regarding JTable data

[tadi raja]

I was created one JTable and i can add data to JTable as by extends the DefaultTableModel, if i pressed "clear" button the rows of DefaultTableModel can be cleared, and once again i add new data to JTable
Here is the implemented code of CustomTableModel that extends DefaultTableModel

 
 
import javax.swing.*;
import javax.swing.table.*;
import java.util.*;
 
public class CustomTableModel extends DefaultTableModel
{
    public Vector dataRows;
         
    public CustomTableModel()
     {
    setColumnIdentifiers(new String[] {"Study","Drug1","Diluent1","Drug2","Diluent2","Solution","Finding"});
    
    Vector dataVector = new Vector();
    
    dataVector = dataRows;
     }
 
    public int getColumnCount()
     {
        return 7;
     }
        
    public void addRowToTable(String a, String b, String c, String d, String e,String f, String g)
     {
        String[] rowData = new String[7];
                           
        rowData[0] = a;
        rowData[1] = b;
        rowData[2] = c;
        rowData[3] = d;
        rowData[4] = e;
        rowData[5] = f;
        rowData[6] = g;
        
        dataRows.addElement(rowData);          
        fireTableDataChanged();
     }
 
    public int getRowCount()
     {
        if(dataRows == null)
        {
        dataRows = new Vector();
        }
            return dataRows.size();
     }
   
   public Object getValueAt(int row, int column)
     {
     Object[] sr = (Object[])dataRows.elementAt(row);
         
     return sr[column];
     }
   
   public void clear()
   {
   dataRows.clear();
   }
 }
 

i got the exception like this:

Exception: java.lang.ArrayIndexOutOfBoundsException: -1
at java.util.Vector.elementAt(Vector.java:434)
at com.hdsc.plus.app.vista.app.ivcheck.CustomTableModel.getValueAt(CustomTableModel.java:52)
at javax.swing.JTable.getValueAt(JTable.java:1771)
at com.perse.swing.standard.StandardTableUI.paint(StandardTableUI.java:49)
at javax.swing.plaf.ComponentUI.update(ComponentUI.java:142)
at javax.swing.JComponent.paintComponent(JComponent.java:541)
at javax.swing.JComponent.paint(JComponent.java:808)
at javax.swing.JComponent.paintChildren(JComponent.java:647)
at javax.swing.JComponent.paint(JComponent.java:817)
at javax.swing.JViewport.paint(JViewport.java:722)
at com.perse.swing.standard.StandardScrollPane$MessageViewport.paint(StandardScrollPane.java:100)
at javax.swing.JComponent.paintChildren(JComponent.java:647)
at javax.swing.JComponent.paint(JComponent.java:817)
at javax.swing.JComponent.paintChildren(JComponent.java:647)
at javax.swing.JComponent.paint(JComponent.java:817)
at javax.swing.JComponent.paintChildren(JComponent.java:647)
at javax.swing.JComponent.paint(JComponent.java:817)
at javax.swing.JComponent.paintChildren(JComponent.java:647)
at javax.swing.JComponent.paint(JComponent.java:817)
at javax.swing.JComponent.paintChildren(JComponent.java:647)
at javax.swing.JComponent.paint(JComponent.java:817)
at javax.swing.JComponent.paintChildren(JComponent.java:647)
at javax.swing.JComponent.paint(JComponent.java:817)
at javax.swing.JComponent.paintWithOffscreenBuffer(JComponent.java:4795)
at javax.swing.JComponent.paintDoubleBuffered(JComponent.java:4758)
at javax.swing.JComponent._paintImmediately(JComponent.java:4692)
at javax.swing.JComponent.paintImmediately(JComponent.java:4495)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:410)
at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueUtilities.java:117)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:454)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)

how to resolve this problem?

Thanks you in advance

[Rob Spoor]

I don't know why this error occurs, but I have one major doubt about your code. If you are extending DefaultTableModel, then why are you recreating part of that functionality?

I'd use DefaultTableModels behaviour, and use it instead:

public class CustomTableModel extends DefaultTableModel
{
    // DefaultTableModel has its own internal storage; use that
         
    public CustomTableModel()
    {
        super(new String[] {"Study","Drug1","Diluent1","Drug2","Diluent2","Solution","Finding"}, 0);
    }
 
    // let's use DefaultTableModel's own getColumnCount implementation 
 
    public void addRowToTable(String a, String b, String c, String d, String e,String f, String g)
    {
        String[] rowData = new String[7];
                           
        rowData[0] = a;
        rowData[1] = b;
        rowData[2] = c;
        rowData[3] = d;
        rowData[4] = e;
        rowData[5] = f;
        rowData[6] = g;
 
        // use DefaultTableModel's add method; it will trigger the change as well
        super.addRow(rowData);
    }
 
    // let's use DefaultTableModel's own getRowCount implementation 
 
    // and getValueAt
 
    // there is no clear method, so let's add this one   
    public void clear()
    {
        // setting the number of rows to 0 also clears the model
        setRowCount(0);
    }
}

[ September 13, 2008: Message edited by: Rob Prime ]

[tadi raja]

Hi Rob Prime

I found the solution, your code worked perfectly without any exception.

Thanks alot