(Most recent update: Wed, Nov 10 at 8:20am. Look for red "Update:" tags.)

Objective

This homework will give you practice designing object-based solutions to problems. In addition, it will allow you to practice arrays of references and javadoc documentation.

Overview

For this homework you will implement a program that keeps track of customers and movies in a video store. Your program will allow employees to add customers to the database, to add movies, to change the status of a movie (from available to rented), etc. Different from other homeworks, we will not provide any support infrastructure for this project. You will design and implement all the classes needed to complete the video store application. More details about the program are provided in the Specifications section. You may want to take a look at the Sample Run section before you read the detailed description.

This homework will be graded as follows:

• 65% - Implementation
• 25% - Design
• 10% - Time log

Specifications

Program Tasks Overview

You will write a program that enables an video store employee to complete the following tasks:

• Add a movie to the collection of movies (database) available for rent.
• Find information about a movie.
• Search for movies in the database with a specific genre (type) and/or from a particular year on.
• Add a customer to the collection of customers (database) that can rent movies.
• Find information about a customer.
• Remove a customer from the database.
• Rent a movie.
• Return a movie.
• Print all the movies in the database.
• Print all the customers in the database.

Assumptions

• Customer' names are unique and consist of a first name and last name (no middle initial).
• Movies' titles are unique.
• A customer rents a movie and immediately pays for it.
• The store keeps only one copy of each movie title.
• When the program is started there are no customers or movies in the system.

What you must implement, in a nutshell

You must design a solution to the video store application. The design will describe each of the classes that are part of the application and which methods each one has. We have intentionally only provided the most critical classes. You are expected to design your own classes for representing the basic entities that the program manipulates. You will document your design in the design.txt file, which is part of the code distribution. See the section on design documentation below. After completing your design, you will implement it. The number of classes you decide to use is up to you, however you have to follow a set of restrictions specified below.

Code Distribution

Before you read these specifications, you should access the files associated with this homework by checking out the project named p6. The code distribution provides you with the following:

• Example.java - Illustrates how to access the video store application via the VideoStore class.
• Tests.java - Java file that test the functionality of the application's driver class (VideoStore.java).
• design.txt - Text file where you will provide a description of your design.
• A time log file.
• Test1Results.txt and Test2Results.txt - Text files used by the Tests.java module to check your results against the expected results.

Database Representation

The database of the video store application will be represented using two sorted lists:

• Customers list - A list of customers sorted by lastname and firstname.
• Movies list - A list of movies sorted by title.

How you represent these lists is part of your design. You can follow any approach you understand is necessary as long as it adheres to the specifications of the homework. Notice that you will not use any sorting algorithm in this project. You will keep your lists sorted by inserting elements in the appropriate position in the list.

Required Classes

You must implement and use the following classes:

Customer

This class represents a customer. A customer is identified by a name (firstname and lastname), address, and an array of movies that the customer currently has rented. As long as you defined an array of movies as part of the instance variables of this class you will be okay. We leave it up to you to define the methods you will need.

(Update: (Mon, Nov 8, 11:00pm) Added "currently" above. Throughout, when we talk about the videos that a customer has rented, we mean "currently" rented.)

VideoStore

This class represents the video store application. Actually, this is the class we will use to test your program. Access to the video store application is through this class. The methods' prototypes and behaviors are defined next:

• Error Conditions

Several of the methods to be described below generate a set of error conditions identified with the following integer values:

Condition	Integer Value
CORRECT	0 (No error)
INVALID_NAME	1
INVALID_MOVIE	2
NONZERO_MOVIES	3
INVALID_MOVIE_RENTED	4

• Methods (all are public methods)
• addMovie: Adds a movie to the collection of movies. The collection of movies is kept sorted by title. The method prototype is given below:
boolean addMovie(String title, int year, String genre)

The year parameter represents the year the movie was released. The genre parameter refers to the film's genre (e.g., Action, Horror, Romance, etc.). This method will return true if the add operation was completed successfully and false if the movie is already part of the database.

• findMovie: Returns a String with information about the movie or null if the movie is not part of the database.
String findMovie(String title)

If the movie is not currently rented, the format of the String to return is:

MovieString ® Title: "title", Year: year, Genre: genre

where title, year, and genre correspond to the movie's title, year and genre. If the movie is currently rented then the format is:

MovieStringRented ® Title: "title", Year: year, Genre: genre (RENTED)

• findMovies: Returns a String with those movies that have the specified genre (e.g., Horror, Action, Romance, etc.) and that were released on or after the specified year.
String findMovies(String genre, int year)

If genre is null then the genre is ignored in the search process. If year is -1 the year value is ignored in the search process. The method will return null if no movies satisfy the search criteria. The format of the String to be returned is a sequence of MovieString each on a line by itself. We refer to this list as the MovieList.

• addCustomer: Adds to the database the customer whose name and address are specified in the parameters.
boolean addCustomer(String firstName, String lastName, String address)

The collection of customers is kept sorted by customer name. For example Rose Johnson will appear before Albert Smith. The method will return true if the add operation was successful and false if the customer is already part of the database.

• findCustomer: Returns a String with information about a customer or null if the customer is not part of the database.
String findCustomer(String firstName, String lastName)

The format of the String to return is one of the following. If the customer has no rented movies the result is:

CustomerString ®

Name: name
Address: address
No movies rented.

If the customer has rented movies the result is:

CustomerString ®

Name: name
Address: address
Movies (rented):         (See the note just below.)
MovieList

where the format MovieList was given above.

(Update: (Tue, Nov 9 at 9:20am) Added the line "Movies (rented):" above and updated the following note.)

(Important Note: Due to a bug in our initial implementation, there was an extra space on line 39 of the file "Test2Results.txt", after the line "Movies (rented):". This was fixed on Friday, but people who checked the file out early may still see the space there. If so, you will fail to pass the test. To fix it, simply checkout the latest version of the file "Test2Results.txt" or remove the space yourself.)

• removeCustomer: Removes the specified customer from the database.
int removeCustomer(String firstName, String lastName)

The following error conditions can arise while removing a customer from the database. Each of these conditions will be verified in the order to be presented next. Once an error condition has been recognized, the method will return that condition and ignore the rest. For this method the error conditions are:

• INVALID_NAME - No customer with the given name is in the database.
• NONZERO_MOVIES - The customer still has some rented movies, and so cannot be removed.

If neither of these errors occurs, the value CORRECT should be returned.

• rentAMovie: A reference to the specified movie is added to the array of movies associated with the specified customer.
int rentAMovie(String firstName, String lastName, String title)

The following error conditions can arise as a result of this operation. These conditions must be tested in the following order. Once an error condition has been recognized, the method will return that condition and ignore the rest.

• INVALID_NAME - No customer with the given name is in the database.
• INVALID_MOVIE - No movie with the given title is in the database.
• INVALID_MOVIE_RENTED - The specified movie is part of the database, but it is currently being rented.

If none of these errors occurs, the value CORRECT should be returned.

• returnAMovie: Removes the reference to the specified movie from the array of movies associated with the customer.
int returnAMovie(String firstName, String lastName, String titleIn)

The following error conditions can arise as a result of this operation. These conditions must be tested in the following order. Once an error condition has been recognized, the method will return that condition and ignore the rest.

• INVALID_NAME - No customer with the given name is in the database.
• INVALID_MOVIE - No movie with the given title was rented by the customer.

If none of these errors occurs, the value CORRECT should be returned.

• allMovies: Returns a String with all the movies in the database.
String allMovies()

The format of the string is defined by MovieList above. A value of null will be returned if there are no movies in the database.

• allCustomers: Returns a String will all the customers in the database.
String allCustomers()

The format of the String to be returned is a sequence of CustomerString each on a line by itself. We refer to this list as the CustomerList. A value of null will be returned if there are no customers in the database.

• toString: Returns a String with the all the movies in the database followed by all the customers in the database.
  String toString()

  This is just the list of movies followed by the list of customers, that is:
  DatabaseString ®

  MovieList
  CustomerList

Additional Classes

As part of your design you will need to define classes in addition to the ones described above. Think carefully about the classes you will need. A good design can simplify dramatically the amount of time you will spend implementing your design. We recommend you implement a class called Name which represents a customer's name. It will have, among other methods, a method that will compare two names so you can insert names in sorted order.

Requirements

• To implement the sorted lists you may not use any of the Java API data structure classes (such as ArrayList), just simple ones like String. The lists must be created using array of references to objects of classes you defined.
• Provide complete javadoc documentation for one of the classes you designed. (That is, a javadoc comment for the entire class and individual javadoc comments for all the public methods.) Indicate in the design.txt file which class you are providing javadoc documentation for.
• Remember, you must define the classes Customer and VideoStore.
• As mentioned above, you are expected to design your own classes for the various entities used in this project. You will lose a significant number of points if your program only defines the classes Customer and VideoStore.
• As with all programming assignments:
  • You must use meaningful variable names and good indentation.
  • You must avoid code duplication, by calling appropriate methods (rather than cutting and pasting code). You may define your own private utility methods to perform often repeated tasks.
  • Because we are using an automatic testing system, it is important the you adhere closely to the specifications. In particular, please do not change the names of any of the classes you are to implement, and use signatures given above for your methods.
  • Try your best to use the Eclipse/CVS submit option for your submission. If you are having problems with this, please contact us. Use the submit server only as a last resort for submitting your program. If you find it necessary to use the submit server, please see the following page for information on jar creation for submission.

  Because of the difficulty in grading emailed submissions, we will start deducting points unless you submit via the submit option or the submit server.

• To have confidence that your classes have been implemented correctly, execute them using the provided tests (Tests.java). Of course, you should also perform your own testing to be sure.
• Submit your project even if you are not able to complete all the functions. However, for those methods of the VideoStore class that you could not implement provide a shell (empty body) for the method. This will allow us to compile your program and test the components you have implemented.

(Update: (Sat, Nov 6 at 8:45pm) The following section added.)

Design Documentation

The following describes the format of the design.txt file you are expected to provide. Your design file should have three parts:

I. Classes

Lists the classes (just the names) you have chosen as part of your design. Provide a brief (one or two lines) description of each class. You do not need to include the VideoStore class.

II. Methods

For each class, lists the methods (just the names) that you have defined. Provide a one line description for each method.

III. Javadoc Class

Give the name of the class that you provided javadoc for.

Sample Run

At the end of this page you will find a class Example.java and the output that it produces. Access to the application is through the VideoStore class, which you will implement. The class Example.java can be found in the code distribution.

(Update: (Wed, Nov 10 at 8:30am) The following section added.)

JavaDoc

As mentioned above, you are to provide javadoc documentation for one of your classes, and will indicate which class in your design.txt file.

You should not provide the html files generated by the javadoc utility with your submission. We will generate the files ourselves.

To run Javadoc from Eclipse, select the file, right click, and select "Export → Javadoc". The first time you attempt to do this, Eclipse will ask you to specify the location of your javadoc executable. This file will be located in your Java j2sdk directory, within its bin directory. For example, on a typical Windows machine, this might be

C:\j2sdk1.4.2_05\bin\javadoc.exe

On a typical Unix/MacOS machine the file will likely just be called "javadoc", and again will be in the Java sdk directory.

Remember to store the file outside your workspace. When exporting javadoc it will ask you for the "Destination" to store the javadoc documentation files. Please specify a directory that is outside of your Eclipse Workspace, so it does not affect your submission.

Challenge Problem

Remember that you are not required to implement the following problem. Please visit the course web page for information regarding challenge problems. IMPORTANT: If you decide to complete the challenge problem you must provide its implementation in the file called Challenge.java.

The challenge problem consists of defining a GUI for the video store application. The GUI should allow a user to complete all the tasks associated with the VideoStore class.  Feel free to define your interface as you understand is best, providing any error messages you understand are appropriate.   Remember to define a main method in the Challenge class that allow us to run your program.

Submission

Submit your project using the submit project option associated with Eclipse. Remember to complete your time log before submitting your homework.

Example.java

(This is provided in the code distribution.)

public class Example {
    public static void loadMovie(VideoStore videoStore,
            			   		 String title,
            			   		 int year,
            			   		 String genre) {
        System.out.println("Adding movie: \"" + title + "\"");
        videoStore.addMovie(title, year, genre);
        System.out.println("***VideoStore Database***");  
        System.out.println(videoStore);
        System.out.println();
    }
 
    public static void loadCustomer(VideoStore videoStore,
			   						String firstname,
			   						String lastname,
			   						String address) {
        System.out.println("Adding customer: " + firstname + " " + lastname);
        videoStore.addCustomer(firstname, lastname, address);
        System.out.println("***VideoStore Database***");  
        System.out.println(videoStore);
        System.out.println();
    }
    
    public static void main(String[] args) {        
        String results = "", info;
        
        VideoStore videoStore = new VideoStore();
        
        /* Adding some movies and printing the database status after each add */
        loadMovie(videoStore, "Eclipse", 2004, "Horror");
        loadMovie(videoStore, "Compilation in Outer Space", 1976, "Action");
        loadMovie(videoStore, "A Simple Homework", 1990, "Comedy");
        
        /* Adding some customers and printing the database status after each add */
        loadCustomer(videoStore, "John", "Smith", "8th Street Bethesda CA");
        loadCustomer(videoStore, "Rose", "Peterson", "101 Road RiverTown CA");
        System.out.println("***All movies***\n" + videoStore.allMovies() + "\n");
        System.out.println("***All customers***\n" + videoStore.allCustomers());
        
        System.out.println("\n***Looking for Horror movies***");
        if ((info = videoStore.findMovies("Horror", -1)) != null)
            System.out.println(info);
        
        System.out.println("\n***Looking for movies released on or after 1989");
        if ((info = videoStore.findMovies(null, 1989)) != null)
            System.out.println(info);    
        
        System.out.println("\n***John Smith is renting the movie \"Eclipse\"");
        if (videoStore.rentAMovie("John", "Smith", "Eclipse") == 0) 
            System.out.println(videoStore);
     
        System.out.println("\n***Looking for the movie \"Eclipse\"");
        if ((info = videoStore.findMovie("Eclipse"))!= null)
            System.out.println(info);
          
        System.out.println("\n***John Smith is returning the movie \"Eclipse\"");
        if (videoStore.returnAMovie("John", "Smith", "Eclipse") == 0)
            System.out.println(videoStore);
    }
}

Output of Example.java

  Adding movie: "Eclipse"
  ***VideoStore Database***
  Title: "Eclipse", Year: 2004, Genre: Horror
  
  Adding movie: "Compilation in Outer Space"
  ***VideoStore Database***
  Title: "Compilation in Outer Space", Year: 1976, Genre: Action
  Title: "Eclipse", Year: 2004, Genre: Horror
  
  Adding movie: "A Simple Homework"
  ***VideoStore Database***
  Title: "A Simple Homework", Year: 1990, Genre: Comedy
  Title: "Compilation in Outer Space", Year: 1976, Genre: Action
  Title: "Eclipse", Year: 2004, Genre: Horror
  
  Adding customer: John Smith
  ***VideoStore Database***
  Title: "A Simple Homework", Year: 1990, Genre: Comedy
  Title: "Compilation in Outer Space", Year: 1976, Genre: Action
  Title: "Eclipse", Year: 2004, Genre: Horror
  Name: John Smith
  Address: 8th Street Bethesda CA
  No movies rented.
  
  Adding customer: Rose Peterson
  ***VideoStore Database***
  Title: "A Simple Homework", Year: 1990, Genre: Comedy
  Title: "Compilation in Outer Space", Year: 1976, Genre: Action
  Title: "Eclipse", Year: 2004, Genre: Horror
  Name: Rose Peterson
  Address: 101 Road RiverTown CA
  No movies rented.
  Name: John Smith
  Address: 8th Street Bethesda CA
  No movies rented.
  
  ***All movies***
  Title: "A Simple Homework", Year: 1990, Genre: Comedy
  Title: "Compilation in Outer Space", Year: 1976, Genre: Action
  Title: "Eclipse", Year: 2004, Genre: Horror
  
  ***All customers***
  Name: Rose Peterson
  Address: 101 Road RiverTown CA
  No movies rented.
  Name: John Smith
  Address: 8th Street Bethesda CA
  No movies rented.
  
  ***Looking for Horror movies***
  Title: "Eclipse", Year: 2004, Genre: Horror
  
  ***Looking for movies released on or after 1989
  Title: "A Simple Homework", Year: 1990, Genre: Comedy
  Title: "Eclipse", Year: 2004, Genre: Horror
  
  ***John Smith is renting the movie "Eclipse"
  Title: "A Simple Homework", Year: 1990, Genre: Comedy
  Title: "Compilation in Outer Space", Year: 1976, Genre: Action
  Title: "Eclipse", Year: 2004, Genre: Horror
  Name: Rose Peterson
  Address: 101 Road RiverTown CA
  No movies rented.
  Name: John Smith
  Address: 8th Street Bethesda CA
  Movies (rented): 
  Title: "Eclipse", Year: 2004, Genre: Horror
  
  ***Looking for the movie "Eclipse"
  Title: "Eclipse", Year: 2004, Genre: Horror (RENTED)
  
  ***John Smith is returning the movie "Eclipse"
  Title: "A Simple Homework", Year: 1990, Genre: Comedy
  Title: "Compilation in Outer Space", Year: 1976, Genre: Action
  Title: "Eclipse", Year: 2004, Genre: Horror
  Name: Rose Peterson
  Address: 101 Road RiverTown CA
  No movies rented.
  Name: John Smith
  Address: 8th Street Bethesda CA
  No movies rented.