JTable moving items strangeness (desperate now)...

Question

Hi there,
I've got a major problem that I just can't figure out. I've got two JTables, each with an instance of the
below datamodel. I've got two buttons. I want to highlight certain rows on the left JTable and use one of
the buttons to move across the selected items to the JTable on the right.
Two problems - the first is that the selected items are copied across fine, but instead of removing the
selected rows from the left JTable after copying to the right JTable, it leaves a random one. The other
problem is that if I highlight rows from near the bottom of the lefthand JTable, I get an
ArrayIndexOutOfBoundsException.
What the hell is going wrong here? I'm at a total loss.
This is my datamodel for both JTables...
import javax.swing.table.AbstractTableModel;
import java.util.Collection;
import java.util.ArrayList;
import java.util.Vector;
import java.util.Map;
import java.util.List;
import java.util.Iterator;
import java.util.Set;
import commonfiles.Utility;
public class ListDataModel extends AbstractTableModel implements Cloneable {
    private final int NUM_COLUMNS = 3;
    private Vector theRowData;
    private String[] columnNames = {"USERS_REFNO", "CODE", "USER_NAME"};
    // Constructor : Create empty data model.
    public ListDataModel() {
        theRowData = new Vector();
    // Constructor : Create data model from another collection.
    public ListDataModel(Collection someCollection) {
        theRowData = new Vector();
        theRowData.addAll(someCollection);
    public ListDataModel(List arrayCollection) {
        ArrayList theColumnArray;
        Map rowMap;
        theRowData = new Vector();
        for (int i = 0; i < arrayCollection.size(); i++) {
            rowMap = (Map)arrayCollection.get(i);
            theColumnArray = new ArrayList();
            theColumnArray.add((Object)rowMap.get(columnNames[0]));
            theColumnArray.add((Object)rowMap.get(columnNames[1]));
            theColumnArray.add((Object)rowMap.get(columnNames[2]));
            theRowData.add(theColumnArray);
    public Object clone() {
        try {
            return super.clone();
        } catch (CloneNotSupportedException cnse) {
            throw new RuntimeException(cnse.toString());
    public Object getValueAt(int rowIndex, int columnIndex) {
        ArrayList theColumnArray;
        theColumnArray = (ArrayList)theRowData.get(rowIndex);
        return(Object)theColumnArray.get(columnIndex);
    public List getRowAt(int rowIndex) {
        return (ArrayList)theRowData.get(rowIndex);
    public void removeRowAt(int rowIndex) {                       // <- Exception thrown here.
        theRowData.removeElementAt(rowIndex);
    public void addRow(List rowObject) {
        theRowData.addElement(rowObject);
    // Check to see if a particular Table cell is editable.
    // In this model, none of the cells are directly editable.
    public boolean isCellEditable(int rowIndex, int columnIndex) {
        return false;
    public int getColumnCount() {
        return columnNames.length;
    // Return the column headers.
    public String[] returnColumnNames() {
        return columnNames;
    // Return the name of a specific column.
    public String getColumnName(int col) {
        return columnNames[col].toString();
    public int getRowCount() {
        return theRowData.size();
    public Vector returnAllData() {
        return theRowData;
}...and this is the code I'm using when I press the button to move the selected rows from the left JTable to
the right JTable.
public void actionPerformed(ActionEvent e) {
        int[] selectedRows;
        List listItem;
        // Event that happens when the List Add (>>) button is pressed.
        if (e.getSource() == btnListAdd) {
            // Get the number of selected (hightlighted) rows.
            selectedRows = this.tableUserList.getSelectedRows();
            if (selectedRows.length > 0) {
                for (int row = 0; row < selectedRows.length; row++) {
                    listItem = ((ListDataModel)tableUserList.getModel()).getRowAt(selectedRows[row]);
                    ((ListDataModel)tableExcludeList.getModel()).addRow(listItem);
                for (int row = 0; row < selectedRows.length; row++) {
                    ((ListDataModel)tableUserList.getModel()).removeRowAt(selectedRows[row]);
                tableUserList.clearSelection();
                tableUserList.revalidate();
                tableUserList.repaint();
                tableExcludeList.revalidate();
                tableExcludeList.repaint();
    }Here is the stacktrace for the IndexArrayOutOfBoundsException...
Exception occurred during event dispatching:
java.lang.ArrayIndexOutOfBoundsException: 22 >= 22
at java.util.Vector.removeElementAt(Vector.java:517)
at ListDataModel.removeRowAt(ListDataModel.java:66)
at ExcludeListFrame.actionPerformed(ExcludeListFrame.java:177)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:17
86)
I'm in desperate need of help with this. The errors just don't make logical sense to me. Little help folks?
Thanks.

Answer 1

Here's your problem :
When you remove an element from your Vector, its size decreses.
Let's say you have 10 objects in your Vector :
the first time you remove an element, its size will become 9 (from 0 to 8)... and imagine that the second index of your int array is 9 !! you are out of bounds!!
what you should do is pass the entire indexes array to your data model, then create a new Vector (let's call it vect2) that you will feed with the objects pointed by your indexes.
then you remove the whole vector :
myData.removeAll(vect2);