Trying to master Regular expression :->

Hi, I want the input to accept only: digits, operators and space. How could I do?
I mean:

When I type: 8 – 9 a b c ! ?
It should throw exception.

When I type: 8 – 9 + 20 * 1 / 5
It should end in success.

I tried but could not :(

Code:

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package assignments;

import java.util.Scanner;

public class RegexTest {

        public static void main(String[] args) {

                Scanner scanner = new Scanner(System.in);
                String s = scanner.next();
               
                // try to input: 8 - 9 + 20 * 1 /  5               
                try {
                        if(s.matches("[^ \\d \\+ \\- \\* \\/]+"))
                                throw new Exception();
                } catch (Exception e) {                       
                        System.err.println("Recycle bin: \"I\'m here\"");
                }                                       
        }
}

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define an array and give operators which u want as value..get input and compare it array' s values..and use if for digits and space..

I'm sorry but I'd like to use regex. Read the topic tittle la. =__=
I think it's ok if I use regex in this case. (shorter and more professional I think)

Do it the other way round, instead of throwing the exception when the input matches that regex do it when the input does not match, but using this other regex (without the ^):

Code:

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[\\d\\+\\-\\*\\/ ]+

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