Strong passwords are at least 8 characters in length contain

Strong passwords are at least 8 characters in length, contain both upper- and lower-case letters, as well as some digits and special characters. Use the requirements (specified below) for a password to define in BNF a grammar for <strong password>

A valid password must contain the following elements:

- Standard U.S. keyboard characters only (such as the letters A through Z, the numbers 0 through 9, or the special characters on the top row of the keyboard)

- A minimum of 8 characters

- A maximum of 32 characters

- At least 1 number

- At least 1 of these special characters: ! $ & * < >

Solution

package com.chegg.strongpassword;

import java.util.Scanner;

public class StrongPasswordChecker {

  
  
   public static boolean isSpecialCharacter(Character c)
   {
       return c.toString().matches(\"[^a-z A-Z0-9]\");
   }
   /*
   * This method is used to valid password given by user whether method
   * contains character,letter(lower and upper), numeric value and special character if contains return true or
   * false
   *
   * @param password
   *
   * @return boolean
   */
   public static boolean isValid(String password) {
       int length = password.length();
       boolean lower = false;
       boolean upper = false;
       boolean number = false;
       boolean special = false;
      

       // check condition if character length 6-10
       if ((length >= 8) && (length <= 32)) {
           {
               for (int i = 0; i < length; i++) {
                   // check condition if password contains digit or not
                   if (Character.isDigit(password.charAt(i))) {
                       number = true;
                   }
                  
                   // check condition if password contains lower case letter or not
                   if (Character.isLowerCase(password.charAt(i))) {
                       lower = true;
                   }
                  
                   // check condition if password contains upper case letter or not
                   if (Character.isUpperCase(password.charAt(i))) {
                       upper = true;
                   }
                  
                   // check condition if password contains special or not
                   if(StrongPasswordChecker.isSpecialCharacter(password.charAt(i))){
                       special = true;
                   }
                  
               }

           }
       } else {
           System.out.println(\"condition failed!\");
       }
       return (number && lower && upper && special);

   }

   public static void main(String[] args) {
       Scanner scan = new Scanner(System.in);
       System.out.println(\"Please enter a given password : \");
       String password = scan.nextLine();
       System.out.println(isValid(password));
       if (isValid(password)) {
           System.out.println(\"Welcome password is correct\");
       } else {
           System.out.println(\"Invalid Passowrd. Password, \" + \"must contain atleast 1 lower case, \"
                   + \"must contain atleast 1 upper case, \" + \"must contain atleast 1 special character, \"
                   + \" 1 digit, 1\" + \" and \" + \"characters between 8-32 long\");
       }
       scan.close();
   }
}