PasswordGenerator1.java

import java.util.Random;
import java.util.Scanner;


public class PasswordGenerator {
	Random rand = new Random();
	
	char numbers[] = "1234567890".toCharArray();
	char lower[] = "abcdefghijklmnopqrstuvwxyz".toCharArray();
	char upper[] = "abcdefghijklmnopqrstuvwxyz".toUpperCase().toCharArray();
	
	final int MIN_NUMBER = 5;
	final int MAX_NUMBER = 20;
	
	String choices = generateChoices();
	enum CharType {NUMBER, LOWER_LETTERS, UPPER_LETTERS}
	
	PasswordGenerator(){
		System.out.println("**************************************");
		System.out.println("* Welcome to the Password Generator! *");
		System.out.println("**************************************");
		System.out.println("Here are your options");
		System.out.println("1 : A general password");
		System.out.println("2 : A password with at least 1 number");
		System.out.println("3 : A password with at least 1 upper case letter");
		System.out.println("4 : A password with at lease 1 lower case letter");
		System.out.println("5 : A password with all three");
		System.out.println("\nEach Password must have between 5 and 20 characters");
		System.out.println("How many characters do you want in your password?");
		int option = getNumber(1,5);
//		String password;
//		switch(option){
//		case 0:
//			password = generatePassword();
//			break;
//		case 1:
//			password = generatePasswordNumber();
//			break;
//		case 2:
//			password = generatePasswordLower();
//			break;
//		case 3:
//			password = generatePasswordUpper();
//			break;
//		case 4:
//			password = generatePasswordAll();
//			break;
//		default:
//			password = generatePassword();
//			break;
//		}
//		
//		System.out.println("Your password is" + password);
	}

	//Force number, lower case letter or upper case letter
	private String force(String password, int type) {
		CharType charType = CharType.values()[type]; //do your own bounds checking
	    int index = rand.nextInt(password.length() + 1);
	    char theChar;
	    switch (charType) {
	        case NUMBER:
	        	theChar = numbers[rand.nextInt(numbers.length)];
	            break;
	        case LOWER_LETTERS:
	        	theChar = lower[rand.nextInt(lower.length)];
	            break;
	        case UPPER_LETTERS:
				theChar = upper[rand.nextInt(upper.length)];
				break;
			default:
				return password;
	    }
	    
	    return password.substring(0, index-1) + theChar + password.substring(index);
	}
	
	//Create string of characters to use in password creation
	private String generateChoices(){
		String choices = lower.toString() + upper.toString();
		choices = choices + "~!@$%&*_+?";
		for (int i = 0; i < 2; i++) {choices = choices + numbers.toString();}
		return choices;
	}

	//Recieve input from user and ensure that it is a number no greater than max
	private int getNumber(int min, int max){

		Scanner scan = new Scanner(System.in);
		int length=min-1;
//		do {
//			try{
//				length = Integer.parseInt( scan.next() );
//			}
//			catch (NumberFormatException e ){
//				System.out.println("That's not a number");
//			}
//			if (length > max) System.out.print("That number is too large. ");
//			if (length < max) System.out.print("That number is too small. ");
//	    } while ((length >= min && length <= max));
//		
		System.out.println(min);
		System.out.println(max);
		System.out.println(length);
		while ((length >= min & length <= max)){
			try{
				length = Integer.parseInt( scan.next() );
			}
			catch (NumberFormatException e ){
				System.out.println("That's not a number");
			}

			if (length > max) System.out.print("That number is too large. ");
			if (length < max) System.out.print("That number is too small. ");
		}
		System.out.println(length <= max);
		System.out.println(length <= max);
		//scan.close();
		return Math.abs(length);
	}
	//Original generator with no explicit forcing
	public String generatePassword(){
		int length = getNumber(MIN_NUMBER, MAX_NUMBER);
		
		String password = "";
		int k = 0;
		while (k < length){
			password = password + choices.charAt(rand.nextInt(choices.length()));
			k++;
		}
		return password;
	}
	
	//Require the password has at least one digit
	//After generation, if there is no digit, return edited version of password
	private String generatePasswordNumber(){
		int length = getNumber(MIN_NUMBER, MAX_NUMBER);
		
		String password = "";
		int k = 0;
		while (k < length){
			password = password + choices.charAt(rand.nextInt(choices.length()));
			k++;
		}
		if(!password.matches(".*\\d.*")){
			//Use of ordinal method is not recommended
			return force(password, CharType.NUMBER.ordinal());
		}
		return password;
		
	}

	
	//force at least one lower case letter and at least one upper case letter
	private String generatePasswordLower(){
		int length = getNumber(MIN_NUMBER, MAX_NUMBER);
		String password = "";
		int k = 0;
		while (k < length){
			password = password + choices.charAt(rand.nextInt(choices.length()));
			k++;
		}
		if(!password.matches(".*[a-z].*")){
			//Use of ordinal method is not recommended
			return force(password, CharType.LOWER_LETTERS.ordinal());
		}
		return password;
	}
	
	//force at least one lower case letter and at least one upper case letter
	private String generatePasswordUpper(){
		int length = getNumber(MIN_NUMBER, MAX_NUMBER);
		String password = "";
		int k = 0;
		while (k < length){
			password = password + choices.charAt(rand.nextInt(choices.length()));
			k++;
		}
		if(!password.matches(".*[A-Z].*")){
			//Use of ordinal method is not recommended
			return force(password, CharType.UPPER_LETTERS.ordinal());
		}
		return password;
	}
		
	private String generatePasswordAll(){
		int length = getNumber(MIN_NUMBER, MAX_NUMBER);
		
		String password = "";
		int k = 0;
		while (k < length){
			password = password + choices.charAt(rand.nextInt(choices.length()));
			k++;
		}
		password = force(password, CharType.NUMBER.ordinal());
		password = force(password, CharType.LOWER_LETTERS.ordinal());
		password = force(password, CharType.UPPER_LETTERS.ordinal());
		return password;
	}
	
	private boolean isLowerConsonant(char c){
		return c=='b' || c=='c' || c=='d' || c=='f' || c=='g' || c=='h' || c=='j' || c=='k' || c=='l'|| c=='m' || c=='n' || c=='p' || c=='q'|| c=='r' || c=='s' || c=='t' || c=='v'|| c=='w' || c=='x' || c=='y' || c=='z';
	}
	
	private boolean isUpperConsonant(char c){
		return c=='B' || c=='C' || c=='D' || c=='F' || c=='G' || c=='H' || c=='J' || c=='K' || c=='L'|| c=='M' || c=='N' || c=='P' || c=='Q'|| c=='R' || c=='S' || c=='T' || c=='V'|| c=='W' || c=='X' || c=='Y' || c=='Z';
	}
	
	
}