Update JList problem

[ostkanten]

This code:

private JList konton;
List<Account> accounts = new ArrayList();
....
public void updateAccountList(JList konton, List accounts){
	    DefaultListModel listModel = (DefaultListModel)konton.getModel(); // line 711
	    for(int i=0; i<accounts.size(); i++){
	        listModel.addElement((String)accounts.get(i));
	    }
	    revalidate(); 	
}

gives error:

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: javax.swing.JList$4 cannot be cast to javax.swing.DefaultListModel
at GUI.updateAccountList(GUI.java:711)
at GUI$UpdateAccountListener.actionPerformed(GUI.java :259)

I have read a lot at Internet about this problem but I still don´t know how to solve it? Any suggestions?

[Tolls]

Clearly the ListModel is not a DefaultListModel but something internal to JList (that's what the $4 means, a class defined inside JList).
Why not just use ListModel?

[eRaaaa]

Your JList konton does not use a DefaultListModel as its model so you can`t cast it to a DefaultListModel :)!
-> System.out.println(konton.getModel().getClass()); //prints javax.swing.JList$4 instead of DefaultListModel ?

You have to create a DefaultListModel and set it as the model of your jlist.
How do you create the jlist?

[ostkanten]

I did forget that. JList is created like

konton=new JList(new DefaultListModel());

Can I exclude Default and use ListModel to get it work?

[DarrylBurke]

To get better help sooner, post a SSCCE (Short, Self Contained, Correct (Compilable), Example) that demonstrates the problem. Not all your code, just a GUI with a JList constructed the way you are doing it, and the method that throws the Exception with maybe a JButton to invoke that method.

Unrelated, but any class that has more than 711 lines probably could benefit from refactoring.

Are you sure you didn't initialize the JList with an array?

db

[DarrylBurke]

Why not just use ListModel?

addElement(...) is defined in DefaultListModel.

db