CS111 - Song - Solved

Suppose you want to have an application to keep track of all the songs you have. The first step is to define a class that represents a Song 
and all the information you want to store about it. Write your code in the file Song.java to implement a class called Song with the following 
private attributes (use the exact names):

name: a String for the name of the song;
year: an integer for the year the song was released;
numberOfWriters: an integer to store the number of the song’s composers;
writers: an array of Strings to store the name of the song's composers. A song can have a maximum of 50 composers;
rating: an integer value ranging from 1 (horrible) to 5 (the best song ever).


Your class should also contain the following methods (use the same signature):
public Song(String name): that takes as an argument the song's name;

public void setName(String name): updates song's name attribute;

public String getName(): returns song's name attribute;

public void setYear(int year): updates song's year attribute;

public int getYear(): returns song's year attribute;

public void setRating(int rating): update song's rating attribute;

public int getRating(): returns song's rating attribute;

public void addWriter(String writerName): receives a String with the writer’s name as a parameter and inserts the String into the writer array at the 
                                          first empty position; update numberOfWriters to reflect the new number of writers;
                                          
public String[] getWriters(): returns the writers array attribute;

public int getNumberOfWriters():returns the value of numberOfWriters attribute;

public String getWriterAtIndex(int index): returns the writer’s name at that index. Use 0 based indexing where an index of 0 is the first name. It should 
                                           return null if there is no writer at that index;
                                           
public String toString(): returns the string representation of this song with the song's name, year, and rating. Output in the format "name, year, rating";

public boolean equals(Object other): returns true if this object is the same as other object. Two objects are equal if they have the same name, 
                                     the same writers/composers, and were released at the same year. Assume the ordering of writers might not be the same and 
                                     no duplicate writer name exists in either song.
                                     
public int compareTo (Song other): return 0 if this song's name is lexicographically equal to other song's name; Return a negative number, say -1, if this 
                                   song's name is less than the other song's name lexicographically; Return a postive number, say 1, if this song's name is greater 
                                   than the other song's name lexicographically.