Week 5

Question 1

How does the Factory Design Pattern separate responsibility/details for creating an instance?

Answer 1

It separates the responsibility/details for creating an instance from the class that uses the instance.

Question 2

The factory design pattern uses 2 interfaces/abstract classes. How do they work?

Answer 2

One is used to create the object, the other is used to interact with the object.

Question 3

What Java class have we used recently that utilizes the Factory pattern?

Answer 3

DriverManager.

Question 4

Explain how DriverManager works as a factory

Answer 4

DriverManager can create instances of connections to DBs.

Question 5

DriverManager manages a list of ‘drivers’ registered. What iterates through the registered driver to crreate and return the connection to the caller?

Answer 5

getConnection()

Question 6

T/F - You can have multiple drivers per type of DB

Answer 6

False. 1 per DB (MySQL, Oracle)

Question 7

Files.____________() uses the factory design pattern to create an inputStream object to read a files content.

Answer 7

Files.newInputStream()

Question 8

How does Abstract Factory Design differ from Simple Factory Design? What advantage does it offer?

Answer 8

Abstract can create different but related objects, like several different types of calculators.

Other than that it also abstracts further.

Question 9

Factory and Builder are both creational DPs that encapsulate internal representation and construction steps.

How do Factory and Builder differ?

Answer 9

Factory can create an object in a single method call (often static). Can be thought of as a wrapper for a constructor.

Builder creates objects using multiple method calls,often using chaining

Builder permits optional features and/or deaults