Question

In this assignment, you will practice solving a problem using object-oriented programming and specifically, you will use the concept of object aggregation (i.e., has-a relationship between objects). You will implement a Java application, called MovieApplication that could be used in the movie industry. You are asked to implement three classes: Movie, Distributor, and MovieDriver. Each of these classes is described below.

The Movie class represents a movie and has the following attributes: name (of type String), directorsName (of type String), distributor (of type Distributor), and earnings (of type double).

Implement the following for the Movie class. Use the names exactly as given (where applicable) and in the other cases, use standard naming conventions.

• A constructor to initialize all instance variables, except earnings. A value for each instance variable will be passed as a parameter to the constructor with the exception of earnings, which will be set to zero. The parameters will be passed in the order name, directorsName, and distributor. The code will need to call addMovie() of

Distributor. Ensure that if the distributor cannot store the movie because the array is full, the distributor field will be null.

• A second constructor to initialize all instance variables, except earnings. A value for each instance variable will be passed as a parameter to the constructor with the exception of earnings and distributor, which will be set to zero and null, respectively. The parameters will be passed in the order name and directorsName. This constructor will use the one listed above to initialize the fields. It should do no assignments on its own.
• Getters for all instance variables.
• A setter method for each instance variable, except earnings. The setter for setDistributor() will need to call addMovie() of Distributor. (Ensure that if the distributor cannot store the movie because the array is full, the distributor field will be null.
• addToEarnings: a method than takes an amount (of type double) and adds that amount of money to the movie’s earnings.  
• equals: a method to test the equality of two movies. Two movies are considered to be equal if they have the same name. Ensure that your implementation satisfies all of the requirements of the equals method specified in the JDK documentation. (See a copy of Class Exercise 1 for a verbatim copy of these requirements.)
• hashCode: to be consistent with equals. See the JDK documentation copied in Class Exercise 1.
• toString: a method that returns a nicely formatted string description of the movie. All fields except distributor and the distributor’s name must be part of the string.
• Distributor Class:
• The Distributor class represents a distributor of movies. Every movie has at most one distributor and every distributor can distribute zero or more movies. (In this simplistic application, a distributor can distribute at most five movies.) The Distributor class has the following instance variables, named exactly as follows:
• name: a string that represents the distributor's name.
• address: a string that represents the distributor’s address.
• phone: a string that represents the distributor’s phone.
• movies: an instance variable of type array of Movie with length of 5.
• numberOfMovies: an instance variable that indicates the number of movies that have been added to the movies array.

• Implement the following for the Distributor class. Use the names exactly as given (where applicable) and in the other cases, use standard naming conventions.

• A constructor that takes as input only the distributor's name, address, and phone in that order, and creates the distributor by initializing the fields appropriately, and instantiating the array movies. Each Movie reference in the array will initially be null.
• Getters and setters for name, address, and phone.
• A getter for movies. Use Arrays.copyOf to trim the array to the exact number of movies and return the trimmed array. The statement

• return Arrays.copyOf(movies, numberOfMovies);

  does the trick.

• addMovie: a method that takes a single parameter of type Movie and returns a boolean. The method attempts to add the movie supplied as parameter to the array of Movie objects. If the number of movies is greater than or equal to the length of the array, the movie does not get added and the method returns false. Otherwise, the movie is added and the method returns true. Note that movies[0] must be filled before movies[1] and movies[1] must be filled before movies[2], etc. The field numberOfMovies is updated if necessary.
• equals: a method to test the equality of two distributors. Two distributors are considered to be equal if they have the same name. Ensure that your implementation satisfies all of the requirements of the equals method specified in the JDK documentation.
• hashCode: to be consistent with equals.
• toString: a method that returns a nicely formatted string description of the distributor. A properly formatted list of movies must be part of the returned string.

• Suppose Movie m stores a reference to Distributor object d. Then d stores a reference to

  m. While coding the toString() method, ensure that these mutual references do not result in infinite recursion.

         MovieDriver class:                                                                                                                      

  Your driver class should perform the following actions:

• Create at least 6 Movie objects with your choice of movie names and director names.
• Create at least 2 Distributor objects with your choice of names, addresses, and phone numbers.
• Make the same Distributor object (say, d) the distributor of 5 different movies. Attempt to add d as the distributor of a sixth movie. Demonstrate that this attempt does not crash the program, but the operation does not succeed. You must do this via the constructor of Movie as well as via the setDistributor() method.
• Exercise every method of both Movie and Distributor classes. Demonstrate that they work. For this, I recommend using the assert statement. Here is an example.

• Suppose you want to check the getter and setter for directorsName in the Movie class. For this, the code first sets the director’s name to some value, say, DIR25. Then you need to check that the getter returns the same name.

  One way of accomplishing this is to code as below.

       movie9.setDirectorsName("DIR25");

  System.out.println(movie9.getDirectorsName());

  While this approach works, testing is difficult. You have to remember while testing that

• you had set the director’s name to DIR25 and
• the getter returns DIR25, for which you need to examine the displays from the user.

•             This is very tedious, time-consuming, and highly error-prone.

              Instead, you can do the following.

  movie9.setDirectorsName("DIR25");

  assert movie9.getDirectorsName().equals("DIR25");

  The assert statement checks whether movie9.getDirectorsName().equals("DIR25")

    

      Is true. If not, the program crashes with an exception. So, in effect, we have a piece of code that checks itself. You save a lot of time with no additional effort.

Answer 1

Please find 3 classes, Enable assertions on your Environment. Program is Tested.

I have given one assertion, you can make as many as you want.

Distributer.java

package com.demos;

import java.util.Arrays;

public class Distributer {

   private String name;
   private String address;
   private String phone;
   private Movie[] movies;
   private int numberOfMovies;
  
   public Distributer(String name, String address, String phone) {
       super();
       this.name = name;
       this.address = address;
       this.phone = phone;
       movies=new Movie[5];
   }

   public String getName() {
       return name;
   }

   public void setName(String name) {
       this.name = name;
   }

   public String getAddress() {
       return address;
   }

   public void setAddress(String address) {
       this.address = address;
   }

   public String getPhone() {
       return phone;
   }

   public void setPhone(String phone) {
       this.phone = phone;
   }

   public Movie[] getMovies() {
       return Arrays.copyOf(movies,numberOfMovies);
   }
  
   //added
   public void setMovies(Movie[] movies) {
       this.movies = movies;
   }

   public boolean addMovie(Movie movie) {
       if(numberOfMovies>=movies.length)
           return false;
       else {
           movies[numberOfMovies++]=new Movie(movie.getName(), movie.getDirectorsName());
           return true;
       }
   }

   @Override
   public int hashCode() {
       final int prime = 31;
       int result = 1;
       result = prime * result + ((name == null) ? 0 : name.hashCode());
       return result;
   }

   @Override
   public boolean equals(Object obj) {
       if (this == obj)
           return true;
       if (obj == null)
           return false;
       if (getClass() != obj.getClass())
           return false;
       Distributer other = (Distributer) obj;
       if (name == null) {
           if (other.name != null)
               return false;
       } else if (!name.equals(other.name))
           return false;
       return true;
   }

   @Override
   public String toString() {
       return "Distributer [name=" + name + ", address=" + address + ", phone=" + phone + ", movies="
               + Arrays.toString(movies) + ", numberOfMovies=" + numberOfMovies + "]";
   }

}

Movie.java

package com.demos;

public class Movie {

   private String name;
   private String directorsName;  
   private Distributer distributer;
   private double earnings;
  
   public Movie(String name, String directorsName, Distributer distributer) {
       super();
       this.name = name;
       this.directorsName = directorsName;
       this.distributer = distributer;
   }

   public Movie(String name, String directorsName) {
       super();
       this.name = name;
       this.directorsName = directorsName;
   }

  
  
   public String getName() {
       return name;
   }

   public void setName(String name) {
       this.name = name;
   }

   public String getDirectorsName() {
       return directorsName;
   }

   public void setDirectorsName(String directorsName) {
       this.directorsName = directorsName;
   }

   public Distributer getDistributer() {
       return distributer;
   }

   public void setDistributer(Distributer distributer) {
       this.distributer = distributer;
       System.out.println(this.distributer.addMovie(this));
   }

   public double getEarnings() {
       return earnings;
   }
  
   public void addToEarnings(double amount) {
       this.earnings+=amount;
   }

   @Override
   public int hashCode() {
       final int prime = 31;
       int result = 1;
       result = prime * result + ((name == null) ? 0 : name.hashCode());
       return result;
   }

   @Override
   public boolean equals(Object obj) {
       if (this == obj)
           return true;
       if (obj == null)
           return false;
       if (getClass() != obj.getClass())
           return false;
       Movie other = (Movie) obj;
       if (name == null) {
           if (other.name != null)
               return false;
       } else if (!name.equals(other.name))
           return false;
       return true;
   }

   @Override
   public String toString() {
       return "Movie [name=" + name + ", directorsName=" + directorsName + ", distributer=" + distributer
               + ", earnings=" + earnings + "]";
}
}

MovieDriver.java

package com.demos;

public class MovieDriver {

   public static void main(String args[]) {
       Movie m1=new Movie("Krish2","Rakesh Roshan");
       Movie m2=new Movie("Welcome Back","Anees");
       Movie m3=new Movie("KHNPH", "Rakesh");
       Movie m4=new Movie("Holiday", "AR Murogaddos");
       Movie m5=new Movie("Main Tera Hero ", "David");
       Movie m6=new Movie("Judawaa2", "David"); // when you run you will find false for this
      
       Distributer d1=new Distributer("pratik", "VPeast", "6626599930");
       Distributer d2=new Distributer("ayush", "Mumbai", "993026130340");
      
       m1.setDistributer(d1);
       m2.setDistributer(d1);
       m3.setDistributer(d1);
       m4.setDistributer(d1);
       m5.setDistributer(d1);
       m6.setDistributer(d1);
      
       m2.setDirectorsName("Annes Bazmee"); //set name of director with surname
      
       System.out.println(m1);
       System.out.println(m2);

       assert (m2.getDirectorsName().equals("Annes")):"Director name is not Annes";

      
   }
}

Thanks