Description
Objective
This assignment’s objective is to write a console-based Java application with which a travel agent could
present options for travel destinations to a client who wants to redeem his or her accumulated frequent flyer
miles. For the sake of simplicity, we will assume all trips depart from O’Hare International Airport and that
the miles represented are required for a roundtrip ticket.
Depending on the distance, each destination requires a different number of frequent flyer miles to obtain a
roundtrip ticket. Note that, if the client travels during the “off season”, he or she may be able to take
advantage of the “off season”, or “super-saver”, mileage of a destination that requires fewer miles to obtain
a roundtrip ticket to that particular destination.
Input File
A list of destination cities and related ticket redemption information will be read from a file (one named
destinations.txt is provided for you but you may create your own). The file is formatted with one
city, or destination, per line, with the first five items, or fields, separated by a semicolon ( ; ) and the last
two separated by a hyphen ( – ) as shown in the example below. The six items regarding a single destination
represent:
The destination city name; the normal mileage needed for an economy class ticket; the “super-saver”
mileage needed for an economy class ticket; the additional mileage needed for upgrading from economy to
first class; the beginning month of departure during which “super-saver” mileage can be used instead of
the normal mileage – the ending month of departure during which “super-saver”, mileage can be used
instead of the normal mileage.
Actual Input File:
Berlin;17250;12750;5250;3-5
Hong Kong;30000;20250;17500;2-4
Hyderabad;30000;20000;15000;2-4
New York;10000;5000;8000;10-11
Paris;20000;15000;10000;2-4
Sidney;50000;30000;20000;5-6
Tokyo;29000;16500;5350;2-5
Vienna;17500;12500;5000;2-4
Washington, D.C.;9000;7500;2000;10-12
The above are the contents of file destinations.txt as attached to the Assignment on Blackboard.
Redemption Algorithm
Your algorithm should 1) try to get tickets that travel the farthest, 2) use “super-saver” mileage whenever
possible, 3) try to display as many different tickets as possible given the information, and, only after you
have determined the destinations to which the customer can fly, 4) determine if you can use the remaining
mileage for upgrade for any of the destinations to which the customer is eligible to fly (try to upgrade the
longest trip first, then the next-to-longest – if there is one, etc.).
CSCI 470/502 Assignment 4 – Mile Redeemer Console App Page 2 of 6
The Classes
Destination
Write a class that encapsulates information such as the name of the destination city; normal miles required
for a ticket; “super-saver” miles required to for a ticket during the “off season” months; additional miles for
upgrading from economy to first class; start month of the “off season” and end month of the “off season”.
Private instance variables and public accessor methods should be written for this information.
MileRedeemer
Write a class to encapsulate the logic for redeeming mileage. This class should have private instance
variables for an array of Destination objects, and an integer to represent the remaining miles after the
user’s Frequent Flyer Miles have been redeemed.
Define the following methods in the MileRedeemer class:
• public void readDestinations(Scanner fileScanner)
For this method, we use a Scanner object as the input parameter for flexibility and reusability. For
example, we could reuse the method to read files from different sources. This method should use
the Scanner object to read and parse the destination data into an array of Destination objects.
Before ending, the method should sort the array of Destination objects in descending order by normal
mileage (see more information about sorting below).
• public String[] getCityNames()
This method should loop through the array of Destination objects and create an array
of String objects from the city names. This array can be sorted in ascending order and returned (to be
printed out by the main app) just for the display of all possible destinations.
• public String[] redeemMiles(int miles, int month)
For this method, miles is the total available miles, and month is the desired month of departure. To
avoid writing one huge method, you can (and probably should) have the redeemMiles() method call
some other methods to accomplish subtasks as part of the larger overall algorithm. This method should
return an array of String objects containing descriptions of redeemed tickets to be printed out by the
main app. It should also save the miles remaining after the tickets have been redeemed.
• public int getRemainingMiles( )
This method should return the saved remaining miles.
MileRedemptionApp
This is the main app class that will have the main( ) method and will drive the entire process.
First declare a Scanner object for the keyboard and prompt the travel agent for the name of the .txt file
of destinations. Next, it should declare another Scanner object to read the destination records from the
CSCI 470/502 Assignment 4 – Mile Redeemer Console App Page 3 of 6
file. This Scanner will be the Scanner parameter passed to the readDestinations() method of the
MileRedeemer class where the array of destinations will be created.
Once back from readDestinations(), use getCityNames() to get and print the list of all possible
destinations. Prompt the travel agent for the client’s Frequent Flyer Miles balance and for the client’s month
of departure. Using these two integers, call redeemMiles() to determine the destinations available to
which the client can fly and present them to the travel agent.
Note that, if redeemMiles() returns an empty array, print an appropriate message such as:
*** Your client has not accumulated enough Frequent Flyer Miles ***
Either way, then use getRemainingMiles() to present the Frequent Flyer Miles remaining after
determining the destinations to which the client can fly.
After presenting the possible destinations and remaining miles, prompt the travel agent asking if he or she
would like to start over. Do not ask for a new file name, do not print the header statement and do not print
the list of all possible destinations again. Let the travel agent answer with ‘y’ or ‘Y’ or ‘yes’ or ‘Yes’ and, if
he or she answers in the affirmative, the next thing he or she should see is a prompt to enter the client’s
Frequent Flyer Miles and departure month and the process of determining a new list of possible destinations.
MileageComparator
Because the cities in the input text file are almost always out of order based on normal miles, the
readDestinations() method will need to sort them in descending normal miles order before any
redemptions can be done. The class java.util.Arrays has a static sort() method that takes an array
and an implementation of Comparator. The latter is an object of a class that defines the ordering:
import java.util.Comparator;
public class MileageComparator implements Comparator
{
@Override
public int compare(Destination d1, Destination d2)
{
return (d2.getNormalMiles() – d1.getNormalMiles());
}
}
Note that this class is optional as you may be able to find a different way to implement the Java interface
Comparator. For example, create an inner class.
Note: The array of city name strings created and returned by getCityNames() can also be sorted using
a version of Arrays.sort(). There’s no need to write a Comparator in this case, though, as the “natural
ordering” of the strings will be sufficient.
(continued)
CSCI 470/502 Assignment 4 – Mile Redeemer Console App Page 4 of 6
Programming Notes
Exception Handling and Input Validation
For simplicity’s sake, please do not add try catch blocks for exception handling and do not do any sort of
input validation.
File I/O and String Parsing
The Scanner class can be used to read the lines from the file. Before reading the lines, a
java.util.ArrayList should be created:
ArrayList destinationList = new ArrayList();
As lines are read from the input file, the lines need to be parsed, or broken into fields, using “;” as the
delimiter. Instances of Destination are created and added to the array list. There are a variety of
different ways to parse a String into fields. One easy way is to use the split() method of
the String class. Note that the last two fields, i.e., begin month and end month for the “Frequent Flyer”
months, are separated by a hyphen.
To change a String to an integer to assign to the three miles instance variables and the beginning and
ending month instance variables, use wrapper class Integer’s method parseInt().
After the whole file is read, the ArrayList can be converted to a normal, fixed-length array of objects:
Destination[] destinationArray = (Destination[]) destinationList.toArray(new
Destination[destinationList.size()]);
By doing this, we can take advantage of Java’s built-in methods for sorting an array.
Reading the File
So that you will not have to do any exception handling, add the following at the end of the method
declaration that reads the input file (no semicolon at the end of it):
throws IOException
IMPORTANT
Please read the Java Coding and Documentation Guidelines document in Course Documents on
Blackboard before submitting your final app for grading.
Submitting the Assignment
The assignment will be submitted on Blackboard. Please submit the three (or four) .java files on
Blackboard. DO NOT ZIP THEM AND DO NOT SUBMIT THE INPUT FILE!
(Exact output follows)
CSCI 470/502 Assignment 4 – Mile Redeemer Console App Page 5 of 6
Exact App Output Using the File destinations.txt Provided
Please enter the name of the file: destinations.txt
—————————————————————-
WELCOME TO THE JAVA AIRLINES MILES REDEMPTION APP
—————————————————————-
List of destination cities your client can travel to:
Berlin
Hong Kong
Hyderabad
New York
Paris
Sidney
Tokyo
Vienna
Washington, D.C.
—————————————————————-
Please enter your client’s accumulated Frequent Flyer Miles: 49600
Please enter your client’s month of departure (1-12): 4
Your client’s Frequent Flyer Miles can be used to redeem the following tickets:
* A trip to Hong Kong in Economy Class
* A trip to Hyderabad in Economy Class
* A trip to Washington, D.C. in Economy Class
Your client’s remaining Frequent Flyer Miles: 350
—————————————————————-
Do you want to continue (y/n)? y
—————————————————————-
Please enter your client’s accumulated Frequent Flyer Miles: 3421
Please enter your client’s month of departure (1-12): 3
*** Your client has not accumulated enough Frequent Flyer Miles ***
Your client’s remaining Frequent Flyer Miles: 3421
—————————————————————-
Do you want to continue (y/n)? y
—————————————————————-
Please enter your client’s accumulated Frequent Flyer Miles: 154351
Please enter your client’s month of departure (1-12): 7
CSCI 470/502 Assignment 4 – Mile Redeemer Console App Page 6 of 6
Your client’s Frequent Flyer Miles can be used to redeem the following tickets:
* A trip to Sydney in Economy Class
* A trip to Hong Kong in Economy Class
* A trip to Hyderabad in Economy Class
* A trip to Tokyo in First Class
* A trip to New York in Economy Class
Your client’s remaining Frequent Flyer Miles: 1
—————————————————————-
Do you want to continue (y/n)? n
————————————————————————-
THANK YOU FOR USING THE JAVA AIRLINES MILES REDEMPTION APP
————————————————————————-
