Question

is there anyway you can modify the code so that when i run it i can see all the song when i click the select button all the songs in the songList.txt file can be shown

song.java

package proj2;

public class Song
{
private String name;
private String itemCode;
private String description;
private String artist;
private String album;
private String price;

Song(String name, String itemCode, String description, String artist, String album, String price)
{
this.name = name;
this.itemCode = itemCode;
this.description = description;
this.artist = artist;
this.album = album;
this.price = price;
}

public String getName()
{
return name;
}
/**
*set Name assigns the name to this instance of name
**/
public void setName(String name)
{
this.name = name;
}
/**
* Method getItemCode gets the ItemCode of the song or album
* @return returns the ItemCode of the song or album
**/
public String getItemCode()
{
return itemCode;
}

/**
* Method setItemCode assigns the ItemCode to this instance of song or album
**/
public void setItemCode(String itemCode)
{
this.itemCode = itemCode;
}
/**
* Method getDescription gets the ItemCode of the song or album
* @return returns the description of the song or album
**/
public String getDescription()
{
return description;
}
/**
* Method setDescription assigns a description to this instance of description
**/
public void setDescription(String description)
{
this.description = description;
}
/**
* Method getArtist gets the name of Artist or Artists of the song or album
* @return returns the name of Artist or Artists of the instance of album
**/
public String getArtist()
{
return artist;
}

/**
* Method setArtist assigns the name of Artist or Artists to this instance of Artist
**/
public void setArtist(String artist)
{
this.artist = artist;
}

/**
* Method getAlbum gets the album name which the song came from
* @return returns a name of the album the song came from if there is an album
**/
public String getAlbum()
{
return album;
}

public void setAlbum(String album)
{
this.album = album;
}

public String getPrice()
{
return price;
}

public void setPrice(String price)
{
this.price = price;
}

}

songdatabase.java:

package proj2;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;
import javax.swing.*;
public class SongDatabase extends JFrame implements ActionListener, ItemListener
{
private JButton addButton, editButton, deleteButton, acceptButton, cancelButton, exitButton;// saveButton;
private JLabel lbSelectSong, lbSongCode, lbSongDescription, lbSongArtist, lbSongAlbum, lbSongPrice;
private JTextField tfSongCode, tfSongDescription, tfSongArtist, tfSongAlbum, tfSongPrice;
private JComboBox cbSelectSong;

ArrayList<Song> songList;
boolean flag = false;

public static void main(String[] args)
{
new SongDatabase();
}

public void readFile()
{
String filename = "songList.txt";
try
{
FileReader inputFile = new FileReader(filename);
  
Scanner parser = new Scanner(inputFile);
  
while(parser.hasNextLine())
{
String lineInfo = parser.nextLine();
  
String[] data = lineInfo.split(","); //Looking for a comma as the delimiter to parse the data
  
String name = data[0];
String itemCode = data[1];
String description = data[2];
String artist = data[3];
String album = data[4];
String price = data[5];
  
Song song = new Song(name, itemCode, description, artist, album, price);
songList.add(song);
}
inputFile.close();
}
catch (IOException e)
{
JOptionPane.showMessageDialog(null, "File does not exist", "Note", JOptionPane.INFORMATION_MESSAGE);
}
}

public SongDatabase()
{
songList = new ArrayList<Song>();

readFile();
arrangePosition();
Container con = this.getContentPane();
con.setLayout(null);

lbSelectSong = new JLabel("Select Song");
lbSelectSong.setBounds(100,30,120,25);
con.add(lbSelectSong);

cbSelectSong = new JComboBox();

for ( int i = 0; i < songList.size(); i++)
{
Song song = songList.get(i);
  
cbSelectSong.addItem(song.getName());
}

//*******add Select Song drop down Label and Field ***//
cbSelectSong.setBounds (200,30,200,25);
cbSelectSong.addItemListener (this);
add(cbSelectSong);

//*******add Item Code Label and Field ***********//
lbSongCode = new JLabel ("Item Code");
lbSongCode.setBounds (100,70,120,25);
con.add (lbSongCode);

tfSongCode = new JTextField(20);
tfSongCode.setBounds(200,70,200,25);
con.add(tfSongCode);
  
//*******add Description Label and Field ***********//
lbSongDescription = new JLabel("Description");
lbSongDescription.setBounds(100,110,120,25);
con.add(lbSongDescription);

tfSongDescription = new JTextField(20);
tfSongDescription.setBounds(200,110,200,25);
con.add(tfSongDescription);

//*******add Artist Label and Field ***********//
lbSongArtist = new JLabel("Artist");
lbSongArtist.setBounds(100,150,120,25);
con.add(lbSongArtist);

tfSongArtist = new JTextField(20);
tfSongArtist.setBounds(200,150,200,25);
con.add(tfSongArtist);
//*******add Album Label and Field ***********//
lbSongAlbum = new JLabel("Album");
lbSongAlbum.setBounds(100,190,120,25);
con.add(lbSongAlbum);

tfSongAlbum = new JTextField(20);
tfSongAlbum.setBounds(200,190,200,25);
con.add(tfSongAlbum);
//*******add Price Label and Field ***********//
lbSongPrice = new JLabel("Price");
lbSongPrice.setBounds(100,230,120,25);
con.add(lbSongPrice);

tfSongPrice = new JTextField(20);
tfSongPrice.setBounds(200,230,200,25);
con.add(tfSongPrice);
//**********************************************//
//*******add "ADD" Button ***********//
addButton=new JButton("Add");
addButton.setBounds(10,310,90,30);
addButton.addActionListener(this);
con.add(addButton);

//*******add "EDIT" Button ***********//
editButton=new JButton("Edit");
editButton.setBounds(110,310,80,30);
editButton.addActionListener(this);
con.add(editButton);

//*******add "DELETE" Button ***********//
deleteButton=new JButton("Delete");
deleteButton.setBounds(210,310,80,30);
deleteButton.addActionListener(this);
con.add(deleteButton);

//*******add "ACCEPT" Button ***********//
acceptButton=new JButton("Accept");
acceptButton.setBounds(310,310,80,30);
acceptButton.addActionListener(this);
con.add(acceptButton);
//*******add "CANCEL" Button ***********//
cancelButton=new JButton("Cancel");
cancelButton.setBounds(410,310,80,30);
cancelButton.addActionListener(this);
con.add(cancelButton);

//*******add " " Button ***********//
exitButton=new JButton("Exit");
exitButton.setBounds(170,370,80,30);
exitButton.addActionListener(this);
con.add(exitButton);

//*******add "SAVE" Button ***********//
// saveButton=new JButton("SAVE");
// saveButton.setBounds(270,370,80,30);
// saveButton.addActionListener(this);
// con.add(saveButton);

//********************************************
if(songList.size() > 0)
{
Song song = songList.get(0);
tfSongCode.setText(song.getItemCode());
tfSongDescription.setText(song.getDescription());
tfSongArtist.setText(song.getArtist());
tfSongAlbum.setText(song.getAlbum());
tfSongPrice.setText(song.getPrice());
}

tfSongCode.setEnabled(false); //the item Code field is disabled
tfSongDescription.setEnabled(false); //the Description field is disabled
tfSongArtist.setEnabled(false); //the Artist field is disabled
tfSongAlbum.setEnabled(false); //the Album field is disabled
tfSongPrice.setEnabled(false); //the Price field is disabled
  
addButton.setEnabled(true); // set the ADD button to be enabled
editButton.setEnabled(true); // set the EDIT button to be enabled
deleteButton.setEnabled(true); // set the DELETE button to be enabled
acceptButton.setEnabled(false); //the ACCEPT & CANCEL BUTTONS ARE DISABLED
cancelButton.setEnabled(false); //the ACCEPT & CANCEL BUTTONS ARE DISABLED
exitButton.setEnabled(true); // set the EXIT button to be enabled
// saveButton.setEnabled(true); // set the SAVE button to be enabled
  
setTitle("Song Database");
setSize(500,500);
setVisible(true);
setResizable(false);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
public void arrangePosition()
{
Toolkit tookit = Toolkit.getDefaultToolkit() ;

Dimension scDimentions = tookit.getScreenSize() ;

int scHeight = (int) scDimentions.getHeight() ;

int scWidth = (int) scDimentions.getWidth() ;

int x = ( scWidth - 500) / 2 ;

int y = ( scHeight - 600 ) / 2;

setLocation(x,y);
}

@Override
public void actionPerformed(ActionEvent e)
{

if(e.getSource() == addButton)
{
Toolkit.getDefaultToolkit().beep();
flag = false;
editButton.setEnabled(false); // set the EDIT button to be disabled
deleteButton.setEnabled(false); // set the DELETE button to disabled
acceptButton.setEnabled(true); // set the ACCEPT button to be enabled
cancelButton.setEnabled(true); // set the CANCEL button to be enabled

tfSongCode.setText("");
tfSongDescription.setText("");
tfSongArtist.setText("");
tfSongAlbum.setText("");
tfSongPrice.setText("");

tfSongCode.setEnabled(true); //the item CODE field is enabled
tfSongDescription.setEnabled(true); //the item DESCRIPTION field is enabled
tfSongArtist.setEnabled(true); //the item ARTIST field is enabled
tfSongAlbum.setEnabled(true); //the item ALBUM field is enabled
tfSongPrice.setEnabled(true); //the item PRICE field is enabled

}
if(e.getSource() == editButton)
{
Toolkit.getDefaultToolkit().beep();
flag = true;
tfSongCode.setEnabled(false); //the item CODE field is disabled
tfSongDescription.setEnabled(true); //the item DESCRIPTION field is enabled
tfSongArtist.setEnabled(true); //the item ARTIST field is enabled
tfSongAlbum.setEnabled(false); //the item ALBUM field is disabled
tfSongPrice.setEnabled(true); //the item PRICE field is enabled

addButton.setEnabled(false); // set the ADD button to be disabled
editButton.setEnabled(false); // set the EDIT button to be disabled
deleteButton.setEnabled(false); // set the DELETE button to disabled
acceptButton.setEnabled(true); // set the ACCEPT button to be enabled
cancelButton.setEnabled(true); // set the ACCEPT button to be enabled
exitButton.setEnabled(true); // set the CANCEL button to be enabled
// saveButton.setEnabled(true); // set the SAVE button to be enabled

tfSongDescription.setText("");
tfSongArtist.setText("");
tfSongPrice.setText("");
  
if(tfSongDescription.getText().length() == 0)
{
JOptionPane.showMessageDialog(null, "Enter song description", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}
if(tfSongArtist.getText().length() == 0)
{
JOptionPane.showMessageDialog(null, "Enter song artist", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}
if(tfSongPrice.getText().length() == 0)
{
JOptionPane.showMessageDialog(null, "Enter song price", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}
}

if(e.getSource() == deleteButton)
{
  
}
if(e.getSource() == acceptButton)
{

if(tfSongCode.getText().length() == 0)
{
JOptionPane.showMessageDialog(null, "Enter song code", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}
  
if(tfSongDescription.getText().length() == 0)
{
JOptionPane.showMessageDialog(null, "Enter song description", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}

if(tfSongArtist.getText().length() == 0)
{
JOptionPane.showMessageDialog(null, "Enter song artist", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}

if(tfSongAlbum.getText().length() == 0)
{
JOptionPane.showMessageDialog(null, "Enter song album", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}
  
if(tfSongPrice.getText().length() == 0)
{
JOptionPane.showMessageDialog(null, "Enter song price", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}

String name = tfSongDescription.getText();
String itemCode = tfSongCode.getText();
String description = tfSongDescription.getText();
String artist = tfSongArtist.getText();
String album = tfSongAlbum.getText();
String price = tfSongPrice.getText();

if(!flag)
{
Song song = new Song(name, itemCode, description, artist, album, price);

songList.add(song);
  
cbSelectSong.addItem(song.getName());
  
JOptionPane.showMessageDialog(null, "New song added into list", "Note", JOptionPane.INFORMATION_MESSAGE);
}
else
{
Song song = new Song(name, itemCode, description, artist, album, price);

int index = cbSelectSong.getSelectedIndex();
  
songList.set(index, song);
  
cbSelectSong.remove(index);

cbSelectSong.addItem(name);
  
JOptionPane.showMessageDialog(null, "new song updated successfully", "Note", JOptionPane.INFORMATION_MESSAGE);
}
}
if(e.getSource() == cancelButton)
{

if(songList.size() > 0)
{
cbSelectSong.setSelectedIndex(0);

Song song = songList.get(0);

tfSongCode.setText(song.getItemCode());
tfSongDescription.setText(song.getDescription());
tfSongArtist.setText(song.getArtist());
tfSongAlbum.setText(song.getAlbum());
tfSongPrice.setText(song.getPrice());
}

tfSongCode.setEnabled(false); //the item CODE field is disabled
tfSongDescription.setEnabled(false); //the item DESCRIPTION field is disabled
tfSongArtist.setEnabled(false); //the item ARTIST field is disabled
tfSongAlbum.setEnabled(false); //the item ALBUM field is disabled
tfSongPrice.setEnabled(false); //the item PRICE field is disabled

addButton.setEnabled(true); // set the ADD button to be enabled
editButton.setEnabled(true); // set the EDIT button to be enabled
deleteButton.setEnabled(true); // set the DELETE button to be enabled
acceptButton.setEnabled(false); // set the ACCEPT button to be disabled
cancelButton.setEnabled(false); // set the CANCEL button to be disabled
exitButton.setEnabled(true); // set the EXIT button to be enabled
// saveButton.setEnabled(true); // set the SAVE button to be enabled

}

if(e.getSource() == exitButton)
{
Toolkit.getDefaultToolkit().beep();
  
System.exit(0);
}

}

@Override
public void itemStateChanged(ItemEvent ie)
{
int index = cbSelectSong.getSelectedIndex();

Song song = songList.get(index);

tfSongCode.setText(song.getItemCode());
tfSongDescription.setText(song.getDescription());
tfSongArtist.setText(song.getArtist());
tfSongAlbum.setText(song.getAlbum());
tfSongPrice.setText(song.getPrice());

tfSongCode.setEnabled(false); //the item CODE field is disabled
tfSongDescription.setEnabled(false); //the item DESCRIPTION field is disabled
tfSongArtist.setEnabled(false); //the item ARTIST field is disabled
tfSongAlbum.setEnabled(false); //the item ALBUM field is disabled
tfSongPrice.setEnabled(false); //the item PRICE field is disabled
}
}

songList.txt:

Yellow Submarine, BT012, Yellow Submarine, Ringo Starr, The Beatles, 12.99
Yellow Submarine, BT015, Yellow Submarine, The Beatles, Beatles Greatest Hits 1, 10.99
New York New York, BT016, New York New York, Frank Sinatra, Trilogy Past Present Future, 9.99
Viva la Vida, BT017, Viva la Vida, Coldplay, Viva la Vida, 12.99
Unchained Melody, BT018, Unchained Melody, Billy Haliday, The Best of the Righteous Brothers, 13.99
Blue 1, BT019, Yellow Submarine, The Beatles, Beatles 1, 1.99
Blue 1, BT020, Yellow Submarine, The Beatles, Beatles 1, 1.99
Yellow Submarine, BT013, Yellow Submarine, The Beatles, Beatles Greatest Hits 1, 1.99
Yellow Submarine, BT014, Yellow Submarine, The Beatles, Beatles Greatest Hits 1, 1.99

Answer 1

JCOmboBox is unable to handle duplicate names, so adding a unique value in the name works fine. Changes are being made at line 72.
So now when you select any value from dropdown, you get results relating to that song only.

package com.HomeworkLib;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;
import javax.swing.*;

public class SongDatabase extends JFrame implements ActionListener, ItemListener {
private JButton addButton, editButton, deleteButton, acceptButton, cancelButton, exitButton;// saveButton;
private JLabel lbSelectSong, lbSongCode, lbSongDescription, lbSongArtist, lbSongAlbum, lbSongPrice;
private JTextField tfSongCode, tfSongDescription, tfSongArtist, tfSongAlbum, tfSongPrice;
private JComboBox cbSelectSong;

ArrayList<Song> songList;
boolean flag = false;

public static void main(String[] args) {
new SongDatabase();
}

public void readFile() {
String filename = "songList.txt";
try {
FileReader inputFile = new FileReader(filename);

Scanner parser = new Scanner(inputFile);

while (parser.hasNextLine()) {
String lineInfo = parser.nextLine();

String[] data = lineInfo.split(","); //Looking for a comma as the delimiter to parse the data

String name = data[0];
String itemCode = data[1];
String description = data[2];
String artist = data[3];
String album = data[4];
String price = data[5];

Song song = new Song(name, itemCode, description, artist, album, price);
songList.add(song);
}
inputFile.close();
} catch (IOException e) {
JOptionPane.showMessageDialog(null, "File does not exist", "Note", JOptionPane.INFORMATION_MESSAGE);
}
}

public SongDatabase() {
songList = new ArrayList<Song>();

readFile();
arrangePosition();
Container con = this.getContentPane();
con.setLayout(null);

lbSelectSong = new JLabel("Select Song");
lbSelectSong.setBounds(100, 30, 120, 25);
con.add(lbSelectSong);

cbSelectSong = new JComboBox();

for (int i = 0; i < songList.size(); i++) {
Song song = songList.get(i);
//Due to duplicate values in combo Box, Their was problem displaying values, adding a unique value to the name resolves the issue
cbSelectSong.addItem(i + 1 + ". " + song.getName());
}

//*******add Select Song drop down Label and Field ***//
cbSelectSong.setBounds(200, 30, 200, 25);
cbSelectSong.addItemListener(this);
add(cbSelectSong);

//*******add Item Code Label and Field ***********//
lbSongCode = new JLabel("Item Code");
lbSongCode.setBounds(100, 70, 120, 25);
con.add(lbSongCode);

tfSongCode = new JTextField(20);
tfSongCode.setBounds(200, 70, 200, 25);
con.add(tfSongCode);

//*******add Description Label and Field ***********//
lbSongDescription = new JLabel("Description");
lbSongDescription.setBounds(100, 110, 120, 25);
con.add(lbSongDescription);

tfSongDescription = new JTextField(20);
tfSongDescription.setBounds(200, 110, 200, 25);
con.add(tfSongDescription);

//*******add Artist Label and Field ***********//
lbSongArtist = new JLabel("Artist");
lbSongArtist.setBounds(100, 150, 120, 25);
con.add(lbSongArtist);

tfSongArtist = new JTextField(20);
tfSongArtist.setBounds(200, 150, 200, 25);
con.add(tfSongArtist);
//*******add Album Label and Field ***********//
lbSongAlbum = new JLabel("Album");
lbSongAlbum.setBounds(100, 190, 120, 25);
con.add(lbSongAlbum);

tfSongAlbum = new JTextField(20);
tfSongAlbum.setBounds(200, 190, 200, 25);
con.add(tfSongAlbum);
//*******add Price Label and Field ***********//
lbSongPrice = new JLabel("Price");
lbSongPrice.setBounds(100, 230, 120, 25);
con.add(lbSongPrice);

tfSongPrice = new JTextField(20);
tfSongPrice.setBounds(200, 230, 200, 25);
con.add(tfSongPrice);
//**********************************************//
//*******add "ADD" Button ***********//
addButton = new JButton("Add");
addButton.setBounds(10, 310, 90, 30);
addButton.addActionListener(this);
con.add(addButton);

//*******add "EDIT" Button ***********//
editButton = new JButton("Edit");
editButton.setBounds(110, 310, 80, 30);
editButton.addActionListener(this);
con.add(editButton);

//*******add "DELETE" Button ***********//
deleteButton = new JButton("Delete");
deleteButton.setBounds(210, 310, 80, 30);
deleteButton.addActionListener(this);
con.add(deleteButton);

//*******add "ACCEPT" Button ***********//
acceptButton = new JButton("Accept");
acceptButton.setBounds(310, 310, 80, 30);
acceptButton.addActionListener(this);
con.add(acceptButton);
//*******add "CANCEL" Button ***********//
cancelButton = new JButton("Cancel");
cancelButton.setBounds(410, 310, 80, 30);
cancelButton.addActionListener(this);
con.add(cancelButton);

//*******add " " Button ***********//
exitButton = new JButton("Exit");
exitButton.setBounds(170, 370, 80, 30);
exitButton.addActionListener(this);
con.add(exitButton);

//*******add "SAVE" Button ***********//
// saveButton=new JButton("SAVE");
// saveButton.setBounds(270,370,80,30);
// saveButton.addActionListener(this);
// con.add(saveButton);

//********************************************
if (songList.size() > 0) {
Song song = songList.get(0);
tfSongCode.setText(song.getItemCode());
tfSongDescription.setText(song.getDescription());
tfSongArtist.setText(song.getArtist());
tfSongAlbum.setText(song.getAlbum());
tfSongPrice.setText(song.getPrice());
}

tfSongCode.setEnabled(false); //the item Code field is disabled
tfSongDescription.setEnabled(false); //the Description field is disabled
tfSongArtist.setEnabled(false); //the Artist field is disabled
tfSongAlbum.setEnabled(false); //the Album field is disabled
tfSongPrice.setEnabled(false); //the Price field is disabled

addButton.setEnabled(true); // set the ADD button to be enabled
editButton.setEnabled(true); // set the EDIT button to be enabled
deleteButton.setEnabled(true); // set the DELETE button to be enabled
acceptButton.setEnabled(false); //the ACCEPT & CANCEL BUTTONS ARE DISABLED
cancelButton.setEnabled(false); //the ACCEPT & CANCEL BUTTONS ARE DISABLED
exitButton.setEnabled(true); // set the EXIT button to be enabled
// saveButton.setEnabled(true); // set the SAVE button to be enabled

setTitle("Song Database");
setSize(500, 500);
setVisible(true);
setResizable(false);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}

public void arrangePosition() {
Toolkit tookit = Toolkit.getDefaultToolkit();

Dimension scDimentions = tookit.getScreenSize();

int scHeight = (int) scDimentions.getHeight();

int scWidth = (int) scDimentions.getWidth();

int x = (scWidth - 500) / 2;

int y = (scHeight - 600) / 2;

setLocation(x, y);
}

@Override
public void actionPerformed(ActionEvent e) {

if (e.getSource() == addButton) {
Toolkit.getDefaultToolkit().beep();
flag = false;
editButton.setEnabled(false); // set the EDIT button to be disabled
deleteButton.setEnabled(false); // set the DELETE button to disabled
acceptButton.setEnabled(true); // set the ACCEPT button to be enabled
cancelButton.setEnabled(true); // set the CANCEL button to be enabled

tfSongCode.setText("");
tfSongDescription.setText("");
tfSongArtist.setText("");
tfSongAlbum.setText("");
tfSongPrice.setText("");

tfSongCode.setEnabled(true); //the item CODE field is enabled
tfSongDescription.setEnabled(true); //the item DESCRIPTION field is enabled
tfSongArtist.setEnabled(true); //the item ARTIST field is enabled
tfSongAlbum.setEnabled(true); //the item ALBUM field is enabled
tfSongPrice.setEnabled(true); //the item PRICE field is enabled

}
if (e.getSource() == editButton) {
Toolkit.getDefaultToolkit().beep();
flag = true;
tfSongCode.setEnabled(false); //the item CODE field is disabled
tfSongDescription.setEnabled(true); //the item DESCRIPTION field is enabled
tfSongArtist.setEnabled(true); //the item ARTIST field is enabled
tfSongAlbum.setEnabled(false); //the item ALBUM field is disabled
tfSongPrice.setEnabled(true); //the item PRICE field is enabled

addButton.setEnabled(false); // set the ADD button to be disabled
editButton.setEnabled(false); // set the EDIT button to be disabled
deleteButton.setEnabled(false); // set the DELETE button to disabled
acceptButton.setEnabled(true); // set the ACCEPT button to be enabled
cancelButton.setEnabled(true); // set the ACCEPT button to be enabled
exitButton.setEnabled(true); // set the CANCEL button to be enabled
// saveButton.setEnabled(true); // set the SAVE button to be enabled

tfSongDescription.setText("");
tfSongArtist.setText("");
tfSongPrice.setText("");

if (tfSongDescription.getText().length() == 0) {
JOptionPane.showMessageDialog(null, "Enter song description", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}
if (tfSongArtist.getText().length() == 0) {
JOptionPane.showMessageDialog(null, "Enter song artist", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}
if (tfSongPrice.getText().length() == 0) {
JOptionPane.showMessageDialog(null, "Enter song price", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}
}

if (e.getSource() == deleteButton) {

}
if (e.getSource() == acceptButton) {

if (tfSongCode.getText().length() == 0) {
JOptionPane.showMessageDialog(null, "Enter song code", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}

if (tfSongDescription.getText().length() == 0) {
JOptionPane.showMessageDialog(null, "Enter song description", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}

if (tfSongArtist.getText().length() == 0) {
JOptionPane.showMessageDialog(null, "Enter song artist", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}

if (tfSongAlbum.getText().length() == 0) {
JOptionPane.showMessageDialog(null, "Enter song album", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}

if (tfSongPrice.getText().length() == 0) {
JOptionPane.showMessageDialog(null, "Enter song price", "Note", JOptionPane.INFORMATION_MESSAGE);
return;
}

String name = tfSongDescription.getText();
String itemCode = tfSongCode.getText();
String description = tfSongDescription.getText();
String artist = tfSongArtist.getText();
String album = tfSongAlbum.getText();
String price = tfSongPrice.getText();

if (!flag) {
Song song = new Song(name, itemCode, description, artist, album, price);

songList.add(song);

cbSelectSong.addItem(song.getName());

JOptionPane.showMessageDialog(null, "New song added into list", "Note", JOptionPane.INFORMATION_MESSAGE);
} else {
Song song = new Song(name, itemCode, description, artist, album, price);

int index = cbSelectSong.getSelectedIndex();

songList.set(index, song);

cbSelectSong.remove(index);

cbSelectSong.addItem(name);

JOptionPane.showMessageDialog(null, "new song updated successfully", "Note", JOptionPane.INFORMATION_MESSAGE);
}
}
if (e.getSource() == cancelButton) {

if (songList.size() > 0) {
cbSelectSong.setSelectedIndex(0);

Song song = songList.get(0);

tfSongCode.setText(song.getItemCode());
tfSongDescription.setText(song.getDescription());
tfSongArtist.setText(song.getArtist());
tfSongAlbum.setText(song.getAlbum());
tfSongPrice.setText(song.getPrice());
}

tfSongCode.setEnabled(false); //the item CODE field is disabled
tfSongDescription.setEnabled(false); //the item DESCRIPTION field is disabled
tfSongArtist.setEnabled(false); //the item ARTIST field is disabled
tfSongAlbum.setEnabled(false); //the item ALBUM field is disabled
tfSongPrice.setEnabled(false); //the item PRICE field is disabled

addButton.setEnabled(true); // set the ADD button to be enabled
editButton.setEnabled(true); // set the EDIT button to be enabled
deleteButton.setEnabled(true); // set the DELETE button to be enabled
acceptButton.setEnabled(false); // set the ACCEPT button to be disabled
cancelButton.setEnabled(false); // set the CANCEL button to be disabled
exitButton.setEnabled(true); // set the EXIT button to be enabled
// saveButton.setEnabled(true); // set the SAVE button to be enabled

}

if (e.getSource() == exitButton) {
Toolkit.getDefaultToolkit().beep();

System.exit(0);
}

}

@Override
public void itemStateChanged(ItemEvent ie) {

int index = cbSelectSong.getSelectedIndex();

Song song = songList.get(index);

tfSongCode.setText(song.getItemCode());
tfSongDescription.setText(song.getDescription());
tfSongArtist.setText(song.getArtist());
tfSongAlbum.setText(song.getAlbum());
tfSongPrice.setText(song.getPrice());

tfSongCode.setEnabled(false); //the item CODE field is disabled
tfSongDescription.setEnabled(false); //the item DESCRIPTION field is disabled
tfSongArtist.setEnabled(false); //the item ARTIST field is disabled
tfSongAlbum.setEnabled(false); //the item ALBUM field is disabled
tfSongPrice.setEnabled(false); //the item PRICE field is disabled
}
}

============= Edit ===========

In my system the program is running fine, I have uploaded the screenshots. What problem do you have?

1. Code is not executing.

2. You can't see song names in dropdown(JComboBox)

For 1st problem, I would recommend you to update java(version 8 update 162), then copy-paste my code and run.

Song Database XSong Database Select Song 1. Yellow Submarine Select Song 6. Blue 1 Item Code BT012 Item Code BTO19 Description ellow Submarine Description Yellow Submarine Artist Ringo Stam Artist The Beaties Album The Beatles Album Beatles1 Price 12.99 Price 1.99 Add Edit Delete Accept Cancel Add Edit Delete Cancel Exit Exit