Adding Rows Dynamically using AbstractTableModel

Question

I would do anything for some help on this one. I have a JTable that has 5 rows within 1 column. After the user gets to the 5th row I want them another row to be added so that they could add informatoin in there. When I do this with the following code below nothing happens and my column count ends up being -1 right after I do this. If anyone could help it this would be a great help. The output in my console when I end up putting information into all the rows up to the 4th one is the following.
Vector size 0
column count1
column count1
row 0column 0
row 1column 0
row 2column 0
row 3column 0
row 4column 0
column count1
row 4column -1
/*********This is my AbstractTableModel Class *********/
package com.ibm.esup.agent.dataqmonitor;
* @author garbersb
* This class sets up the Table Model for the Message Input Queue.
import java.util.*;
import javax.swing.table.*;
import javax.swing.*;
public class QueueTableModel extends DefaultTableModel
     /** Vector where the message information will be kept. */
     Vector data = null;
     /** Number of columns within the input queue table. */
     protected static int NUM_COLUMNS = 1;
     /** Number of rows within the input queue table. */
     protected static int START_NUM_ROWS = 5;
     /** Next row that could be empty. */
     protected int nextEmptyRow = 0;
     /** Number of rows we are at. */
     protected int numRows = 0;
     * @see java.lang.Object#Object()
     * This will end up creating a Vector when this gets created.
     public QueueTableModel()
          data = new Vector();
          System.out.println("Vector size " + data.size());
     * @see javax.swing.table.TableModel#getColumnName(int)
     * This will allow us to get the Column Name.
     public String getColumnName(int column)
          switch (column)
          return "";
     * @see javax.swing.table.TableModel#getColumnCount()
     public synchronized int getColumnCount()
          System.out.println("column count" + NUM_COLUMNS);
          return NUM_COLUMNS;
     * @see javax.swing.table.TableModel#getRowCount()
     public synchronized int getRowCount()
          if (numRows < START_NUM_ROWS)
               return START_NUM_ROWS;
          else
               return numRows;
     * @see javax.swing.table.TableModel#getValueAt(int, int)
     public synchronized Object getValueAt(int row, int column)
          try
               String queue = (String) data.elementAt(row);
               switch (column)
                    case 0 :
                         return queue;
          catch (Exception e)
          return "";
     * Don't need to implement this method unless your table's
     * editable.
     public boolean isCellEditable(int row, int col)
          return true;
     * Don't need to implement this method unless your table's
     * data can change.
     public void setValueAt(Object value, int row, int col)
          String queueValue = (String) value;
          data.addElement(queueValue);
          fireTableCellUpdated(row, col);
     * * inserts a row at the end of the table model */
     /*public void insertRow(){      
          int length = getRowCount();
          for (int i=0; i<length ; i++)
          //just add blank string values in this instance but your
          //code will initialise a default object no doubt
          data.addElement("");
          //baseData is the vector containing all your row vectors
          fireTableDataChanged();
     public void addRow()
          addRow(data);
          fireTableDataChanged();
     * Method updateQueue.
     * This method will allow us to update the queues with the latest
     * and greatest information of what messages got added or are
     * on the queue and what time the messages occurred.
     * @param monitorMsgObject
     public synchronized void updateQueue(MonitorMessageObject monitorMsgObject)
     public static void main(String[] args)
/*********** THis is my main gui class that will has a TableListener and ActionHandler inner - classes within *************/
package com.ibm.esup.agent.dataqmonitor;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.IOException;
import java.util.Vector;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.*;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.DefaultTableModel;
import com.ibm.as400.access.AS400;
import com.ibm.as400.access.AS400Exception;
import com.ibm.as400.access.AS400SecurityException;
* @author garbersb *
* This will allow the user to sign onto a particular system
* with a valid user id and password.
public class SignOn extends JFrame
     /** Label for the system name. */
     private JLabel labelSystemName;
     /** Label for the user name. */
     private JLabel labelUserName;
     /** Label for the password. */
     private JLabel labelPassword;
     /** Label for input queue. */
     private JLabel labelInputQueue;
     /** Label for output queue. */
     private JLabel labelOutputQueue;
     /** Text Field for the system name. */
     private JTextField textFieldSystemName;
     /** Text Field for the user name. */
     private JTextField textFieldUserName;
     /** Text Field for the password. */
     private JPasswordField textFieldPassword;
     /** Text Field for the input queue. */
     private JTextField textFieldInputQueue;
     /** Text Field for the output queue. */
     private JTextField textFieldOutputQueue;
     /** Button that will allow the user to submit. */
     private JButton buttonSubmit;
     /** String that will be used for the system name,
     * user name and password. */
     private String systemName, userName, password, inputQueue, outputQueue;
     /** Label for the input table where different queues
     * can be entered. */
     private JLabel labelQueueInput = null;
     /** One Column table where users can enter different
     * queues that they want to view. */
     private JTable tableQueueInput = null;
     /** Scroll pane that will be used to put the
     * table inside of it. */
     private JScrollPane scrollPaneQueueInput = null;
     /** Label for the interval time that they want to
     * check these different queues. */
     private JLabel labelIntervalCheck = null;
     /** Table panel */
     private JPanel panelTable = null;
     /** Text Field where users can enter a number
     * that will end up being the time that this application
     * will check thes queues. (This is in milli-seconds)
     * For example if a user wants to check the queue every 5 minutes
     * they would enter 60000 within this text field. */
     private JTextField textFieldIntveralCheck = null;
     /** Table Model Input Queue */
     private QueueTableModel tableModelInputQueue = null;
     /** AS400 system object that will be used to sign
     * onto an iSeries system. */
     private AS400 system;
     * Method loadGui.
     * This will load the Sign On Frame and will allow the
     * user to enter the information within the Text Field
     * or specify an xml file that has TCP information already
     * in it.
     public void loadGui()
          //Set the Title
          this.setTitle("Sign On to iSeries System");
          Container contentPane = this.getContentPane();
          GridBagLayout gbl = new GridBagLayout();
          GridBagConstraints gbc = new GridBagConstraints();
          gbc.insets = new Insets(10, 10, 10, 10);
          gbc.fill = GridBagConstraints.EAST;
          contentPane.setLayout(gbl);
          labelSystemName = new JLabel("System Name");
          gbc.gridx = 0;
          gbc.gridy = 1;
          gbl.setConstraints(labelSystemName, gbc);
          contentPane.add(labelSystemName);
          textFieldSystemName = new JTextField();
          textFieldSystemName.setColumns(20);
          gbc.gridx = 1;
          gbc.gridy = 1;
          gbc.gridwidth = 4;
          gbl.setConstraints(textFieldSystemName, gbc);
          contentPane.add(textFieldSystemName);
          labelUserName = new JLabel("User Name");
          gbc.gridx = 0;
          gbc.gridy = 2;
          gbl.setConstraints(labelUserName, gbc);
          contentPane.add(labelUserName);
          textFieldUserName = new JTextField();
          textFieldUserName.setColumns(20);
          gbc.gridx = 1;
          gbc.gridy = 2;
          gbc.gridwidth = 4;
          gbl.setConstraints(textFieldUserName, gbc);
          contentPane.add(textFieldUserName);
          labelPassword = new JLabel("Password");
          gbc.gridx = 0;
          gbc.gridy = 3;
          gbl.setConstraints(labelPassword, gbc);
          contentPane.add(labelPassword);
          textFieldPassword = new JPasswordField();
          textFieldPassword.setColumns(20);
          gbc.gridx = 1;
          gbc.gridy = 3;
          gbc.gridwidth = 4;
          gbl.setConstraints(textFieldPassword, gbc);
          contentPane.add(textFieldPassword);
/*          labelInputQueue = new JLabel("Interval Check");
          gbc.gridx = 0;
          gbc.gridy = 4;
          gbl.setConstraints(labelInputQueue, gbc);
          contentPane.add(labelInputQueue);
          textFieldInputQueue = new JTextField();
          textFieldInputQueue.setColumns(20);
          gbc.gridx = 1;
          gbc.gridy = 4;
          gbc.gridwidth = 4;
          gbl.setConstraints(textFieldInputQueue, gbc);
          contentPane.add(textFieldInputQueue);
          labelInputQueue = new JLabel("Input Queue");
          gbc.gridx = 0;
          gbc.gridy = 4;
          gbl.setConstraints(labelInputQueue, gbc);
          contentPane.add(labelInputQueue);
          textFieldInputQueue = new JTextField();
          textFieldInputQueue.setColumns(20);
          gbc.gridx = 1;
          gbc.gridy = 4;
          gbc.gridwidth = 4;
          gbl.setConstraints(textFieldInputQueue, gbc);
          contentPane.add(textFieldInputQueue);
          labelOutputQueue = new JLabel("Output Queue");
          gbc.gridx = 0;
          gbc.gridy = 5;
          gbl.setConstraints(labelOutputQueue, gbc);
          contentPane.add(labelOutputQueue);
          textFieldOutputQueue = new JTextField();
          textFieldOutputQueue.setColumns(20);
          gbc.gridx = 1;
          gbc.gridy = 5;
          gbc.gridwidth = 4;
          gbl.setConstraints(textFieldOutputQueue, gbc);
          contentPane.add(textFieldOutputQueue);
          labelQueueInput = new JLabel("Input Queues");
          gbc.gridx = 0;
          gbc.gridy = 6;
          gbl.setConstraints(labelQueueInput, gbc);
          contentPane.add(labelQueueInput);
          tableQueueInput= new JTable();
          scrollPaneQueueInput = new JScrollPane(tableQueueInput);
          Dimension tableQueueInputDimension = new Dimension(220, 100);
          scrollPaneQueueInput.setPreferredSize(tableQueueInputDimension);
          gbc.gridx = 1;
          gbc.gridy = 6;
          gbc.gridwidth = 4;
          gbl.setConstraints(scrollPaneQueueInput, gbc);
          contentPane.add(scrollPaneQueueInput);
          //Setting up the table model input queue.
          tableModelInputQueue = new QueueTableModel();
          tableQueueInput.setModel(tableModelInputQueue);
          TableListener tableListener = new TableListener();
          tableModelInputQueue.addTableModelListener(tableListener);          
          buttonSubmit = new JButton("Submit");
          gbc.gridx = 0;
          gbc.gridy = 7;
          gbl.setConstraints(buttonSubmit, gbc);
          contentPane.add(buttonSubmit);
          RunHandler handler = new RunHandler();
          buttonSubmit.addActionListener(handler);
          //For now we will set the text in the
          //input and output queue for the Analyzer
          //Agent.
          textFieldInputQueue.setText("/qsys.lib/qesp.lib/anz_input.dtaq");
          textFieldOutputQueue.setText("/qsys.lib/qesp.lib/anz_output.dtaq");
     private class TableListener implements TableModelListener {
public TableListener() {
public void tableChanged(TableModelEvent e) {
int row = e.getFirstRow();
int column = e.getColumn();
String columnName = tableModelInputQueue.getColumnName(column);
Object data = tableModelInputQueue.getValueAt(row, column);
System.out.println("row " + row + "column " + column);
if (row == 4) {
     tableModelInputQueue.addRow();
          * @author garbersb
          * This will end up creating the System object
     * by getting the system name, user id and
     * password from the Text Field values.
     private class RunHandler implements ActionListener
          * @see java.awt.event.ActionListener#actionPerformed(ActionEvent)
          * When the submit button is selected it will cause the
          * action event to do something.
          public void actionPerformed(ActionEvent e)
               if (e.getSource() == buttonSubmit)
                    //here we will get the system name, user name
                    //and password.
                    systemName = textFieldSystemName.getText().trim();
                    userName = textFieldUserName.getText().trim();
                    char[] passwordCharArray = textFieldPassword.getPassword();
                    String password = new String(passwordCharArray);
                    inputQueue = textFieldInputQueue.getText().trim();
                    outputQueue = textFieldOutputQueue.getText().trim();
                    //here we will create an AS400 Object.
                    try {
                         system = new AS400(systemName, userName, password);
                         system.connectService(AS400.SIGNON);
                    catch (AS400SecurityException as400e) {
                         as400e.toString();
                    catch (IOException ioe) {
                         ioe.toString();
                    //Going to hide the Sign On window now.
                    setVisible(false);
                    //Now we will load the class that monitors
                    //the input and output queues.
                    MonitorDataQueueGui monitorGui = new MonitorDataQueueGui(system, inputQueue, outputQueue);
                    monitorGui.addGui();
                    monitorGui.show();
                    monitorGui.pack();
     public static void main(String[] args)
          SignOn signOn = new SignOn();
          signOn.loadGui();
          signOn.setSize(400, 400);
          signOn.show();
          signOn.pack();
          signOn.setVisible(true);
          signOn.addWindowListener(new WindowAdapter()
               public void windowClosing(WindowEvent e)
                    System.exit(0);
}

Answer 1

Well....I ended up using insertRow with the following code within the method.
     public void insertRow(){      
          numRows += 1;
          fireTableDataChanged();
I changed my method for the getRowCount to the following;
     * @see javax.swing.table.TableModel#getRowCount()
     public synchronized int getRowCount()
          if (numRows < START_NUM_ROWS)
               numRows = START_NUM_ROWS;
               return START_NUM_ROWS;
          else
               return numRows;
Since I am not scared of deleting rows I think this is fine....After I did this within my SignOn class I have the following within my TableListener inner class.
     private class TableListener implements TableModelListener {
public TableListener() {
public void tableChanged(TableModelEvent e) {
int row = e.getFirstRow();
int column = e.getColumn();
String columnName = tableModelInputQueue.getColumnName(column);
Object data = tableModelInputQueue.getValueAt(row, column);
System.out.println("row " + row + "column " + column);
if (row > 4) {
     tableModelInputQueue.insertRow();
I am wondering if this is the best way to do it. It seems to work now without a problem but like I said...I am wondering if this is the best thing to do. Any advise would be greatly appreciated and I really do appreciate the advise that has already been given to me.