/**

* Day 38 - Spring Data JPA: Repository and Service

*/

import java.util.*;

class Order {

int id;

String customerName;

double totalAmount;

Order(int id, String customerName, double totalAmount) {

this.id = id;

this.customerName = customerName;

this.totalAmount = totalAmount;

}

}

class OrderRepository {

List<Order> orders = new ArrayList<>();

void save(Order order) { orders.add(order); }

Optional<Order> findById(int id) {

return orders.stream().filter(o -> o.id == id).findFirst();

}

List<Order> findAll() { return new ArrayList<>(orders); }

}

class OrderService {

OrderRepository repo = new OrderRepository();

void createOrder(Order order) { repo.save(order); }

Optional<Order> getOrder(int id) { return repo.findById(id); }

List<Order> getAllOrders() { return repo.findAll(); }

}

public class JPARepositoryExample {

public static void main(String[] args) {

OrderService service = new OrderService();

service.createOrder(new Order(1, "John", 150.00));

service.createOrder(new Order(2, "Jane", 250.00));

System.out.println("All Orders:");

service.getAllOrders().forEach(o ->

System.out.println(" Order " + o.id + ": " + o.customerName + " - $" + o.totalAmount)

);

}

}