S428 Advanced Application Development

Assignment 1

Due Friday, Jan 28 by 11:59PM.

• Write a Java program that performs a currency conversion using a built-in conversion table. You will find conversion tables from many different sites, but the one that you should use for this assignment is available from http://www.xe.com/ict/. If you go to this web site, select the base currency as US Dollars, select "most recent rate" for the conversion date and generate the conversion table in "fixed width format", it will create a table in plain text that looks like the following:

  Currency Unit                            USD per Unit        Units per USD
  ====================================   =================   =================
  DZD Algeria Dinars                       0.0139694                71.5850      
  USD United States Dollars                1.00000                   1.00000     
  ARS Argentina Pesos                      0.340716                  2.93500     
  AUD Australia Dollars                    0.757445                  1.32023
  EUR Euro                                 1.30411                   0.766809    
  

• The first part of your task would be to somehow incorporate this data into your program. One way to do this would be to use Microsoft Excel to import the data (generating a HTML table would make it easy to bring the data into Excel - you can just copy and paste), and then creating a formula to generate the Java array declaration for the array(s) that you need to store this information. Another method would be to store the information in a file, and then use your program to read the information into the arrays. How you actually do it is up to you. This part of the problem can be treated as collaborative, although everyone has to convert the data individually. You can post a description of how you do it on the forums, and if you are having problems with any specific thing you try, ask the opinion from the class on your method.
• Once you have the table in your code, the next step is to use this table for the purpose of interactive conversion. There are two types of conversion - for the sake of simplicity, lets say we call the ToDollars and FromDollars. ToDollar conversion works like this: 100 Euros ToDollar gives 130.41 dollars, and 100 FromDollar to Euro gives you 76.68 Euros.
• You will need to interactively ask the user for an amount and the target currency, and generate the result of conversion both ways. You will need to ensure that your program is somewhat intelligent to find all the currencies that match the currency asked for. So if someone says, Dollar, it should match US Dollars, Australia Dollars, and so on. Also, you should allow people to search on partial matches, so someone can search for Aus as the target, and you should be able to find both Austria as well as Australia. The more intelligent you are the better, but the baseline of course is a complete match for the currency code (e.g., USD) or the currency name (e.g., United States Dollars).
• Name your java program Convert.java
• Remember that you should only make ONE instance of the Input class! Also, make sure you take the inputs in the same order as shown in the sample output. If you change the order of inputs, your submission will not work properly! Feel free to change the prompts and the text that is printed by your program though.
• Sample output. The following is a sample of how your program would look like. User inputs are shown in red.

  Welcome to my fancy(not!) conversion program!
  Please enter the amount you want to convert,
  And the target currency to compute.
  Enter a negative amount to quit.
  ---
  
  Enter the amount:  100
  Enter the target currency:  usd
  ToDollar: USD 100.0 (United States Dollars) yields $100.0
  FromDollar: $100.0 yields USD 100.0 (United States Dollars)
  ---
  Enter the amount:  150
  Enter the target currency:  mala
  ToDollar: MYR 150.0 (Malaysia Ringgits) yields $39.47
  FromDollar: $150.0 yields MYR 569.99 (Malaysia Ringgits)
  ---
  Enter the amount:  200
  Enter the target currency:  euro
  ToDollar: EUR 200.0 (Euro) yields $260.82
  FromDollar: $200.0 yields EUR 153.36 (Euro)
  ---
  Enter the amount:  50.35
  Enter the target currency:  rupee
  ToDollar: INR 50.35 (India Rupees) yields $1.15
  FromDollar: $50.35 yields INR 2197.78 (India Rupees)
  ---
  ToDollar: PKR 50.35 (Pakistan Rupees) yields $.85
  FromDollar: $50.35 yields PKR 2992.05 (Pakistan Rupees)
  ---
  Enter the amount:  75
  Enter the target currency:  help
  Sorry - no information about currency help
  ---
  Enter the amount:  -1
  Bye-bye!
  

Some notes and hints

• Comment your code well! A good portion of the points would be allocated towards readability of your code.
• Make heavy use of the Java class documentation! As shown in class, the String documentation is available at http://java.sun.com/j2se/1.4.2/docs/api/java/lang/String.html
• You can use the following to truncate the number of decimal places:

        import java.text.*;
  
        public class Whatever {
        ...
        double x = 99.9974835;
        System.out.println(new DecimalFormat(".##").format(x));
        ...
        

  Notice that the import must be before your class declaration.
• Reading from files is not a very easy task in Java, but for those of you who want to try, here are a few things that would help.
  1. A class, just like Input.class provided, but this one reads from a file! Download: FileInput.class
     To create an instance of this class, use:

     				FileInput inp = new FileInput("myfilename.txt");
     			

     The rest is just like the Input class. Note that you should still use an Input class for reading the users' inputs.
  2. To convert a string to a double, you do the following:

     				String thisstring = "5.343453";
     				double myval = new Double(thisstring).doubleValue();
     			

Submission method You will need to submit your assignment using the online submission system. To submit, use the following steps:

• Point your web browser to The S428 Handin Page If your browser asks if you want to display the non-secure items, say Yes (the only non-secure thing in that page is the s428 icon, so don't worry :) ).
• Type in your email address (including the @indiana.edu part) and your student ID without any dashes or spaces in the appropriate boxes.
• Upload the two files for submission in the two fields provided by clicking on the Browse button and selecting the appropriate file. If you are using steel to write your code, you will need to download the java files from steel to the machine where you are using the web browser. Submit only the .java files. No class files. Follow the namig convention as stated in the assignment.
• Click on "Submit Assignment", and wait until you get the confirmation page. This may take a couple of minutes - do not click multiple times. The system will display a confirmation page.
• You are not done yet! Check your email for a confirmation email from the submission system. It may take upto 5 minutes for you to receive the confirmation email. Make sure you read and understand the email, including the information that it gives you. Do not assume that your assignment submission was successful until you receive an email with no error message. Look in particular for the file "CompilationErrors". If it says "Empty file!" for this, you are fine. If any compilation errors are shown, you will need to fix them. Your assignment will be severly penalized if you have compilation errors.
• You may submit as many times as you would like - future submissions will overwrite any file submitted with the same name. If you change only one file, you can submit only that file. The confirmation message will include all files submitted so far. Keep a copy of the confirmation message. This will be proof that your submission was successful in the case of a system glitch later.