add KeyListener to JLabel

I want to make a class extend from JLabel and implement KeyListener, but KeyListener doesn't work. Now MouseListener works but KeyListner doesn't work, but why? Another problem is when setting the layout of JFrame to null, it doesn't show (images car or car object).

    public class car extends JLabel implements KeyListener,MouseListener{
        private ImageIcon imgico;//to set Image icon of car
        public car(int car_num,boolean line1,Dimension position){
            //car_num variable check which of Image of car load
            //if line1 is true .line 1 else car load in line 2
            super();
            this.imgico = this.car_load(car_num, line1);
            super.setIcon(this.imgico);
            super.setVisible(true);
            super.setSize(this.imgico.getIconWidth(),this.imgico.getIconHeight());
            super.setLocation(position.width, position.height);
            this.addKeyListener(this);
            this.addMouseListener(this);

        }
        private ImageIcon car_load(int car_num,boolean line1){
            //load image icon of car
            if (car_num == 1 && line1 == true)
                return (new ImageIcon("Images/cars/01a.PNG"));
            else if (car_num == 1 && line1 == false)
                return (new ImageIcon("Images/cars/01b.PNG"));
            else if (car_num == 2 && line1 == true)
                return (new ImageIcon("Images/cars/02a.PNG"));
            else if (car_num == 2 && line1 == false)
                return (new ImageIcon("Images/cars/02b.PNG"));
            else if (car_num == 3 && line1 == true)
                return (new ImageIcon("Images/cars/03a.PNG"));
            else if (car_num == 3 && line1 == false)
                return (new ImageIcon("Images/cars/03b.PNG"));
            else if (car_num == 4 && line1 == true)
                return (new ImageIcon("Images/cars/04a.PNG"));
            else if (ca开发者_JAVA百科r_num == 4 && line1 == false)
                return (new ImageIcon("Images/cars/04b.PNG"));
            else if (car_num == 5 && line1 == true)
                return (new ImageIcon("Images/cars/05a.PNG"));
            else if (car_num == 5 && line1 == false)
                return (new ImageIcon("Images/cars/05b.PNG"));
            else if (car_num == 6 && line1 == true)
                return (new ImageIcon("Images/cars/06a.PNG"));
            else
                return (new ImageIcon("Images/cars/06b.PNG"));
            // by deafult its 06b 
        }
        @Override
        public void keyPressed(KeyEvent arg0) {
            // TODO Auto-generated method stub
            System.out.println(arg0.getKeyCode());
        }
        @Override
        public void keyReleased(KeyEvent arg0) {
            // TODO Auto-generated method stub

        }
        @Override
        public void keyTyped(KeyEvent arg0) {
            // TODO Auto-generated method stub
            System.out.println(arg0.getKeyCode());

        }
        @Override
        public void mouseClicked(MouseEvent arg0) {
            if (arg0.getSource() == this)
                System.out.println("Hi");
        }
        @Override
        public void mouseEntered(MouseEvent arg0) {
            // TODO Auto-generated method stub

        }
        @Override
        public void mouseExited(MouseEvent arg0) {
            // TODO Auto-generated method stub

        }
        @Override
        public void mousePressed(MouseEvent arg0) {
            // TODO Auto-generated method stub

        }
        @Override
        public void mouseReleased(MouseEvent arg0) {
            // TODO Auto-generated method stub

        }
    }

In main:

    JFrame x = new JFrame();
    x.setSize(500,500);
    x.setVisible(true);
    Dimension v = new Dimension(5,5);
    car t =new car(1,true,v);
    x.setLayout(null);
    x.add(t);

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I don't think JLabel can gain focus, thus a KeyEvent would never be fired. See this documentation for further details.

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try this

Jlabel.addMouseListener(new MouseAdapter()  
{  
  public void mouseClicked(MouseEvent e)  
  {  
    //Do whatever You want
  }  
});