Question

我的代码在使用扫描仪的每一行上都给我一个NoSuchElementException。我的其余代码工作正常。

import java.io.*;
import java.util.*;
import java.util.StringTokenizer;
import java.util.Scanner;

public class Store
{

 public static void main(String [] args)
{
  Scanner nameScanner = new Scanner(System.in);
  System.out.println (); 
  System.out.println ("Enter your name: "); 
  String name = nameScanner.next();  

  Scanner whatToBuy = new Scanner (System.in);
  System.out.println (); 
  System.out.println ("What would you like to purchase from the store? Please list your items separated by commas: "); 
  String purchase = whatToBuy.nextLine();    


  Scanner howManyToBuy = new Scanner (System.in);
  System.out.println (); 
  System.out.println ("How many would you like to purchase from each item? You must purhase more than one of each item. Please list your items separated by commas. : "); 
  String howMany = howManyToBuy.nextLine();
}

 }

谢谢！

Answer 1

您的代码没有问题，您可以显示跟踪吗？ java.util.StringTokenizer有问题吗？顺便说一句，您只能使用一个Scanner实例。例如

import java.io.*;
import java.util.*;
import java.util.StringTokenizer;
import java.util.Scanner;

public class Store {

    public static void main(String[] args) {
        try(Scanner scanner = new Scanner(System.in)){
            System.out.println();
            System.out.println("Enter your name: ");
            String name = scanner.next();
            System.out.println();
            System.out.println(
                    "What would you like to purchase from the store? Please list your items separated by commas: ");
            String purchase = scanner.next();
            System.out.println();
            System.out.println(
                    "How many would you like to purchase from each item? You must purhase more than one of each item. Please list your items separated by commas. : ");
            String howMany = scanner.next();
            System.out.printf("name:%s purchase:%s howMany:%s",name,purchase,howMany);
        }

    }

}

Answer 2

许多IDE不提供标准输入流。执行窗口是一个虚拟环境，其中Java应用程序在后台运行，其输出被捕获并显示在窗口中，但是没有输入（没有System.in）。尝试在命令提示符窗口（在Windows中）或Shell终端窗口（在Mac中）中运行应用程序。

扫描仪上的NoSuchElementException

2 个答案: