Ho un problema con i listener dei Jslider. Ecco il codice:

class jslider extends ChangeListener{
public void stateChanged(ChangeEvent evt){
JSlider source = (JSlider)evt.getSource();
if(!source.getValueIsAdjusting()){
secondi = (int)source.getValue();
}
}
}
richiamo sul mio slider: anima.addChangeListener(new jslider())

Compilando escono i seguenti errori:

menu_p.java:1502: cannot resolve symbol
symbol : class ChangeListener
location: class menu_p.jslider
class jslider extends ChangeListener{
^
menu_p.java:1503: cannot resolve symbol
symbol : class ChangeEvent
location: class menu_p.jslider
public void stateChanged(ChangeEvent evt){
^
2 errors

Sapete il motivo