package com.baeldung.dip.services; import com.baeldung.dip.daos.CustomerDao; import com.baeldung.dip.entities.Customer; import java.util.Map; import java.util.Optional; public class CustomerService { private final CustomerDao customerDao; public CustomerService(CustomerDao customerDao) { this.customerDao = customerDao; } public Optional findById(int id) { return customerDao.findById(id); } public List findAll() { return customerDao.findAll(); } }