I'm trying to create a Java application that receives a song through JFileChooser and adds that song to a list ( ArrayList<File> ).
But when you access the array.getindex(0).getPath() file, the system drops NullPointerException .
Here is the code:
package br.lp2.view;
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.nio.file.Path;
import java.util.ArrayList;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.*;
import br.lp2.player.*;
import javazoom.jl.decoder.JavaLayerException;
import javazoom.jl.player.Player;
import javazoom.jl.player.advanced.AdvancedPlayer;
import br.lp2.main.*;
@SuppressWarnings({ "serial", "unused" })
public class GUI extends JFrame {
JFileChooser jfile;
Component parent = null;
//private Player ply;
// Dimensoes da tela principal
private int ALTURA = 300;
private int LARGURA = 500;
//Player
File p1Player;
ArrayList<File> arrayMusic = new ArrayList<File>();
private Player pl = null;
// Janela de cadastro de usuario
private CadastroUsuario cadastroUsuario = new CadastroUsuario();
// Menu bar
private JMenuBar menuBar = new JMenuBar();
// Menus
private JMenu menuMusicas = new JMenu("Musicas");
private JMenu menuPlaylists = new JMenu("Playlists");
private JMenu menuUsuarios = new JMenu("Usuarios");
// Menu items
private JMenuItem adicionarMusica = new JMenuItem("Adicionar musica");
private JMenuItem removerMusica = new JMenuItem("Remover musica");
private JMenuItem verMusicas = new JMenuItem("Ver lista de musicas");
private JMenuItem verPlaylists = new JMenuItem("Ver playlists");
private JMenuItem criarPlaylist = new JMenuItem("Criar playlist");
private JMenuItem removerPlaylist = new JMenuItem("Remover playlist");
private JMenuItem verUsuarios = new JMenuItem("Ver lista de usuarios");
private JMenuItem adicionarUsuario = new JMenuItem("Cadastrar usuarios");
private JMenuItem removerUsuario = new JMenuItem("Remover usuario");
// Botoes
private JButton play = new JButton("Play");
private JButton pause = new JButton("Pause");
private JButton proximaMusica = new JButton(">>");
private JButton anteriorMusica = new JButton("<<");
public GUI() {
jfile = new JFileChooser();
// Configuracoes padrao
setTitle("Player de musica");
setSize(LARGURA, ALTURA);
setLayout(null);
setVisible(true);
setResizable(false);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
// Adicionando menu
menuBar.add(menuMusicas);
menuBar.add(menuPlaylists);
menuBar.add(menuUsuarios);
// Adicionando itens aos menus
menuMusicas.add(verMusicas);
menuMusicas.add(adicionarMusica);
menuMusicas.add(removerMusica);
menuPlaylists.add(verPlaylists);
menuPlaylists.add(criarPlaylist);
menuPlaylists.add(removerPlaylist);
menuUsuarios.add(verUsuarios);
menuUsuarios.add(adicionarUsuario);
menuUsuarios.add(removerUsuario);
// Setando menubar
setJMenuBar(menuBar);
// Adicionando botoes
add(play);
add(pause);
add(proximaMusica);
add(anteriorMusica);
// Setando posicao dos botoes
play.setBounds(70, ALTURA - 90, 100, 30);
pause.setBounds(180, ALTURA - 90, 100, 30);
proximaMusica.setBounds(290, ALTURA - 90, 50, 30);
anteriorMusica.setBounds(10, ALTURA - 90, 50, 30);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pause.setEnabled(false);
// Login inicial
// Login login = new Login();
// Eventos
adicionarMusica.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
jfile.showOpenDialog(parent);
p1Player = jfile.getSelectedFile();
try{
arrayMusic.add(p1Player);
}catch (NullPointerException ex){
System.out.println(ex.getMessage());
System.out.println(ex.getStackTrace());
}
}
});
play.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
pause.setEnabled(true);
play.setEnabled(false);
Music msc = new Music();
msc.start();
}
});
pause.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
play.setEnabled(true);
}
});
adicionarUsuario.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
cadastroUsuario.setVisible(true);
}
});
}
/*class Music extends Thread implements Runnable{
public void run(File file_t) throws FileNotFoundException{
System.out.println("chegou aqui");
FileInputStream input = new FileInputStream(file_t);
PlayerFile ply = new PlayerFile(file_t);
Thread playing = new Thread((Runnable) ply);
playing.run();
}
}*/
class Music extends Thread{
public void run(){
try {
System.out.println("chegou aqui222");
//System.out.println("CAMINHO " + arrayMusic.get(0).getPath());
InputStream teste = this.getClass().getResourceAsStream("C:/Users/pedrohbcavalcante/Downloads/ateste.mp3");
//System.out.println("GETPATH() " + file.getPath() + " GETABSOLUTPATH() "+ file.getAbsolutePath());
pl = new Player(teste);
pl.play();
} catch (JavaLayerException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
}
It resulted in the following stacktrace:
Exception in thread "Thread-3" java.lang.NullPointerException: in
at javazoom.jl.decoder.Bitstream.<init>(Unknown Source)
at javazoom.jl.player.Player.<init>(Unknown Source)
at javazoom.jl.player.Player.<init>(Unknown Source)
at br.lp2.view.GUI$Music.run(GUI.java:174)