Java Como Programar Deitel 11 Pdf | Fast

// Violation: High-level class depends directly on low-level class
class EmailNotifier 
    public void send(String message)  /* send email */
class OrderService 
private EmailNotifier notifier = new EmailNotifier(); // concrete dependency
public void placeOrder()  notifier.send("Order placed"); 

// Compliance: Depend on abstraction
interface Notifier 
void send(String message);

class EmailNotifier implements Notifier  ... 
class SMSNotifier implements Notifier  ... 
class OrderService 
private Notifier notifier; // depends on abstraction
public OrderService(Notifier notifier)  this.notifier = notifier;  // dependency injection
public void placeOrder()  notifier.send("Order placed");
 java como programar deitel 11 pdf

Se o valor do livro novo (entre R$ 300 e R$ 500) está fora do orçamento, considere:

Use interfaces to define roles:

interface Flyable  void fly(); 
interface Walkable  void walk();
class Sparrow implements Flyable, Walkable  ... 
class Penguin implements Walkable  ... 

If budget is a concern, here are excellent free resources: // Violation: High-level class depends directly on low-level

Software entities should be open for extension but closed for modification.