如何在这些方法中处理字符串输入？[副本]

Question

如何处理用户在下面的每个方法中输入字符串。我使用不同的建议尝试了很多次，错误一直在无限循环。如何强制用户输入int而不是字符串，方法是添加下面的方法，而不是在它们当前的状态下修改它们。

    private void readMonth(Scanner keyboardIn)
    {
        boolean success = false;
        while(!success)
        {   
            try
            {
                System.out.print("Enter the month the account opened: ");
                int m = keyboardIn.nextInt();
                dateOpened.setMonth(m);
                success = true;
            }catch(Exception e)
            {
                System.out.println(e.getMessage());
            }   
          } 
       }    


    // Enter the year, checking for errors
    private void readYear(Scanner keyboardIn)
    {
        boolean success = false;
        while(!success)
        {   
            try
            {
                System.out.print("Enter the year the account opened: ");
                int y = keyboardIn.nextInt();
                dateOpened.setYear(y);
                success = true;
            }catch(Exception e)
            {
                System.out.println(e.getMessage());
            }
        }
    }

Answer 1

当您尝试输入除数字以外的任何字符时，IDValidation函数将返回false。我还打印了返回，所以你可以很容易地理解它是如何工作的。

import java.util.Scanner;

public class Daniel {
    private static Scanner sc;

    private static boolean idValidation(String id) {
        try {
            Integer.parseInt(id);
            System.out.println("return true");
            return true;
        } catch (NumberFormatException e) {
            System.out.println("return false");
            return false;
        }
    }

      private static void readMonth(Scanner keyboardIn)
        {
            boolean success = false;
            while(!success)
            {   
                try
                {
                    System.out.print("Enter the month the account opened: ");
                    String m = keyboardIn.nextLine();
                    if(!idValidation(m)){
                        return;
                    }
//                  dateOpened.setMonth(m);
                    success = true;
                }catch(Exception e)
                {
                    System.out.println(e.getMessage());
                }   
              } 
           }    


        // Enter the year, checking for errors
        private static void readYear(Scanner keyboardIn)
        {
            boolean success = false;
            while(!success)
            {   
                try
                {
                    System.out.print("Enter the year the account opened: ");
                    String y = keyboardIn.nextLine();
                    if(!idValidation(y)){
                        return;
                    }

//                  dateOpened.setYear(y);
                    success = true;
                }catch(Exception e)
                {
                    System.out.println(e.getMessage());
                }
            }
        }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        readMonth(sc);
        readYear(sc);
    }
}