Decorator pattern demonstration

Employee.java

// Only a data class. DO NOT ADD BEHAVIORS
public class Employee {

    public Instant dateOfBirth;
    public BigDecimal salary;
    public float yearsInService;
}

ProfileController.java

public class ProfileController {

    private void someFoo(ProfileEmployee employee) {
        int age = employee.getAge();
        boolean isNewHire = employee.isNewHire();
    }

    private static class ProfileEmployee {

        private Employee employee;

        public ProfileEmployee(Employee employee) {
            this.employee = employee;
        }

        public int getAge() {
            return (int) ChronoUnit.YEARS.between(Instant.now(), employee.dateOfBirth);
        }

        public boolean isNewHire() {
            return employee.yearsInService < 0.5;
        }
    }
}

SalaryController.java

public class SalaryController {

    private static final BigDecimal loyaltyBonusMaxSalary = new BigDecimal("12345"); // arbitrary value

    private void someFoo(SalaryEmployee employee) {
        boolean eligibleForLoyaltyBonus = employee.isEligibleForLoyaltyBonus();
        double taxRate = employee.getTaxRate();
    }

    private static class SalaryEmployee {

        private final Employee employee;

        public SalaryEmployee(Employee employee) {
            this.employee = employee;
        }

        public boolean isEligibleForLoyaltyBonus() {
            return (employee.salary.compareTo(loyaltyBonusMaxSalary) < 0) &&
                    employee.yearsInService > 3;
        }

        public double getTaxRate() {
            // imagine some algorithm to calculate the employees tax rate
            return 0;
        }
    }
}