Populating JTable with Vector?

Question

I am getting the following error when I try to populate a JTable using vectors.

Error:

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.String cannot be cast to java.util.Vector
    at javax.swing.table.DefaultTableModel.justifyRows(DefaultTableModel.java:268)
    at javax.swing.table.DefaultTableModel.setDataVector(DefaultTableModel.java:224)
    at javax.swing.table.DefaultTableModel.<init>(DefaultTableModel.java:159)
    at Package_Sync.Package_sync$Model.<init>(Package_sync.java:50)
    at Package_Sync.Package_sync.packageTable(Package_sync.java:43)
    at Package_Sync.Package_sync.<init>(Package_sync.java:16)
    at Package_Sync.Package_sync$2.run(Package_sync.java:116)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

Here is my code:

private void packageTable() {
    Vector tableHeadings = new Vector();
    tableHeadings.add("PACKAGE NAMES");
    tableHeadings.add("SHOW");
    Table1.setModel(new Model(fileVector, tableHeadings));
}

class Model extends DefaultTableModel {
    Vector heading = null;
    Model(Vector data, Vector heading) {
        super(data, heading);
        this.heading = heading;
    }

    public Class getColumnClass(int cols) {
        if (getValueAt(0, cols) != null && cols > 0) {
            return getValueAt(0, cols).getClass();
        } else {
            return String.class;
        }
    }
}

What is the problem with my code?

Answer 1

From the exception, you must added String object to fileVector, like this:

Vector fileVector = new Vector();
fileVector.add("a string object");

This is against the implementation of DefaultTableModel, to use it you need to add Vector object into fileVector, like this:

Vector fileVector = new Vector();
fileVector.add(new Vector(Arrays.asList(new String[]{"row1 col1", "row1 col2"})));
fileVector.add(new Vector(Arrays.asList(new String[]{"row2 col1", "row2 col2"})));

Cheers