I am making a password generator and I want the user to have the option to choose if they want to include upper/lower case letters, special chars and numbers but I am not sure how to do this with the code that I have right now without making too many if statements.

private static final String ALPHA_CAPS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
private static final String ALPHA = "abcdefghijklmnopqrstuvwxyz";
private static final String NUMERIC = "0123456789";
private static final String SPECIAL_CHARS = "!@#$%^&*_= -/";
private static SecureRandom random = new SecureRandom(); 

Above are the different chars that can be used to generate the password.

public void generatePasswordAgain(ActionEvent event) throws IOException {
    genPassword.setText(generatePassword(length, ALPHA_CAPS   ALPHA   SPECIAL_CHARS   NUMERIC));
}

Above is the function called when you want to generate a password. And below is the code that actually generates the password.

public static String generatePassword(int len, String dic) {
    String result = "";
    for (int i = 0; i < len; i  ) {
        int index = random.nextInt(dic.length());
        result  = dic.charAt(index);
    }
    return result;
}

I want to give the person using the program a chance to choose what type of chars they want to include in their program. Is there a way to do this without making too many if statements?

The persons demands for the chars they want to include are defined by booleans.

CodePudding user response：

If you want to avoid switch case and if else cascades, you may use a single line trinary operator.

private static final String EMPTY = "";

... // StringUtils.EMPTY can also be used.

boolean alphaUpper, alphaLower, numeric, special;

... // set your boolean flags here

genPassword.setText(generatePassword(length, (alphaUpper ? ALPHA_CAPS : EMPTY)   (alphaLower ? ALPHA : EMPTY)   (special ? SPECIAL_CHARS : EMPTY)   (numeric ? NUMERIC : EMPTY)));