Help with these Exceptions!

Question

Hello All,
when the code below is run and I select a table name that starts with the number 0 I get a Eception, which is fine but when I click back into the combobox where I have the Table name that sarts with the number 0,
it Thows that Exception again. How can I get my code to only thow that exception once?
Someone suggested to use the getId() for the Action event will do this. I have tried to find out how to use this but was unsucessfull. Please could someone help me?
Thanks
Dave
import javax.swing.*;
import javax.swing.table.*;
import java.awt.event.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;
public class ComboBoxTable{
static Connection conn2;
   static DatabaseMetaData DMD;
   static JComboBox group = new JComboBox();
   static JComboBox groupList = new JComboBox();
  public static void main(String[] args) {
try  {
          // Load the database driver
        Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver" ) ;
        conn2 = DriverManager.getConnection( "jdbc:odbc:myProject") ;
        DMD=conn2 .getMetaData();
        ResultSet rs=DMD.getTables(null,null,null,new String[]{"TABLE"});
        while(rs.next()) {
          group.addItem((String)rs.getString(3));
        rs.close() ;
     } catch (SQLException se ) {
        System.out.println( "SQL Exception: " + se ) ;
     } catch (Exception e ) {
        System.out.println( e ) ;
     group.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e)  {
          String tbl = (String)group.getSelectedItem();
          try {
                Statement st=conn2.createStatement();
             st.execute("SELECT * FROM "+tbl+" WHERE 1=0");
             ResultSet rs=st.getResultSet();
             ResultSetMetaData md=rs.getMetaData();
             groupList.removeAllItems();
             for (int i=1;i<=md.getColumnCount();i++) {
               groupList.addItem(md.getColumnName(i));
             st.close() ;
          } catch (SQLException se ) {
             System.out.println( "SQL Exception: " + se ) ;
          } catch (Exception ex ) {
             System.out.println( ex ) ;
int j=10;
      String[][] data = new String[j][2];
      for (int k=0; k<j; k++){
         String[] row = {"",""};
         data[k] = row;
    String[] colNames = {"Column A", "Column B"};
    JTextField jtf = new JTextField();
    JTable tbl = new JTable(data, colNames);
// Create the combo box editor
    DefaultCellEditor editor = new DefaultCellEditor(groupList);
// ADDED IN MY ATTEMPT TO HAVE TO COLUMNS WITH COMBOBOXES
    DefaultCellEditor editor2 = new DefaultCellEditor(group);
// Assign the editor to the second column
    TableColumnModel tcm = tbl.getColumnModel();
    tcm.getColumn(0).setCellEditor(editor2);
// ADDED
    tcm.getColumn(1).setCellEditor(editor);
// Set column widths
    tcm.getColumn(0).setPreferredWidth(200);
    tcm.getColumn(1).setPreferredWidth(100);
// Set row heighht
    tbl.setRowHeight(20);
    tbl.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
    tbl.setPreferredScrollableViewportSize(tbl.getPreferredSize());
     JFrame f = new JFrame("ComboBoxDemo");
    f.getContentPane().add(new JScrollPane(tbl), "Center");
    f.pack();
    f.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent evt) {
         System.exit(0);
    f.setVisible(true);
}

Answer 1

If you can predict an exception with such certainty, you should put some sanity checking in your code to prevent the the exception from ever occurring.