CSE500 Programming HW4

CSE 500 – Fall 2004

PROGRAMMING HW4

This programming assignment requires you to define 3 classes as described below. It should be sent via email to your instructor before the due date. Programs that do not compile cannot be graded.

ATTENTION: Any changes made to this document from the original posting are denoted in blue.

Part #1 - NYSECorporation Class

INTRODUCTION

In HW 3, you wrote a GUI that allowed the user to enter information necessary to calculate and compare the market caps of 2 companies. Programs such as this are very limited. Once they are written, they can only be used in that single capacity. In order to make code re-usable and flexible for many applications, we may use the principles of object oriented programming (OOP). Using OOP we can create a class (NYSECorporation) that will store all the data about a given corporate stock, and will perform some useful functions. NYSECorporation objects would then serve as unique data types that could be used in many different ways in all sorts of programs.

CODING

Define the NYSECorporation class such that it implements Comparable and follows the requirements below. Note that this class should be built general in nature such that it can be used effectively by many different applications:

Data - Each NYSECorporation object represents a different company traded on the New York Stock Exchange, so each object must maintain its own data concerning:

the name of the company, which must be at least 1 character long, but no more than 30
the ticker symbol, which follows the rules of HW3
the shares outstanding, which cannot be negative
the current stock price, which cannot be negative

You must use complete information hiding for all data in your class.

Default Constructor - Provide a default constructor where your instance variables are each assigned default values that signify they have not been assigned valid values. For example, use “NONE” for the name & ticker symbol, use 0 for the shares outstanding & stock price.
Second Constructor - Provide a second constructor that allows for the construction of a NYSECorporation object while providing custom initialization of all the object data. Your constructor must make sure that someone doesn't try to initialize the object using illegal values (according to the data rules). Should this happen, your constructor should throw an exception.
Accessor methods – Provide accessor methods for all of your object data.
Mutator methods – Provide mutator methods for all your object data that ensures invalid values (according to the data rules) are not assigned to your data. Should an invalid value be provided your class should throw an exception.
public double calculateMarketCap() method - This method should compute and return the market cap in dollars of the company as currently valued.
public int compareTo(NYSECorporation anotherStock) method – This method should work similarly to the String class’ compareTo method, except we’ll use market cap as a basis for our comparisons. So, this method compares the referenced object to the anotherStock object, and returns a number < 0 (use -1) if the market cap of this object is smaller than anotherStock, 0 if they are equal, and a number > 0 (use 1) if anotherStock is the smaller of the two.
public String toString() method - This method should return a textual (String) representation of the referenced NYSECorporation object on a single line such that each piece of information appears in its own "column". This summary info could then be displayed inside a JTextArea in tabular form. To implement this method, start with an empty String variable inside this method (ex: String str = "";), and gradually concatenate (+=) more text onto it, separating data using tabs. Your method is simply building a String summarizing the object. This summary information should include:

Name of the company
Ticker symbol in parenthesis
Current stock price in proper format (exactly 2 decimal points)
Shares outstanding (with appropriate commas)
Current Market Cap (abbreviated form as in HW 3, ex: $350 billion)

DISPLAY GUIDELINES

When displaying your information, all money should be displayed using exactly 2 decimal digits. In addition, commas must be used to separate thousands, millions, etc... for any large numbers. For help in displaying your numbers properly, you may use the NumberFormat class, which automatically formats numbers according to your liking. To use this class, remember to add the following code to the very top of your program, even before the class header:

import java.text.NumberFormat;

This will make this class available to your program. The setMaximumFractionDigits and setMinimumFractionDigits methods from this class allow us to display a real number to a specified number of decimal points. Commas are automatically inserted as numbers get large. To use the class, you will call the format method to create a String representation of the number you provide in the format you desire. This method will return such a String. The OutputDoublesDriver class below gives an example of how one might use this class to print out a number using differing precision. Try running the program below, changing the precision and see what happens.

import java.text.NumberFormat;

public class OutputDoublesDriver

    public static void main(String[] args)

      double num = 12345.6789;

      System.out.println("num unformatted: " + num);

      NumberFormat nf = NumberFormat.getInstance();

      nf.setMaximumFractionDigits(1);

      nf.setMinimumFractionDigits(1);

      String formattedNum = nf.format(num);

      System.out.println("num formatted = " + formattedNum);

Part #2 – StocksManager Class

CODING

Now that we have a class for representing a single stock, it is time to create a class to manage many such objects. Define the StocksManager class such that it manages any number of NYSECorporation objects. It should have the following:

Data - Each StocksManager object should have a data structure for managing NYSECorporation data. You may use an array, Vector, ArrayList, or any other data structure you like. This data structure will have to be flexible such that it can hold any number of objects.

You must use complete information hiding for all data in your class.

Default Constructor - Provide a default constructor for initializing the object.
public void addStock(NYSECorporation stock) method- Provide a method for adding new NYSECorporation objects to your data structure. You may simply add them to the end.
public void sortStocksByTicker() method – This method should sort the data stored in the data structure alphabetically (A-Z) by the ticker symbol.
public void sortStocksByMarketCap() method – This method should sort the data stored in the data structure by market cap in decreasing order.
public String toString() method – This method will provide a textual representation of the object, which should be a table of all the objects in the data structure.

Part #3 – StockBuilder class

CODING

Define the StockBuilder class such that is executable (has a main method) and starts a GUI. It should have a StocksManager object instance variable, and the GUI should provide the following:

· Text Area Summary – Your StockBuilder class is going to be used to gradually build and display a StocksManager object. So, your GUI should have a text area that lists all the stocks currently stored by your StocksManager object in tabular form. This means it should look like a table, with each stock taking its own row.

· Enter Data for a Stock – provide labeled text fields (similar to HW 3) that allow a user to enter data about a single stock. See the NYSECorporation class to see what data is necessary to be entered.

· Add stock button – when pressed, this button will extract all the information in the text fields and use it to construct a new NYSECorporation object, which will then be added to the StocksManager object. Finally, after the StocksManager object is updated, the text area should display its updated data.

· Sort by ticker symbol button – when pressed, this button should sort the StocksManager by ticker symbol and update the display inside the text area.

· Sort by market cap button – when pressed, this button should sort the StocksManager by market cap and update the display inside the text area.

NOTE: You should not be performing any redundant operations inside this class. Do not repeat what you did inside your NYSECorporation or StocksManager classes here. Take advantage of the code you wrote in those classes.

NOTE: You may add whatever helper methods to these 3 classes that you like.

REMEMBER TO MAKE YOUR PROGRAM ROBUST

Make sure that your program anticipates erroneous input such that it never crashes. I ill try to enter all sorts of illegal input like letters for numbers, negative stock prices, etc... to check if your program will handle such problems. Your program should handle such cases without crashing. In addition, whenever someone enters incorrect information, you should inform the user of their error (continue to use JOptionPane).