Thread: some error

public class countletters { public static boolean letter(char L) { String letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; return (letters.indexOf(L) >= 0); }   public static boolean Space(char Sp) { String space = " "; return (space.indexOf(Sp) >= 0); }   public static void main(String[] args) { int letterNo, consNo, splNo, digitNo, passNo, i; String password;   System.out.println ("Enter password: "); password = Keyboard.readString();   passNo = 0; for(i = 0; i<password.length();i++){ passNo++; }   letterNo = 0; for (i=0;i<password.length();i++) { if (letter(password.charAt(i))) { letterNo ++;   } }   digitNo = 0; for (i=0;i<password.length();i++) { if (Character.isDigit(password.charAt(i))){ digitNo ++;   } }   splNo = 0; for (i=0;i<password.length();i++) { if (!Character.isLetter(password.charAt(i)) && !Space((password.charAt(i))) && !Character.isDigit(password.charAt(i))){ splNo ++;   } } while(passNo<6 && passNo >10 && letterNo>=1 && digitNo >=1 ){ System.out.println("Enter password: "); System.out.println("please enter a valid password:"); Keyboard.readString(); }     } }

hehe^^...I dont usually use while loops ...anything i can do to make this work?

Looking at the code in my IDE all I get is an error saying that it cant find the class Keyboard. What type of error are you getting or what exactly are you experiencing as wrong in this code?

I take it this is a way of checking to see if the input password is long and strong enough?

I've created a utility class for this before which can been seen below. This class will also generate a password for you of the given length.

/** * Password generator created for the members of Java Programming Forums. Feel free * to use this in your own applications. Please give credit where credit is due. * * @author Daniel Johansson * @since 9 Jul 2009 */ public class PasswordUtility {   private static final String ALPHA_CHARACTERS = "abcdefghijklmnopqrstuvwxyz";   private static final String DIGITS = "0123456789";   private static final String SYMBOLS = "$%&*@#!_:~";   /** * Since this is a utility class there is no need to instantiate it. All statics baby! */ protected PasswordUtility() { throw new UnsupportedOperationException(); }   /** * Generates a random password of the specified length using uppercase letters, lowercase letters, digits and symbols. * * @param length the length of the password. * @return character array representing the password */ public static char[] generate(final int length) { final String allowedCharaters = ALPHA_CHARACTERS + DIGITS + SYMBOLS; final Random random = new Random(); final char[] password = new char[length];   for (int i = 0; i < length; ++i) { password[i] = allowedCharaters.charAt(random.nextInt(allowedCharaters.length() - 1)); }   return password; }   /** * Calculates the strength of the password based on certain factors such as. * <ul> * <li>Length</li> * <li>Number of upper case letters</li> * <li>Number of lower case letters</li> * <li>Number of digits</li> * <li>Number of digits or symbols in the middle</li> * <li>Any repeating characters</li> * <li>Sequences</li> * * It also adds bonuses if the password is 8 characters or more and it has a certain combination of lowercase, * uppercase, digits and symbols. * * @param password the password to check the strength of * @return the strength which is a value between zero and one hundred (0 - 100). */ public static int strength(final String password) { int strength = 0;   // Length strength += (password.length() * 4);   // Upper case letters final int upperCase = matches(password, "[A-Z]");   if (upperCase > 0) { strength += ((password.length() - upperCase) * 2); }   // Lower case letters final int lowerCase = matches(password, "[a-z]");   if (lowerCase > 0) { strength += ((password.length() - lowerCase) * 2); }   // Numbers final int numbers = matches(password, "[0-9]");   if (numbers > 0) { strength += (numbers * 4); }   if (numbers == password.length()) { strength -= numbers; }   // Sepcial characters final int specialCharacters = matches(password, "[:,!,@,#,$,%,^,&,*,?,_,~]");   if (specialCharacters > 0) { strength += (specialCharacters * 6); }   // Letters only final int letters = matches(password, "[a-z|A-Z]");   if (letters == password.length()) { strength -= letters; }   // Middle numbers int middles = 0;   for (int j = 0; j < DIGITS.length(); ++j) { if ((password.indexOf(DIGITS.charAt(j)) > 0) && (password.indexOf(DIGITS.charAt(j)) < password.length() - 1)) { ++middles; } }   // Middle symbols for (int j = 0; j < SYMBOLS.length(); ++j) { if ((password.indexOf(SYMBOLS.charAt(j)) > 0) && (password.indexOf(SYMBOLS.charAt(j)) < password.length())) { ++middles; } }   strength += (middles * 2);   // Repeat charaters final List<Character> done = new ArrayList<Character>(); int repeats = 0;   for (int i = 0; i < password.length(); ++i) { int matches = 0;   for (int j = 0; j < password.length(); ++j) { if (password.toLowerCase().charAt(i) == password.toLowerCase().charAt(j) && !done.contains(password.toLowerCase().charAt(i))) { ++matches; } }   if (matches > 1) { strength -= (matches * (matches - 1)); repeats += (matches * (matches - 1)); done.add(password.toLowerCase().charAt(i)); } }   // Consequtive upper case letters final int consequtiveUpperCaseLetters = matches(password, "[A-Z]{2}"); strength -= (consequtiveUpperCaseLetters * 2);   // Consequtive lower case letters final int consequtiveLowerCaseLetters = matches(password, "[a-z]{2}"); strength -= (consequtiveLowerCaseLetters * 2);   // Consequtive numbers final int consequtiveNumbers = matches(password, "[0-9]{2}"); strength -= (consequtiveNumbers * 2);   // Sequential characters for (int i = 0; i < password.length(); ++i) { final int index = ALPHA_CHARACTERS.indexOf(String.valueOf(password.charAt(i)).toLowerCase());   if (index != -1 && index < ALPHA_CHARACTERS.length() - 3) { final String forwardSequence = ALPHA_CHARACTERS.substring(index, index + 3); final String reverseSequence = new StringBuffer(forwardSequence).reverse().toString();   if (password.indexOf(forwardSequence) != -1 || password.indexOf(reverseSequence) != -1) { strength -= 3; } } }   // Sequential numbers for (int i = 0; i < password.length(); ++i) { final int index = DIGITS.indexOf(String.valueOf(password.charAt(i)).toLowerCase());   if (index != -1 && index < DIGITS.length() - 3) { final String forwardSequence = DIGITS.substring(index, index + 3); final String reverseSequence = new StringBuffer(forwardSequence).reverse().toString();   if (password.indexOf(forwardSequence) != -1 || password.indexOf(reverseSequence) != -1) { strength -= 3; } } }   // Bonuses int bonus = 0;   if (password.length() >= 8) { ++bonus;   if (((double) upperCase / (double) password.length()) >= 0.25) { ++bonus; }   if (((double) lowerCase / (double) password.length()) >= 0.25) { ++bonus; }   if (((double) numbers / (double) password.length()) >= 0.25) { ++bonus; } if (((double) specialCharacters / (double) password.length()) >= 0.25) { ++bonus; } }   strength += (bonus * 2);   if (strength < 0) { strength = 0; } else if (strength > 100) { strength = 100; }   return strength; }   private static int matches(final String string, final String regexPattern) { int matches = 0; final Pattern pattern = Pattern.compile(regexPattern); final Matcher matcher = pattern.matcher(string);   while (matcher.find()) { ++matches; }   return matches; } }

Enjoy!

// Json