Bank, BankUtils class

package BankPkg;

import java.time.LocalDate;
import java.time.temporal.ChronoUnit;
import java.util.Arrays;

public class BankUtils {
    public static final int minClientAge = 16;
    public static final int minNameLength = 2;
    public static final int minId = 100000000;
    public static final int maxId = 999999999;

    public static final double minLoanFee = 0.01;
    public static final double maxLoanFee = 0.10;

    protected static double loanFee = 0.02;

    public static double getLoanfee() {
        return BankUtils.loanFee;
    }

    protected static boolean setLoanFee(double loanFee) {
        if (BankUtils.isBetween(loanFee, minLoanFee, maxLoanFee)) {
            BankUtils.loanFee = loanFee;
            return true;
        }

        return false;
    }

    public static boolean isValidId(int id) {
        return (id >= BankUtils.minId && id <= BankUtils.maxId);

    }

    public static boolean isValidName(String name) {

        String[] words = name.split(" ");
        for (String item : words) {
            // every word is letters only and has enough chars
            if (!item.matches("[a-zA-Z]{" + BankUtils.minNameLength + ",}")) {
                return false;
            }
        }
        return true;
    }

    public static LocalDate dublicate(LocalDate date) {
        return date.plusDays(0);
    }

    public static long getAge(LocalDate birthDate) {
        return ChronoUnit.YEARS.between(birthDate, LocalDate.now());
    }

    public static long getAge(LocalDate birthDate, LocalDate atDate) {
        return ChronoUnit.YEARS.between(birthDate, atDate);
    }

    public static boolean isBetween(double num, double min, double max) {
        return (num >= min && num <= max);
    }

    public static Object[] addToArray(Object[] array, Object obj) {
        Object[] result = Arrays.copyOf(array, array.length + 1);
        result[result.length - 1] = obj;

        return result;
    }

    public static int[] addToArray(int[] array, int num) {
        int[] result = Arrays.copyOf(array, array.length + 1);
        result[result.length - 1] = num;

        return result;
    }

}