Accessing a Panel being used in a ScrollPane

Question

Hey all. I'm having trouble accessing a Panel that I am placing inside a ScrollPane. I am getting a ClassCastException, trying to cast a JTextArea to an extension of JFrame.
I make the content of the ScrollPane using this code:
switch(jComboBox2.getSelectedIndex())
        case 0:
            jScrollPane2.setViewportView(null);
            break;
        case 1:
            jScrollPane2.getViewport().setView(new SemesterPanel());
            break;
        case 2:
            jScrollPane2.getViewport().setView(new TrimesterPanel());
            break;
        case 3:
            jScrollPane2.getViewport().setView(new QuarterPanel());
            break;
        case 4:
            jScrollPane2.getViewport().setView(new UnitPanel());
            break;
    }And then I later try to access the Panels using this:
if(jComboBox2.getSelectedIndex() == 1)
        SemesterPanel p = (SemesterPanel)jScrollPane1.getViewport().getView(); //<----- THIS IS THE PROBLEM
        s = p.getData();
        data1 = s[0];
        data2 = s[1];
    }I've marked the problematic line w/ a comment. I'm not sure if that's how I am supposed to access the JPanel extension using that method. If not, how should I do it? Why am I getting a JTextArea (the SemesterPanel object contains a JTextArea but it has a JLabel before that, so I'm not sure why...)
Thanks,
Tyler

Answer 1

SemesterPanel p = (SemesterPanel)jScrollPane1.getViewport().getView(); Well break you code up into multiple statements so you can see whats going on.
JViewport viewport = scrollPane.getViewport();
Component component = viewport.getView();
System.out.println(component.getClass());If the component isn't what you expect it to be then you built the scrollpane incorrectly and we can't tell what you did based on the code you provided.
If you need further help then you need to create a [Short, Self Contained, Compilable and Executable, Example Program (SSCCE)|http://homepage1.nifty.com/algafield/sscce.html], that demonstrates the incorrect behaviour.