For this you should use the actionCommand:
//after object creation:
upperCombo.setActionCommand("upper");
lowerCombo.setActionCommand("lower");
And then in your actionPerformed():
String command = event.getActionCommand();
if("upper".equals(command)){
//Do something
} else if("lower".equals(command)){
//Do something
}
Does this solve your problem, or did I misunderstood you?
EDIT:
What about somthing like this:
String command = event.getActionCommand();
if("upper".equals(command)){
lowerCombo.removeActionListener(this);
//Do your changes
lowerCombo.addActionListener(this);
} else if("lower".equals(command)){
//Do something
}
EDIT (again ;)):
class YourClass{
private ActionListener lowerActionListener = new java.awt.event.ActionListener() {
void actionPerformed(java.awt.event.ActionEvent evt) {
//doSomething
}
};
//...
// maybe in the constructor, after object-creation
lowerCB.addActionListener(lowerActionListener);
//...
// in th actionPerfomed() method
lowerCB.removeActionListener(lowerActionListener);
}