Java/Netbeans: JList.getModel() returns a ListModel instead of a DefaultListModel

Question

I am creating a java application using NetBeans 7.3.
I have a "Create New Foo" wizard that shares a JPanel across multiple frames.
The JPanel object implements a JList that I have setup as shown here:

http://img811.imageshack.us/img811/5717/customcodepvmarketlist.jpg

Using another function, I want to be able to test the contents of the JList, like so:

//Adds a market to the list, if it doesn't exist.
//Removes a market from the list, if it does exist.
//If removing a market causes the list to become empty,
//insert 'None'

public String modifyMarket(String market) {
    if(pvMarketList.getModel().contains(market)) {
        //More Code   
    }         
}

I can't do the above test on '.contains(market)' because .getModel() is returning a ListModel instead of a DefaultListModel.

What is the problem? How can I fix this?

UPDATE
I might be able to work around the issue by casting the ListModel as a DefaultListModel, but I remain confused as to why ListModel is what is being returned.

Answer 1

A JList needs an instance of ListModel to work. This instance could be an instance of DefaultListModel, but you could create your own ListModel implementation and use it instead of DefaultListModel.

BTW, note by the constructors of JList construct a JList with a ListModel that is not an instance of DefaultListModel.

If you know that it is a DefaultListModel, because that's what you passed when constructing the list, then you can safely cast the returned ListModel to DefaultListModel.