equal to 0.0 

     while(scan.hasNextLine()){   // While the variable 'scan' still has integers left... 
      total += scan.nextInt();  // Make the total equal to the old total plus the new presented integer 
      counter++;      // Add one to the 'counter' variable to keep track of the total amount of numbers 

      //System.out.println("Total: "+total);  Commented out code that was used for testing 
      //System.out.println("Counter: "+counter); Commented out code that was used for testing 
     } 
     scan.close();      // Closes the scanner 

     double mean = total/counter;  // Mean is equal to the total divided by the amount of numbers 
     System.out.println(); 
     System.out.println("Average: " + mean); 
    } 
} 

Answer 1

区切り文字を積み重ねないでください。あなただけの最後のパターンを使用しているので、それが正常に動作し

scan.useDelimiter("\\s*,\\s*|\\s*"); 

Answer 2

例外そのものの説明自体です。必ず、APIドキュメントを参照してください。

https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#nextInt()

public int nextInt()

Scans the next token of the input as an int. An invocation of this method of the form nextInt() behaves in exactly the same way as the invocation nextInt(radix), where radix is the default radix of this scanner.

Returns: the int scanned from the input

Throws:

InputMismatchException - if the next token does not match the Integer > regular expression, or is out of range

NoSuchElementException - if input is exhausted

IllegalStateException - if this scanner is closed