Question

Write an application that instantiates five Recording objects and prompts the user for values for the data fields. Then prompt the user to enter which field the Recordings should be sorted by—(S)ong title, (A)rtist, or playing (T)ime. Perform the requested sort procedure, and display the Recording objects. Validations:

Answer 1

Answer:

Here is the JAVA application

Recording.java:

class Recording {  //class name

String title;  //String type variable to store the title of the song

String artist;  //String type variable to store the artist name of the song

int playingTime;  //int type variable to store the playing time of the song in seconds  

public String getTitle() {  //accessor method to get the title of the song

   return title; }   //returns the current title of song

public void setTitle(String title) {  //mutator method to set the title of song

   this.title = title;  }   // sets the title of song

public String getArtist() {  //accessor method to get the artist name of the song

  return artist; }   //returns the current artist name of song

public void setArtist(String artist) {  //mutator method to set the artist name of song

  this.artist = artist; }   //sets the artist name

public int getPlayingTime() {  //accessor method to get the playing time of the song

   return playingTime; } /  /returns the playing time of song

public void setPlayingTime(int pt) {  //mutator method to set the playing time of song

   this.playingTime = pt; }   //sets the playing time of song

public Recording(String title, String artist, int playingTime) {  //parmeterized constructor of Recording class that takes title, artist and playingTime as parameters

this.title = title;  

this.artist = artist;

this.playingTime = playingTime;  }  }

Explanation:

Here is the Main class:  

import java.util.Scanner;   //to accept input from user

public class Main {  

public static void main(String[] args) {  // start of main function

 Recording[] song = new Recording[5];  //creates object of Recording class named song to instantiate five Recording objects

 Scanner input = new Scanner(System.in);  //creates Scanner class object named input

 int i = 0;  // declare i and initialize it to -

 for (i = 0; i < song.length; i++) {  //iterates through the list of song

  int j = i + 1;  

  System.out.print("Enter the title of song " + j + ": ");  //prompts user to enter the title of song

 String title = input.nextLine();   //reads the title string from user

 System.out.print("Enter the artist of song " + j + ": ");  //prompts user to enter the artist of song

 String artist = input.nextLine();   //reads the artist string from user

System.out.print("Enter the playing time of song " + j + " in seconds: ");   //prompts user to enter the playing time of song

 String playtime = input.nextLine();  //reads the playing time string value from user

 int playingTime = Integer.parseInt(playtime);   // converts String value of playtime to integer

 song[i] = new Recording(title, artist, playingTime); }   //calls constructor of Recording class by passing title, artist and playingTime to it  

 int sort;  // for choosing which field to sort

do {  //continues to ask user to enter which field the Recordings should be sorted by

System.out.println("How should these songs be sorted? 1 for title 2 for artist 3 for playing time");  

sort = input.nextInt();  //reads user choice to sort

       if (sort > 0 && sort < 4) {  //to check if user enters a valid choice

 int a, b;  

 int max = song.length - 1;  

for (a = 0; a < max; a++) {  //iterates through the length of the song list setting an index variable a

      for (b = 0; b < max; b++) {    //iterates through the length of the song list setting an index variable b

  int c = b + 1;

     if (sort == 1) {  //if the user selects title field

       if (song[b].getTitle().compareTo(song[c].getTitle()) > 0) {  // compares title of one song with the song that comes after it

   Recording temp = song[b];  //sorts the titles using bubble sort by ordering each title to the immediate next and swapping them if they are not sorted already

   song[b] = song[c];

   song[c] = temp; } }  

   else if (sort == 2) {    //if the user selects artist field

  if (song[b].getArtist().compareTo(song[c].getArtist()) > 0) {  // compares artist of one song with the song artist  that comes after it

//sorts the artists using bubble sort by ordering each title to the immediate next and swapping them if they are not sorted already

     Recording temp = song[b];

     song[b] = song[c];

     song[c] = temp;  }  }  

   else if (sort == 3) {   //if the user selects playing time field

  if (song[b].getPlayingTime() > song[c].getPlayingTime()) {

/* compares artist of one song with the song artist  that comes after it sorts the artists using bubble sort by ordering each title to the immediate next and swapping them if they are not sorted already */

       Recording temp = song[b];

        song[b] = song[c];

         song[c] = temp;  } } } }  }  

             else {  //if user enters any invalid choice

 System.out.println("Invalid choice! Enter right choice"); }        

       } while (sort < 1 || sort > 3);  //keeps asking user to enter which field the recording to sort by until the value of sort in range of 1 to 3

for (i = 0; i < song.length; i++) {  //displays the sorted song list according to selected field

System.out.println("Song: Title: " + song[i].getTitle() + ". Artist: " + song[i].getArtist() + ". Playing time: " + song[i].getPlayingTime() + " seconds.");  }

input.close();  }  }

The output of the program is attached.