Code Recipes Blog

In this post under Passay, I will show with example how to verify whether a user entered password is within the configured length.

Below is the complete main code for your reference.

Main code

1  package defaultPackage;
2  
3  import java.util.Scanner;
4  
5  import org.passay.LengthRule;
6  import org.passay.PasswordData;
7  import org.passay.PasswordValidator;
8  import org.passay.Rule;
9  import org.passay.RuleResult;
10 
11 public class Example1 {
12     public static void main(String[] args) {
13         Rule lengthRule = new LengthRule(8, 16);
14         PasswordValidator passwordValidator = new PasswordValidator(lengthRule);
15         Scanner scanner = new Scanner(System.in);
16         System.out.println("First test");
17         System.out.println("Enter password");
18         String data = scanner.next();
19         PasswordData passwordData = new PasswordData(data);
20         RuleResult ruleResult = passwordValidator.validate(passwordData);
21         System.out.println("Result of password validation: " + ruleResult.isValid());
22         System.out.println("--------------------------------------");
23         
24         System.out.println("Second test");
25         System.out.println("Enter password");
26         data = scanner.next();
27         passwordData = new PasswordData(data);
28         ruleResult = passwordValidator.validate(passwordData);
29         System.out.println("Result of password validation: " + ruleResult.isValid());
30         System.out.println("--------------------------------------");
31         
32         System.out.println("Third test");
33         System.out.println("Enter password");
34         data = scanner.next();
35         passwordData = new PasswordData(data);
36         ruleResult = passwordValidator.validate(passwordData);
37         System.out.println("Result of password validation: " + ruleResult.isValid());
38     }
39 }

In the above code, at line 13 I create a rule which says the length of the password should between 8 and 16. So minimum length should 8 and maximum length should 16.

Anything less than 8 is invalid and anything more than 16 is invalid. Whereas within 8 and 16 is a valid password.

To create this rule, I take help of “Rule” inteface and one of its implementations called “LengthRule”. Both are provided by Passay framework for use.

At line line 14, I create an instance of “PasswordValidator” class and pass the rule as an constructor argument.

This will create a “PasswordValidator” instance by name “passwordValidator” which will validate the length rule.

Next I perform the first test (refer line 16 to 22), in which I take user input and assign it to “data” String variable. Refer to line 18.

At line 19, I create an instance “PasswordData” class and pass the String input (i.e., data variable) as a constructor argument.

This “PasswordData” class will have password related information. It will be used by rules to perform validation.

At line 20, I call “validate” method available on “passwordValidator” instance and pass “PasswordData” instance as an argument.

The “validate” method return an instance “RuleResult” which will contain test results.

At line 21, I check whether user entered password is valid or not by calling “isValid” method on “RuleResult” instance.

In this way we can validate whether a password is within the given length.

Below is the output for your reference

Output

First test
Enter password
hello
Result of password validation: false
--------------------------------------
Second test
Enter password
hellohello
Result of password validation: true
--------------------------------------
Third test
Enter password
hellohellohellohello
Result of password validation: false