CMSC 150: Introduction to Computing Sections: 03, 04 Fall 2016

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Programming Assignment 10

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Due: Week of Nov. 14 in lab

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Using inheritance, write a basic social network. Your network will resemble some elements of Facebook. There should be an Account super class. Two types will extend Account, Person and Page. There should be a Relationship super class. Two types will extend Relationship, Friend and Follow. You should also have a client program for the social network that defines the main.

Name the files Account.java, Person.java, Page.java, Relationship.java, Friend.java, Follow.java, and SocialNetwork.java.

Other details:

• Account - at a minimum
  • Should have at a minimum a name.
  • Should provide an accessor for the name variable.
  • Should override the toString function appropriately.
• Person - at a minimum
  • Should have an array of at most 100 Friend (note, that Java arrays can store null).
  • Should have an array of at most 10 Follow.
  • The constructor does NOT take an array of Friend or an array of Follow
  • A function addFriend(Person p) will create a Friend relationship between two people. Essentially it will call a helper function of this and p that searches for an empty (null) location in the friend array to insert a new Friend object. If no such location exists, report failure.
  • A function like(Page p) will search the following array for an empty location to insert a new Follow object. This function should also increment the number of followers (through a function) of p. If no location exists, report failure.
  • Should override the toString function appropriately. This function should call Account's toString function to increase code reuse (through super). Ensure that you output a list of friends and a list of follows (one line per friend/follow).
  • It is recommended to keep track of the number of friends and the number of followers as well. It might make error checking and implementation easier.
• Page - at a minimum
  • Should have an int for the number of followers.
  • The constructor does NOT take an integer for the number of followers. It should start at 0.
  • Should hava a function to increase the number of followers.
  • Should override the toString function appropriately. This function should call Account's toString function to increase code reuse. Ensure that you output the number of followers.
• Relationship - at a minimum
  • Should have a Date for the creation of the relationship (lookup java.util.Date).
  • Should override the toString function appropriately.
• Friend - at a minimum
  • Should contain a reference of a Person (recall a reference is a pointer). this means the Friend object points to an existing Person object. Do not use new when sending a Person in the constructor.
  • Should override the toString function appropriately. this function should call Relationship's toString function to increase code reuse. Only output the name of the Person instead of calling toString.
• Follow - at a minimum
  • Should contain a reference of a Page. This means the Follow object points to an existing Page object. Do not use new when sending a Page in the constructor. Also increment the number of follows on that page here.
  • Should override the toString function appropriately. this function should call Relationship's toString function to increase code reuse. Only output the name of the Page instead of calling toString.
• SocialNetwork - at a minimum
  • Should create two Person objects and one Page object. Have both people befriend each other and also follow the page.

Example output of SocialNetwork's test:
Person
Account name: Jory Denny
Number of friends: 1
Number of follows: 1
Friends
Friend. Relationship created Mon Nov 14 10:15:13 EST 2016. With Zachary Pollock.
Follows
Follow. Relationship created Mon Nov 14 10:15:13 EST 2016. Following Zen-Do-Kai Karate.

Person
Account name: Zachary Pollock
Number of friends: 1
Number of follows: 1
Friends
Friend. Relationship created Mon Nov 14 10:15:13 EST 2016. With Jory Denny.
Follows
Follow. Relationship created Mon Nov 14 10:15:13 EST 2016. Following Zen-Do-Kai Karate.

Page
Account name: Zen-Do-Kai Karate
Number of followers: 2

Bonus. Provide an example of polymorphism in your product, either with relationships or accounts. Other extensions: provide a feed and post mechanism for accounts using Strings.

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Grading

Each assignment is graded out of 100% based on a combination of the criteria listed in the assignment description and programming style (e.g., good comments and naming) -- following instructions is extremely important in computer science, train yourself to think like the computer; programming style is important to be able to communicate your solutions to another programmer; both of which you are graded upon.

Specific instructions. Failure to do these steps will result in a loss of points.

• Name each file and program as listed in the instructions.
• Name all variables descriptively.
• Indent all programs appropriately.
• Use comments to help explain the steps and logic of your program.
• The top of your program should have a comment block where the first line is your name, second line is your section, and third line is a description of your java program.
  //Name: Jory Denny
//Section: 00
//This program debates Batman vs Superman!

Turn in instructions. Each programming assignment is to be turned in before your lab section. You will turn in a soft copy of the assignment (.java or .zip for multiple java files) through blackboard. You will also turn in a hard copy of the assignment in your lab section with a signed coverpage (each program should start a new page of the hard copy).

If there are any discrepencies in grades please see the instructor during his office hours or by appointment (do not discuss with the lab assistants or graders).

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