Java Swing类无法转换为DefaultListModel

Question

I'm working on a project with Swing and I have the following event handler:

private void txtInputKeyPressed(java.awt.event.KeyEvent evt) {                                    

    if (evt.getKeyCode() == ENTER) {
        DefaultListModel listModel = (DefaultListModel) lFrequencyTable.getModel();

        listModel.removeAllElements();

        ArrayList<FrequencyChar> table = 
                engine.computeFrequencyTable(txtInput.getText());

        for (FrequencyChar f: table) {
            listModel.addElement(f.character);
        }
    }
} 

A lot of the code is auto generated from Netbeans which is why I haven't posted all the UI code. I'm getting an exception when I try to initialize listModel: Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: brutus.BrutusUI$2 cannot be cast to javax.swing.DefaultListModel . BrutusUI is the swing UI class generated by NetBeans (it's just the main entry point of the app with all the components). However, NetBeans is showing me that the return value of lFrequencyTable.getModel(); is a ListModel so why would it be trying to cast the UI class as the DefaultListModel?

Answer 1

它不是试图将BrutusUI转换为DefaultListModel ，而是brutus.BrutusUI$2 ，其中$2表示在类BrutusUI声明的匿名类（实现ListModel ）。