Password requirement

Question

Websites commonly require a password that satisfies several requirements. Write a program that checks if an input string satisfies the following (error message is shown for each):

1. At least 8 characters (Too short)
2. At least one letter (Missing letter)
3. At least one number (Missing number)
4. At least one of these special characters: !, #, % (Missing special)

Output OK, or all related error messages (in above order). If the input string is "Hello", the output is:

Too short

Missing number

Missing special

Hints:

1. Declare a boolean variable for each requirement.
2. Use a for loop to visit each character, setting the corresponding boolean to true if satisfied (length is done differently though).
3. Use the functions Character.isLetter() and Character.isDigit() to detect if a character is a letter or a number.

import java.util.Scanner;

public class Main {

public static void main(String[] args) {

Scanner scnr = new Scanner(System.in);

/* Type your code here. */

}

}

Answer 1

import java.util.Scanner;

class PasswordValidator

{

private Scanner scanner;

public static final int PASSWORD_OK=0;

public static final int PASSWORD_TOO_SHORT=8;

public static final int PASSWORD_NO_ALPHA=4;

public static final int PASSWORD_NO_DIGIT=2;

public static final int PASSWORD_NO_SPECIAL_CHAR=1;

PasswordValidator()

{

scanner = new Scanner(System.in);

}

public int Validate(String password)

{

int iReturn = this.PASSWORD_OK;

int iLengthPW = password.length();

if (iLengthPW<8) { iReturn -= this.PASSWORD_TOO_SHORT; }

boolean alphaFlag=false;

boolean digitFlag=false;

boolean specialCharFlag=false;

for (int iLoop=0; iLoop<iLengthPW; iLoop++)

{

char chChar = password.charAt(iLoop);

Character curChChar = new Character(chChar);

if (curChChar.isLetter(chChar)) { alphaFlag=true; }

if (curChChar.isDigit(chChar)) { digitFlag = true; }

if ((chChar=='!') || (chChar=='#') || (chChar=='%')) { specialCharFlag=true; }

if (alphaFlag && digitFlag && specialCharFlag) { break; }

}

if (!alphaFlag) { iReturn -= this.PASSWORD_NO_ALPHA; }

if (!digitFlag) { iReturn -= this.PASSWORD_NO_DIGIT; }

if (!specialCharFlag) { iReturn -= this.PASSWORD_NO_SPECIAL_CHAR; }

return(iReturn);

}

public void Go()

{

System.out.print(" Please input the password :>");

String pw = scanner.next();

int iReturn = this.Validate(pw);

if (iReturn<0)

{

iReturn = -iReturn;

if ((iReturn/this.PASSWORD_TOO_SHORT)==1)

{

System.out.println(" Password Too Short: 8 characters min ");

}

iReturn %= this.PASSWORD_TOO_SHORT;

if ((iReturn/this.PASSWORD_NO_ALPHA)==1)

{

System.out.println(" Missing letter: at least one alphabetic character required ");

}

iReturn %= this.PASSWORD_NO_ALPHA;

if ((iReturn/this.PASSWORD_NO_DIGIT)==1)

{

System.out.println(" Missing number: at least one digit is required ");

}

iReturn %= this.PASSWORD_NO_DIGIT;

if (iReturn==1)

{

System.out.println(" Missing special character: at least one of ! # % is required ");

}

}

else

{

System.out.println(" Password OK ");

}

}

public static void main(String args[])

{

PasswordValidator x = new PasswordValidator();

x.Go();

}

}