lengthcomplexityrule helps in defining the applicable rule on a password based on its length. consider the following policy.

• if length of password is in between 1 to 5 characters, only lower case alphabets are allowed.

• if length of password is in between 6 to 8 characters, then only a, b and c are allowed.

example

the below example shows the validation of a password against above policy using passay library.

import org.passay.allowedcharacterrule;
import org.passay.characterrule;
import org.passay.englishcharacterdata;
import org.passay.lengthcomplexityrule;
import org.passay.passworddata;
import org.passay.passwordvalidator;
import org.passay.ruleresult;

public class passayexample {
   public static void main(string[] args) {
      lengthcomplexityrule lengthcomplexityrule = new lengthcomplexityrule();
      //rule: password of 1 to 5 characters should contains lower case alphabets only
      lengthcomplexityrule.addrules("[1,5]", 
         new characterrule(englishcharacterdata.lowercase, 5));
      //8 and 16 characters
      lengthcomplexityrule.addrules("[6,8]", 
         new allowedcharacterrule(new char[] { 'a', 'b', 'c' }));    
      passwordvalidator validator = new passwordvalidator(lengthcomplexityrule);
      passworddata password = new passworddata("abcdef");
      ruleresult result = validator.validate(password);
      if(result.isvalid()){
         system.out.println("password validated.");
      }else{
         system.out.println("invalid password: " + validator.getmessages(result));            
      }
   }
}

output

invalid password: [
password contains the illegal character 'd'., 
password contains the illegal character 'e'., 
password contains the illegal character 'f'., 
password meets 0 complexity rules, but 1 are required.]