java_json_xml_projekt1/src/main/java/company/PeselValidator.java

package company;

public class PeselValidator {

    public static boolean validate(String pesel) {
        if (pesel == null || pesel.length() != 11)
            return false;

        return validateControlSum(pesel);
    }

    private static boolean validateControlSum(String pesel) {
        int controlSum = 0;
        var weightings = new int[] { 1, 3, 7, 9, 1, 3, 7, 9, 1, 3 };
        var peselArray = pesel.toCharArray();

        for (int i = 0; i < 10; i++)
        {
            controlSum += Character.getNumericValue(peselArray[i]) * weightings[i];
        }

        controlSum = controlSum % 10;
        controlSum = 10 - controlSum;
        controlSum = controlSum % 10;

        if (controlSum == Character.getNumericValue(peselArray[10]))
            return true;

        return false;
    }
}