Java-如何在日期输入中仅接受整数？

Question

Hey guys so my project for checking a user's input of a date in the format of mm/dd/yyyy works, but now I need to modify it so that it rejects anything not numbers. For example if I input 12/5/abcd or aa/12/2014 it should return me an error. At the moment if I enter a char or letters into the program it'll give an error saying something like "you should enter only valid integers". I'm using a delimiter for "/" to separate months and days and \\r or enter/return at the end of the year to finish the user input.

Answer 1

Only integer check won't work (consider someone enters 30-02-2013

you need to validate Date specifically, You should use SimpleDateFormat with setLenient(false)

Answer 2

Simply put an if condition to check the instance of integer on dd, mm and yy. Like

if(x instanceof Integer){
         ...
}

Answer 3

我认为，使用Java正则表达式使用以下正则表达式来验证输入日期。

([0-9]{2})\\\\([0-9]{2})\\\\([0-9]{4})

Answer 4

If you only care about digits vs non-digits, you can validate with a simple regular expression.

import java.util.regex.*;


public class A{
    public static void main(String[] args) {
        String original =  "12/24/1014";
        Pattern mypattern = Pattern.compile("\\d{2}/\\d{2}/\\d{4}");
        System.out.println(mypattern.matcher(original).matches());
        // If not true, throw error.
    }
}

Answer 5

you can use below date.

SimpleDateFormat sdf = new SimpleDateFormat("mm/dd/yyyy");

    boolean isValidDate(string input) {
         try {
              format.parse(input);
              return true;
         }
         catch(ParseException e){
              return false;
         }
    }