Error on Vector in Java

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Error on Vector in Java

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#1 by (2 votes)

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I would appreciate if someone can help me with the following error:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at folder.ConfigTeclado.guardaConfig (ConfigTeclado.java:91)

The code (only the parts where I use it) is as follows:

public class ConfigTeclado extends JPanel implements ActionListener,KeyListener{
    private Vector teclas = new Vector();
    public void keyPressed(KeyEvent e){ }

    public void keyReleased(KeyEvent e){
        Boolean ver=true;
        if(!ban){
            for(int i=0;i<b.length && ver;i++){ 
                 if(b[i].getLabel().equals(e.getKeyText(e.getExtendedKeyCode())))
                ver=false;  
            }
            teclas.add(e.getKeyCode());        
            if(ver){
                a.setLabel(e.getKeyText(e.getExtendedKeyCode()));             
                ban=true;              
            }        
        }
    }

    public void guardaConfig(){ 
        bd.inicializar();             
        bd.actualizarConfiguracion("UP", (int)teclas.elementAt(0));
        bd.actualizarConfiguracion("DOWN", (int)teclas.elementAt(1));
        bd.actualizarConfiguracion("LEFT", (int)teclas.elementAt(2));
        bd.actualizarConfiguracion("RIGHT", (int)teclas.elementAt(3));
        bd.cerrar();
    }
}

Thank you very much!

java array nullpointerexception error404

asked by Valentina 01.08.2018 в 20:26

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1 answer

How to add text to a text area Problems with transform and z-index CSS

score 2 · Answer 1

It is possible that bd (in saveConfig ()) has null value or does not exist, generally a nullPointerException is given when you try to change a value or use a method of something that is not really initialized or has not been assigned a value to despite having been referenced to some type of data or object.

Even if it's incoherent because you're just trying to do that here:

bd.inicializar();

The issue is if bd, at that time, was the object that it required to be able to call the initialize method or not.