import java.io.FileNotFoundException;
import java.io.IOException;

import org.passay.CharacterCharacteristicsRule;
import org.passay.CharacterRule;
import org.passay.EnglishCharacterData;
import org.passay.LengthRule;
import org.passay.PasswordData;
import org.passay.PasswordValidator;
import org.passay.Rule;
import org.passay.RuleResult;
import org.passay.WhitespaceRule;

public class PassayExample {
   public static void main(String[] args) throws FileNotFoundException, IOException {
      //Rule 1: Password length should be in between 
      //8 and 16 characters
      Rule rule1 = new LengthRule(8, 16);        
      //Rule 2: No whitespace allowed
      Rule rule2 = new WhitespaceRule();        
      CharacterCharacteristicsRule rule3 = new CharacterCharacteristicsRule();        
      //M - Mandatory characters count
      rule3.setNumberOfCharacteristics(3);        
      //Rule 3.a: One Upper-case character
      rule3.getRules().add(new CharacterRule(EnglishCharacterData.UpperCase, 1));        
      //Rule 3.b: One Lower-case character
      rule3.getRules().add(new CharacterRule(EnglishCharacterData.LowerCase, 1));        
      //Rule 3.c: One digit
      rule3.getRules().add(new CharacterRule(EnglishCharacterData.Digit, 1));        
      //Rule 3.d: One special character
      rule3.getRules().add(new CharacterRule(EnglishCharacterData.Special, 1));

      PasswordValidator validator = new PasswordValidator(rule1, rule2, rule3);        
      PasswordData password = new PasswordData("microsoft@123");        
      RuleResult result = validator.validate(password);

      if(result.isValid()){
         System.out.println("Password validated.");
      } else {
         System.out.println("Invalid Password: " + validator.getMessages(result));            
      }
   }
}

Password validated.