Passay-AllowedRegexRule

Passay-AllowedRegexRule is a validation rule for the Passay library, which allows developers to check if a password meets certain requirements. In particular, it checks if a password matches a specified regular expression pattern. This rule can be useful for enforcing specific password complexity requirements.

To use Passay-AllowedRegexRule, you need to add the Passay library to your project's dependencies. Then, you can create a new instance of the rule and add it to the validator that you're using. Here's an example:

import org.passay.*;
import java.util.Arrays;

public class PasswordValidator {
    public static void main(String[] args) {
        String regex = "^[a-zA-Z0-9@#$%^&+=]{8,}$";
        PasswordValidator validator = new PasswordValidator(Arrays.asList(
            new LengthRule(8, 30),
            new AllowedRegexRule(regex)
        ));
        RuleResult result = validator.validate(new PasswordData("abc123!@#"));
        if (result.isValid()) {
            System.out.println("Password is valid");
        } else {
            String errorMsg = validator.getMessages(result).get(0);
            System.out.println("Password is invalid: " + errorMsg);
        }
    }
}

In this example, we're creating an instance of AllowedRegexRule with a regular expression that matches passwords that contain at least 8 characters, including letters, numbers, and certain special characters. We then add this rule to our PasswordValidator instance, along with a LengthRule that enforces a minimum and maximum password length.

We then validate a test password using the validate method of our PasswordValidator instance. If the password passes validation, we print a success message. Otherwise, we retrieve the error message using the getMessages method of our PasswordValidator instance, and print an error message.

Overall, Passay-AllowedRegexRule provides a powerful and flexible way to enforce password complexity requirements in your applications. By using regular expressions to specify password patterns, developers can create highly customized password rules without having to write lots of code.