Object Oriented Development Assignment 1

1. Objective: a. To expose students to the Observer design pattern. b. To sharpen students’ design skills in improving the Observer pattern to accept multiple Subjects. 2. List of software NetBeans or NotePad++ with an installed JDK 3. Report and Marks For each questions in this assignment, your report must include the following: a. A UML class-diagram of your solution 40% b. Source code of solution 40% 20 % will be given for a successful demonstration of your solution. Due marks will be given for good coding styles (indents, capitalization, variable / method / class names, etc.). Submit both a hardcopy and softcopy of your report. This assignment is worth 10% of the overall marks for the course. 4. Due date Part 5(a): 30/09/2014 (Tuesday), 5pm Part 5(b): 02/10/2014 (Thursday), 5pm 5. Questions Answer the following two questions. Mark distribution is as indicated at the end of each question. a. Modify the ObserverExample source code to handle any number of Subject objects per Observer. Use the following code for main(String[] args) : public static void main(String[] args) { PairOfNumbers numbers1=new PairOfNumbers(); PairOfNumbers numbers2=new PairOfNumbers(); SumObserver sum=new SumObserver(numbers1); ProductObserver prod=new ProductObserver(numbers2); MultiSubjectObserver m=new MultiSubjectObserver(); [login to view URL](numbers1); [login to view URL](numbers2); [login to view URL](20, 10); [login to view URL](-10, 15); } Sample output: New sum is: 30.0 MultiSubjectObserver activated with numbers: 20.0, 10.0 New product is: -150.0 MultiSubjectObserver activated with numbers: -10.0, 15.0 You are not allowed to change the following classes from the ObserverExample source code: Observer, Subject, PairOfNumbers, SumObserver, and ProductObserver. (60 marks) b. Based on the solution of 5(a), implement a WeatherObserver that would be able to track a TemperatureSensor, a PressureSensor, and a HumiditySensor. Use the following code for main(String[] args) : public static void main(String[] args) { TemperatureSensor t = new TemperatureSensor(); PressureSensor p = new PressureSensor(); HumiditySensor h = new HumiditySensor(); WeatherObserver w = new WeatherObserver(); [login to view URL](t); [login to view URL](p); [login to view URL](h); [login to view URL](28); [login to view URL]("-------------------------------"); [login to view URL](200); [login to view URL]("-------------------------------"); [login to view URL](89); } Sample output: Temperature : 28 Celcius Pressure : 0 Pascal Humidity : 0 % ------------------------------- Temperature : 28 Celcius Pressure : 200 Pascal Humidity : 0 % ------------------------------- Temperature : 28 Celcius Pressure : 200 Pascal Humidity : 89 % You are not allowed to change the following classes from 5(a): Observer and Subject. (40 marks)