Computer Programming for
Coursework 3 Task Specification
Thomas Selig
Set: Monday, 6 May, 2024
This is the specification task sheet for the Coursework 3 assessment component of your CPT206
modul e.
This assignment has two parts: a coding part described in Section 1, and
a report described in Section 2. The submission deadline for this assignment is ,
2024, at 23:59 (China-time). Detailed submission instructions are provided in Section 3.
1 Program description (70 marks)
The aim of this coursework is to build a system which manages investments in companies’ shares. All
the work should be coded into a single Java NetBeans project, with the class structure and different
functionalities of the program described below. All classes should be properly encapsulated, as seen
in the Lectures and Labs throughout the semester. Your project should also contain a Controller
class for testing. You may leave some or all of your test code in the Controller class if you wish
when submitting, but no marks are allocated for this class’s contents in your submission. Instead
you will be asked to describe your testing in the report (see Section 2.3), and marked on that.
1.1 Market class (7 marks)
The Market class represents the current companies that are on the market, that is whose shares
can be traded (bought or sold). It therefore stores a collection of Company objects (see Section 1.2).
Any company can only appear on the market at most once. The class should also have methods
add() and remove() to add or remove a given company from the market, and contains() to check
if a given company is on the market or not. There will only be one market in the program, so all
members of the class should be static.
1.2 Company class (25 marks)
A Company object should store its (legal) name, a stability coefficient (a percentage between 0
and 100) indicating how stable its share prices are, and the history of its share prices. When a
Company object is created, its initial share price is specified (as well as the name and stability
coefficient). The history then consists of this initial share price. The Company class should have a
method getCurrentSharePrice() which returns the current share price of the company (this will
be the last share price in its history) and a method getInitialSharePrice() which returns the
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initial share price of the company (this will be the first share price in its history). There should
be methods to add or remove the company from the market, and to check if it is currently on the
market. There should be a method updateSharePrice() to update the valuation of a company’s
share price, according to the following formula:
Sharenew = Sharelast (1 + (1 − stab) ∗ U),
where:
• Sharenew is the new current share price of the property (after update);
• Sharelast is its old current share price (before update);
• stab is the company’s stability coefficient;
• U is a uniform random variable on the interval [−1, 1].
The new share price should then be added to the company’s history (as its last element).
Finally, there should be a method getTrend(int movementNumber, int significance) to
determine the trend of a company’s share value based on a number of recent movements. Given
two share prices in a company’s history s1 and s2, the movement is simply the difference s2 −s1. A
movement is consecutive if it is between two consecutive share prices in the company’s history. A
movement is considered significant if the ratio |s2−s1|
s1
is greater than or equal to the significance
threshold. Otherwise it is insignificant. Here, the integer significance represents a percentage,
so the significance threshold should be the ratio significance / 100. The trend of the company
is then calculated by looking at the last movementNumber consecutive movements as follows.
• If strictly more than half of these are significant increases, and the share price has overall
increased significantly over the whole period, then the trend is increasing.
• If strictly more than half of these are significant decreases, and the share price has overall
decreased significantly over the whole period, then the trend is decreasing.
• If strictly more than half of these are insignificant, and the share price movement over the
whole period is also insignificant, then the trend is stable.
• Otherwise, the trend is uncertain. This includes the case where there is insufficient data in
the history.
For example, suppose movementNumber = 3, and the last four values in a company’s share history
are [100, 105, 97, 103], so that the last three consecutive movements are +5, −8, +6. The overall
movement over this period is 103 − 100 = 3.
• If the significance threshold is equal to 3% (or less), then the trend is increasing: the
consecutive movements +5 and +6 both meet the significance threshold (this is a strict
majority of them), as does the overall movement.
• If the significance threshold is equal to 7% (or more), then the trend is stable: the consecutive
movements +5 and +6 are both within the stability threshold, as is the overall movement.
• If the significance threshold is equal to 5%, then the trend is uncertain: while there are two
significant increases in the consecutive movements, the overall movement is too small to be
significant.
• If the significance threshold is equal to 6%, then the trend is also uncertain: the consecutive
movement +5 is insignificant, −8 is a significant decrease, and +6 is a significant increase, so
there is no majority of consecutive movement type.
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1.3 (Basic)Strategy class (12 marks)
The investor will need to devise strategies determining when they should invest in a given company,
and how many shares they should buy when doing so. The building block for this will be a Strategy
interface, with a method invest(company) that takes as parameter a Company object, and returns
the number of shares to invest in based on the company’s current performance in the market. The
number returned is a signed integer, with a negative value indicating that the investor should sell
shares in that company.
The strategy should then be implemented through a BasicStrategy class. This class should
store a maxTransaction variable, indicating how much they are willing to invest or divest in shares
in a given transaction. It should also store variables movementNumber and significance. The
implementation of the invest(company) method should first calculate the company’s trend based
on these two variables, and then decide how much to invest/divest as follows.
• If the company’s trend is stable or uncertain, there is no investment to be made (the method
should return 0).
• If the company’s trend is increasing, the investor should buy shares. The number they buy
is equal to the maximal value such that they spend no more than maxTransaction on the
transaction.
• If the company’s trend is decreasing, the investor should sell shares. As above, the number
they sell is equal to the maximal value such that they receive no more than maxTransaction
from the transaction.
1.4 Investor class (16 marks)
Finally, your project should have an Investor class, responsible for managing investment in the
market (this could be an individual investor, or a company’s own investments in the market, for
example). Each investor should have a collection of companies (on the market) they are interested in
investing in. The investor should then associate to each of these a Strategy dictating how they will
invest, and the number of shares in the company they currently own. By default, Investor objects
are created with no companies of interest. They can also be created with a specified collection of
such companies together with their corresponding strategies, but no shares in any of the companies.
The various functionalities of the class are as follows.
• Investors can select a new company they are interested in, along with a specified strategy for
investing in that company (as above, initially they will have no shares in the company).
• Investors can decide they are no longer interested in a particular company. In that case, they
sell all the shares they currently own in that company, and it is removed from their collection
of interested companies.
• Otherwise, investment or divestment is entirely automatic, via an updateInvestment()
method. This updates the share prices of all companies the investor is interested in. For
each of these, the investor then runs the invest() method from the corresponding strategy,
and chooses to buy or sell shares according to this method’s output. This will potentially
modify the number of shares the investor currently holds in that company. Note that if the
output of invest() would cause the investor to sell more shares in a company than they
currently own, they should simply sell all of the owned shares.
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1.5 Code quality (10 marks)
The remaining marks (10) will be awarded for the quality of your code, as covered throughout the
semester in the Lectures and Labs.
• Keep your code neat and tidy; make sure it is properly indented throughout.
• Choose suitable names for variables and methods, respecting standard Java naming conventions.
• Comment your code as needed.
• Split your code into separate methods as appropriate; methods should not be too long.
2 Report (30 marks)
For this part of the assignment, you will write a report detailing how you designed, implemented,
and tested the program described in Section 1. The report should be typed into e.g. a Word
document, and submitted as a PDF (see Section 3 for more details). Where suitable in the report,
you should refer to specific lecture slides (or parts of Lab worksheets), e.g. “as seen in Lecture 10,
slides **-34”.
2.1 Collection choices (5 marks)
In the project, there are a number of classes which will use elements from the Java collection
framework. For example, the Market stores a collection of Company objects, while a Company stores
its history of share prices. For each use of a Java collection in your program, you should state and
justify here your choice of collection object. This section should be under one page in length.
2.2 OOP features (10 marks)
Over the course of the semester, you have learned a number of OOP features (e.g. encapsulation)
and principles (e.g. single responsibility principle). In your report, you will explain where you
have incorporated these in your design and how you have done so; include a brief definition of
the features/principles in question. Be as precise as possible, illustrating with small portions of
code if necessary. Note that not all the features and principles we saw in the lectures need to be
incorporated into your design; your report should only discuss those that are. This section should
be one-and-a-half to two pages in length.
Good example: The Single Responsibility Principle states that every class in the program
should have responsibility over a single functionality of the program; a class should do one thing.
This principle is incorporated into our class design: all the classes have their own, separate, purpose.
For instance, the Company class1
...
Bad example: Encapsulation and inheritance are two core features of OOP; they are used in
many parts in my program.
2.3 Testing description (10 marks)
As covered throughout the Lectures and Lab sessions in this module, testing is an essential part of
writing computer programs. In your report, you will include a description of how you tested the
1Give a brief description of the purpose of the Company class here.
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various parts of the program described in Section 1. You will state clearly what functionalities you
tested, and describe how you tested them, thinking carefully about possible corner cases. You may
include some sample code if you wish. You should test in the Controller class of your project,
using only tools and techniques that we covered in the Lectures and Labs throughout the semester.
You must NOT use any new or more advanced tools such as JUnit that weren’t taught. This
section should be one-and-a-half to two pages in length (screenshots excluded).
2.4 Model discussion (5 marks)
In this part, you should critically discuss the chosen investment strategy in BasicStrategy. Is
this a realistic model? What are some of its limitations? What would a more realistic strategy
look like? You may include possible implementations of alternate strategies if you wish. This part
should be no more than one page in length.
3 Submission instructions
In the dedicated “Coursework 3 submission” Assignment activity on the Learning Mall Online, you
will need to submit the following two (2) documents.
• A single ZIP archive of your entire NetBeans project. Include all the resources your
projec t needs to run. This file will be named _CW3_Project_studentId.zip”.
• Your report from Section 2, typed into e.g. a Word document, and converted into a PDF
file. This file will be named “ _CW3_Report_studentId.pdf”.
The submission deadline is: Sunday, 26 May, 2024, at 23:59 (China-time).
This assignment is individual work. Plagiarism (e.g. copying materials from other sources
without proper acknowledgement) is a serious academic offence. Plagiarism and collusion will not
be tolerated and will be dealt with in accordance with the University Code of Practice on Academic
Integrity. Submitting work created by others, whether paid for or not, is a serious offence, and
will be prosecuted vigorously. The use of generative AI for content generation is not permitted
on this assignment. Such a use would be considered in breach of the University Code of Practice
on Academic Integrity, and dealt with accordingly. Individual students may be invited to explain
parts of their code in person during a dedicated interview session, and if they fail to demonstrate
an understanding of the code, no credit will be given for that part of the code.
Late submissions. The standard University policy on late submissions will apply: 5% of
the total marks available for the component shall be deducted from the assessment mark for each
working day after the submission date, up to a maximum of five working days, so long as this does
not re duce the mark below the ; submissions more than five working days late will
not be accepted.
We can - and will - discuss some aspects in the Lab sessions,
and of course, as usual, you can ask me anything by email, during Office Hours, or in the LMO
Forums. Good luck!
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