/**
* The MIT License
* Copyright (c) 2014-2016 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.dao;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import java.util.stream.Stream;
/**
* An in memory implementation of {@link CustomerDao}, which stores the customers in JVM memory
* and data is lost when the application exits.
* <br/>
* This implementation is useful as temporary database or for testing.
*/
public class InMemoryCustomerDao implements CustomerDao {
private Map<Integer, Customer> idToCustomer = new HashMap<>();
/**
* An eagerly evaluated stream of customers stored in memory.
*/
@Override
public Stream<Customer> getAll() {
return idToCustomer.values().stream();
}
@Override
public Optional<Customer> getById(final int id) {
return Optional.ofNullable(idToCustomer.get(id));
}
@Override
public boolean add(final Customer customer) {
if (getById(customer.getId()).isPresent()) {
return false;
}
idToCustomer.put(customer.getId(), customer);
return true;
}
@Override
public boolean update(final Customer customer) {
return idToCustomer.replace(customer.getId(), customer) != null;
}
@Override
public boolean delete(final Customer customer) {
return idToCustomer.remove(customer.getId()) != null;
}
}