Question

Write the code for the Song class. 1. Instance variables: title:String, lyrics:String, numAwards:int 2. For the 2-arg constructor (parameters are title and lyrics), use the following default value: - numAwards: 3 3. Create the 3-argument constructor. 4. No additionalconstructors. 5. Generate all getters and setters for instance variables 6. toString: Return a nicely formatted string describing this object 7. toSummary: This instance method will return a String that contains up to the first 10 characters of the lyrics. Be sure to handle the case where the lyrics are shorter than 10 chars. No explicit parameters. 8. isGoodSong: This instance method with no parameters will return true if BOTH of the following are true: - Number of awards > 3 AND - Title starts with “Fun” or “Dance” (case insensitive) 9. countHappy: This instance method with no parameters will return the number of times "happy" appears anywhere in the lyrics. This comparison is case insensitive. Part 2: SongTester 10. Download the starter file for SongTester.java from the D2L dropbox. 11. Run the existing SongTester.java to test out your countHappy and isWinningSong methods. Fix any problems indicated by these test cases 12. sumAwards: In SongTester.java, create a static method called sumAwards. It should have an ArrayList as a parameter. The method should return the total number of awards (an int) all of the songs in the list have won. 13. In the main method: - Create at least 5 Song objects - Place the objects in an ArrayList of Songs named songAL. - Test your toSummary method using the songAL ArrayList. Fix if needed. - For the song at index 1, replace the lyrics with “Na-na-na-boo-boo”. - Call the sumAwards method using the songAL as a parameter. SOP the result.

This is the Tester method:

public class SongTester
{

/**
* ****DO NOT MODIFY this method****
* This method returns the percentage of test cases
* that the isGoodSong method has succesfully passed
* @return percentage of correct test cases
*/
public static double testisGoodSong()
{
Song song1 = new Song("", "");
int countCorrect = 0;

song1.setNumAwards(5);
song1.setTitle("Dance revolution");
if ( song1.isGoodSong())
{
countCorrect++;
}
else
{
System.err.println("isGoodSong case1 failed");
}

song1.setNumAwards(1);
song1.setTitle("Fun in the sun");
if ( !song1.isGoodSong())
{
countCorrect++;
}
else
{
System.err.println("isGoodSong case2 failed");
}

song1.setNumAwards(0);
song1.setTitle("Fun in the sun");
if ( !song1.isGoodSong())
{
countCorrect++;
}
else
{
System.err.println("isGoodSong case3 failed");
}

song1.setNumAwards(2);
song1.setTitle("Not winning");
if ( !song1.isGoodSong())
{
countCorrect++;
}
else
{
System.err.println("isGoodSong case4 failed");
}
return countCorrect/4.0*100;
}

/**
* ****DO NOT MODIFY this method****
* This method returns the percentage of test cases
* that the countHappy method has succesfully passed
* @return percentage of correct test cases
*/
public static double testcountHappy()
{
Song song1 = new Song("Default", "Short one");
int countCorrect = 0;

if ( song1.countHappy() == 0)
{
countCorrect++;
}
else
{
System.err.println("countHappy case1 failed");
}

song1.setLyrics("Happy haPPy");
if ( song1.countHappy() == 2)
{
countCorrect++;
}
else
{
System.err.println("countHappy case2 failed");
}

song1.setLyrics("Lots of lyrics. Example of long lyric with HAPPY!!!!!! in middle");
if ( song1.countHappy() == 1)
{
countCorrect++;
}
else
{
System.err.println("countHappy case3 failed");
}
song1.setLyrics("My happy song. My happyhappyhappy song. Is happily happy song. happy");
if ( song1.countHappy() == 6)
{
countCorrect++;
}
else
{
System.err.println("countHappy case4 failed");
}
return countCorrect/4.0*100;
}

public static void main(String[] args)
{
System.out.println("Percent correct for isGoodSong: " + testisGoodSong() );
System.out.println("Percent correct for countHappy: " + testcountHappy() );

}
}

Answer 1

Below is the code for Part 1. It is well explained inside the code using comments.

//Song.java

// Song class
class Song {

    // Instance variables
    private String title;       // title of the Song
    private String lyrics;      // lyrics of the Song
    private int numAwards;      // number of awards

    // Constructor
    public Song(String title, String lyrics) {
        this.title = title;
        this.lyrics = lyrics;
        numAwards = 3;
    }

    // constructor
    public Song(String title, String lyrics, int numAwards) {
        this.title = title;
        this.lyrics = lyrics;
        this.numAwards = numAwards;
    }

    // returns the title
    public String getTitle() {
        return title;
    }

    // returns the lyrics
    public String getLyrics() {
        return lyrics;
    }

    // returns the number of awards
    public int getNumAwards() {
        return numAwards;
    }

    // sets the title
    public void setTitle(String title) {
        this.title = title;
    }

    // sets the lyrics
    public void setLyrics(String lyrics) {
        this.lyrics = lyrics;
    }

    // sets the number of awards
    public void setNumAwards(int numAwards) {
        this.numAwards = numAwards;
    }

    // returns the Song object in String format
    @Override
    public String toString() {
        return "Song, Title: " + title + "\nLyrics: " + lyrics + ". It has won " + numAwards + " awards.";
    }

    // this method will return a String that contains up to the first 10 characters of the lyrics
    public String toSummary() {
        // is length of lyrics is more than 10, return first 10 characters
        if (lyrics.length() > 10) {
            return lyrics.substring(0, 10);
        } else {
            return lyrics;
        }
    }

    // returns true if Number of awards > 3 AND - Title starts with "Fun" or "Dance"
    public boolean isGoodSong() {
        return numAwards > 3 && (title.toLowerCase().startsWith("fun") || title.toLowerCase().startsWith("dance"));
    }

    // this method will return the number of times "happy" appears anywhere in the lyrics
    public int countHappy() {
        int count = 0; // to store happy countts
        int pos = 0; // to store position to check for happy in lyrics
        String lyricsSmall = lyrics.toLowerCase(); // lyrics in lower case to compare with happy
        int happyLength = 5;    // length of word happy

        // keep checking until it doesn't find happy in lyrics
        while (pos != -1) {
            // get position of happy
            pos = lyricsSmall.indexOf("happy", pos);
          
            // if found happy
            if(pos != -1){
                // increase the counter
                count += 1;
              
                // increase the position
                pos += happyLength;
            }
        }

        // return the happy count
        return count;
    }
}

Below is the output with the given main class:

Below is the code for Part 2, changes are highlighted in bold:

// SongTester.java
import java.util.ArrayList;

public class SongTester {

    /**
     * ****DO NOT MODIFY this method**** This method returns the percentage of
     * test cases that the isGoodSong method has succesfully passed
     *
     * @return percentage of correct test cases
     */
    public static double testisGoodSong() {
        Song song1 = new Song("", "");
        int countCorrect = 0;
      
        song1.setNumAwards(5);
        song1.setTitle("Dance revolution");
        if (song1.isGoodSong()) {
            countCorrect++;
        } else {
            System.err.println("isGoodSong case1 failed");
        }
      
        song1.setNumAwards(1);
        song1.setTitle("Fun in the sun");
        if (!song1.isGoodSong()) {
            countCorrect++;
        } else {
            System.err.println("isGoodSong case2 failed");
        }
      
        song1.setNumAwards(0);
        song1.setTitle("Fun in the sun");
        if (!song1.isGoodSong()) {
            countCorrect++;
        } else {
            System.err.println("isGoodSong case3 failed");
        }
      
        song1.setNumAwards(2);
        song1.setTitle("Not winning");
        if (!song1.isGoodSong()) {
            countCorrect++;
        } else {
            System.err.println("isGoodSong case4 failed");
        }
        return countCorrect / 4.0 * 100;
    }

    /**
     * ****DO NOT MODIFY this method**** This method returns the percentage of
     * test cases that the countHappy method has succesfully passed
     *
     * @return percentage of correct test cases
     */
    public static double testcountHappy() {
        Song song1 = new Song("Default", "Short one");
        int countCorrect = 0;
      
        if (song1.countHappy() == 0) {
            countCorrect++;
        } else {
            System.err.println("countHappy case1 failed");
        }
      
        song1.setLyrics("Happy haPPy");
        if (song1.countHappy() == 2) {
            countCorrect++;
        } else {
            System.err.println("countHappy case2 failed");
        }
      
        song1.setLyrics("Lots of lyrics. Example of long lyric with HAPPY!!!!!! in middle");
        if (song1.countHappy() == 1) {
            countCorrect++;
        } else {
            System.err.println("countHappy case3 failed");
        }
        song1.setLyrics("My happy song. My happyhappyhappy song. Is happily happy song. happy");
        if (song1.countHappy() == 6) {
            countCorrect++;
          
        } else {
            System.err.println("countHappy case4 failed");
        }

        // create ArrayList of songs
        ArrayList<Song> songAL = new ArrayList<>();

        // add 5 song objects
        songAL.add(new Song("Skinny Love", "Come on skinny love just last the year. Pour a little salt we were never here", 2));
        songAL.add(new Song("Beautiful in white", "Not sure if you know this But when we first met I got so nervous", 1));
        songAL.add(new Song("In My Feelings", "Trap, TrapMoneyBenny Trap, TrapMoneyBenny Trap, TrapMoneyBenny", 5));
        songAL.add(new Song("Mercy", "Why you gotta show up lookin so good"));
        songAL.add(new Song("Girls like you", "Spent 24 hours, I need more hours with you", 3));

        // display Summary
        for (Song song : songAL) {
            System.out.println(song.toSummary());
        }

        // For the song at index 1, replace the lyrics with “Na-na-na-boo-boo”.
        Song song = songAL.get(1);
        song.setLyrics("Na-na-na-boo-boo");
        songAL.set(1, song);
      
        // display songs list after update
        System.out.println("\nAfter updating song list:");
        // display Summary
        for (Song s : songAL) {
            System.out.println(s.toSummary());
        }
      
        // call sum awards and display the total awards
        System.out.println("\nTotal Awards: " + sumAwards(songAL));
      
        return countCorrect / 4.0 * 100;
    }
  
    public static void main(String[] args) {
        System.out.println("Percent correct for isGoodSong: " + testisGoodSong());
        System.out.println("Percent correct for countHappy: " + testcountHappy());
      
    }

    // returns the total number of awards all of the songs in the list have won
    public static int sumAwards(ArrayList<Song> songs) {
        int total = 0;      // to store total awards count

        // iterate through all songs and count awards
        for (Song song : songs) {
            total += song.getNumAwards();
        }

        // return total awards
        return total;
    }
}

Below is the sample output:

This completes the requirement. Let me know if you have any questions.

Thanks!