CSE 1030: Aggregation and Composition

1. CSE 1030: Aggregation and Composition Mark Shtern

2. Summary • Aggregation • Constructors • Accessor/Mutators • Collections

3. Collections • Copy Contractor • Alias this.setBooks(library.books) • Shallow Copy this.setBooks(new ArrayList(library.getBooks())) • Deep Copy ArrayList copy= new ArrayList(); for (Book book:books) copy.add(new Book(book)); this.setBooks(copy);

4. What is Composition • Object Composition is a way to combine simple object into more complex ones • Composite objects are usually expressed by means of references from one object to another • Exactly like Aggregation except that the lifetime of the 'part' is controlled by the 'whole'

5. Is it composition? Carburetor carburetor = new Carburetor(); car = new Car(carburetor); Answer: NO

6. Is it composition? Carburetor carburetor = new Carburetor(); car = new Car(carburetor); Answer:Yes

7. Is it possible? Carburetor carburetor = new Carburetor(); car = new Car(carburetor); Carburetor carburetor1 = carburetor; carburetor = car.getCarburetor(); Answer: NO

8. Is composition correctly implemented? Carburetor carburetor = new Carburetor(); car = new Car(carburetor); carburetor = car.getCarburetor(); Answer: When carburetor is immutable object then yes, otherwise no

9. Is composition correctly implemented? Carburetor carburetor = new Carburetor(); car = new Car(carburetor); carburetor = car.getCarburetor(); Answer:Yes

10. UML Diagram public Car { private Carburetor carburetor; Car () { carburetor = new Carburetor(); } }

11. Constructor Carburetor carburetor = new Carburetor(); car = new Car(carburetor); public Car(Carburetor carburetor) { this.setCarburator(carburetor); }

12. Method section • Accessor public Carburetor getCarburetor() { return new Carburetor (this.carburator); }

13. Method section • Mutator public boolean setCarburetor(Carburetor c) { // validation section // returns false if input is invalid this.carburator = new Carburetor(c); return true; }

14. Implementing Inheritance

15. Ex601 • Develop an directory application which stores personal information about students, faculty and staff. In addition to the information commonly found in telephone books, your directory contains the following data • Student  Major • Staff and Faculty  Room • Faculty Office hours • Staff Title

16. Design