Fórum Trocar a imagem quando clicar no botão #568974

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
	at javax.swing.ImageIcon.<init>(Unknown Source)
	at BotaoComando.actionPerformed(BotaoComando.java:66)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;

import javax.swing.ImageIcon;  
import javax.swing.JFrame;  
import javax.swing.JLabel;  

//criar um novo metodo, usando ImageButton;

public class BotaoComando extends JFrame implements ActionListener {
	JButton botaoComando;
	String pedindoComando = "@@@,a?,&";
	char[] comandoChar = pedindoComando.toCharArray();  
	int[] comandoInteiro = new int[comandoChar.length];
	JLabel label;  
	
	DriverSerial driver;// = new DriverSerial ("comandoInteiro");   
	
    public BotaoComando()
 
    {
        super(" Controle ");
 
        Container tela = getContentPane();
        tela.setLayout(null);
        
        botaoComando = new JButton ("Controle TV");
        botaoComando.setBounds(180, 30, 100, 40);
        ImageIcon img = (new ImageIcon("C:/Katarina/Controle/controle.jpg")); 
        
        if(img == null)
        {
        	System.out.println("erro");
        }              
                       
        label = new JLabel(img);
        label.setBounds(80,80,290,290);
                
        tela.add(botaoComando);
        tela.add(label);
        this.setSize(600,440); 
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.setVisible(true); 
       
        botaoComando.addActionListener((ActionListener) this);
                       
        botaoComando.setToolTipText("Clique neste botão "
				+ "para usar o controle.");
        
        driver = new DriverSerial("Controle TV"); 
        driver.open();
        
   }
    
    private boolean ImageIcon(String string) {
		// TODO Auto-generated method stub
		return false;
	}

    public void actionPerformed(ActionEvent e) 
    {	    
    	
    	JLabel Jlabel = null;
		Jlabel.setIcon(new javax.swing.ImageIcon(getClass().getResource("C:/Katarina/Controle/ctr.jpg")));
    	
    //	botaoComando.setActionCommand("C:/Katarina/Controle/ctr.jpg");
    	
      for (int cont = 0; cont >= comandoInteiro.length; cont++)
      {
    	  System.out.println (comandoInteiro[0]);
      }
     	//System.out.println("Testando código");
    	driver.sendBytes(comandoInteiro); 
       
     }
    public static void main(String args[]) 
    {
       	new BotaoComando();      	
    }


 }

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

//criar um novo metodo, usando ImageButton;

public class BotaoComando extends JFrame implements ActionListener {
	JButton botaoComando;
	String pedindoComando = "@@@,a?,&";
	char[] comandoChar = pedindoComando.toCharArray();
	int[] comandoInteiro = new int[comandoChar.length];
	JLabel label;
	String name = "C:/Katarina/Controle/ctr.jpg";
	ImageIcon img = new ImageIcon(getClass().getResource("C:/Katarina/Controle/controle.jpg")); 
	ImageIcon img2 = new ImageIcon(getClass().getResource("C:/Katarina/Controle/ctr.jpg")); 
	DriverSerial driver;// = new DriverSerial ("comandoInteiro");
	
	public BotaoComando() {

		super(" Controle ");

		Container tela = getContentPane();
		tela.setLayout(null);

		botaoComando = new JButton("Controle TV");
		botaoComando.setBounds(180, 30, 100, 40);
		//ImageIcon img = new ImageIcon("C:/Katarina/Controle/controle.jpg");
		//ImageIcon img2 = new ImageIcon(getClass().getResource("C:/Katarina/Controle/ctr.jpg")); 
		//ImageIcon img = new ImageIcon(getClass().getResource("C:/Katarina/Controle/ctr.jpg"));
		//ImageIcon img = new ImageIcon(Menu.class.getResource("C:/Katarina/Controle/ctr.jpg"));
		
		if (img == null) {
			System.out.println("erro");
		}

		label = new JLabel(img);
		label.setBounds(80, 80, 290, 290);

		tela.add(botaoComando);
		tela.add(label);
		this.setSize(600, 440);
		this.setDefaultCloseOperation(EXIT_ON_CLOSE);
		this.setVisible(true);

		botaoComando.addActionListener(this);
		
		botaoComando.setToolTipText("Clique neste botão "
				+ "para usar o controle.");

		driver = new DriverSerial("Controle TV");
		driver.open();
		
	}

	private boolean ImageIcon(String string) {
		// TODO Auto-generated method stub
		return false;
	}

	public void actionPerformed(ActionEvent e) {

		if (e.getSource() == this.botaoComando){
			System.out.println("Apertado");
			botaoComando.setActionCommand(name);
			botaoComando.setIcon(img2);
					
		
		}
		else
			System.out.println("Apertado2");
		
		
		// JLabel Jlabel = null;

		// Jlabel.setIcon(new javax.swing.ImageIcon(getClass().getResource(
		// "C:/Katarina/Controle/ctr.jpg")));

		for (int cont = 0; cont >= comandoInteiro.length; cont++)

			System.out.println(comandoInteiro[0]);

	}

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

}

Exception in thread "main" java.lang.NullPointerException
    at javax.swing.ImageIcon.<init>(Unknown Source)
    ...

...
ImageIcon img = new ImageIcon(getClass().getResource("controle.jpg"));
...