运行时错误--线程"main"中的异常java.util.InputMismatchException

Question

我很难理解这个代码有什么问题。Dr.Java一切都很好，但是在另一个名为edhesive的代码运行平台上（我就是在这个平台上被分配这个项目的），它给我一个错误。我已经检查了所有我认为出错的地方，但仍然不知道哪里出了问题。

import java.util.Scanner;

public class Main
{
     public static void main(String[] args)
     {
          Scanner scan = new Scanner(System.in);
          System.out.println("Welcome. What is your name?");
          String name = scan.next();

          System.out.println("Hello " + name + ". Try your best to crack the code!");

          System.out.println("PHASE 1");
          System.out.println("Enter a number:");
          int phaseOneNum = scan.nextInt();

          if (phaseOneNum == 3)
          {
               System.out.println("Correct!");

               System.out.println("PHASE 2");
               System.out.println("Enter a number:");
               int phaseTwoNum = scan.nextInt();

               if (phaseTwoNum == 1 || (phaseTwoNum > 33 && phaseTwoNum<= 100))
               {
                    System.out.println("Correct!");

                    System.out.println("PHASE 3");
                    System.out.println("Enter a number:");
                    int phaseThreeNum = scan.nextInt();

                    if (phaseThreeNum > 0 && ((phaseThreeNum % 3 == 0) || (phaseThreeNum % 7 == 0)))
                    {
                      System.out.println("Correct!");
                      System.out.println("You have cracked the code!");
                    }

                    else
                    {
                         System.out.println("Sorry, that was incorrect!");
                         System.out.println("Better luck next time!");
                    }
               }

               else
               {
                    System.out.println("Sorry, that was incorrect!");
                    System.out.println("Better luck next time!");
               }
          }

          else
          {
               System.out.println("Sorry, that was incorrect!");
               System.out.println("Better luck next time!");
          }
     }
}

在edhesive上运行后，我得到了这个错误

Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Scanner.java:864)
    at java.util.Scanner.next(Scanner.java:1485)
    at java.util.Scanner.nextInt(Scanner.java:2117)
    at java.util.Scanner.nextInt(Scanner.java:2076)
    at Main.main(Main.java:184)
    at Ideone.test(Main.java:111)
    at Ideone.test(Main.java:31)
    at Ideone.main(Main.java:23)

有人能帮帮我吗？

Answer 1

运行时错误-线程“main”java.util.InputMismatchException中出现异常

scan.nextInt（）；只接受整数，你可以传递字符串。所以，它给你java.util.InputMismatchException

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        System.out.println("Welcome. What is your name?");
        String name = scan.next();

        System.out.println("Hello " + name + ". Try your best to crack the code!");

        System.out.println("PHASE 1");
        System.out.println("Enter a number:");
        int phaseOneNum = 0;
        do {
            while (!scan.hasNextInt()) {
                System.out.println("That's not a number!");
                scan.next(); // this is important!
            }
            phaseOneNum = scan.nextInt();
        } while (phaseOneNum <= 0);

        if (phaseOneNum == 3) {
            System.out.println("Correct!");

            System.out.println("PHASE 2");
            System.out.println("Enter a number:");
            int phaseTwoNum;
            do {
                while (!scan.hasNextInt()) {
                    System.out.println("That's not a number!");
                    scan.next(); // this is important!
                }
                phaseTwoNum = scan.nextInt();
            } while (phaseTwoNum <= 0);

            if (phaseTwoNum == 1 || (phaseTwoNum > 33 && phaseTwoNum <= 100)) {
                System.out.println("Correct!");

                System.out.println("PHASE 3");
                System.out.println("Enter a number:");
                int phaseThreeNum;
        do {
            while (!scan.hasNextInt()) {
                System.out.println("That's not a number!");
                scan.next(); // this is important!
            }
            phaseThreeNum= scan.nextInt();
        } while (phaseThreeNum<= 0);

                if (phaseThreeNum > 0 && ((phaseThreeNum % 3 == 0) || (phaseThreeNum % 7 == 0))) {
                    System.out.println("Correct!");
                    System.out.println("You have cracked the code!");
                } else {
                    System.out.println("Sorry, that was incorrect!");
                    System.out.println("Better luck next time!");
                }
            } else {
                System.out.println("Sorry, that was incorrect!");
                System.out.println("Better luck next time!");
            }
        } else {
            System.out.println("Sorry, that was incorrect!");
            System.out.println("Better luck next time!");
        }
    }
}