Java programming help

package aaa;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JPanel;

import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;

import javax.swing.WindowConstants;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableModel;
import java.sql.*;
import java.util.Vector;

/**
* This code was edited or generated using CloudGarden's Jigloo
* SWT/Swing GUI Builder, which is free for non-commercial
* use. If Jigloo is being used commercially (ie, by a corporation,
* company or business for any purpose whatever) then you
* should purchase a license for each developer using Jigloo.
* Please visit www.cloudgarden.com for details.
* Use of Jigloo implies acceptance of these licensing terms.
* A COMMERCIAL LICENSE HAS NOT BEEN PURCHASED FOR
* THIS MACHINE, SO JIGLOO OR THIS CODE CANNOT BE USED
* LEGALLY FOR ANY CORPORATE OR COMMERCIAL PURPOSE.
*/
public class StudJFrame extends javax.swing.JFrame {
	private JPanel jPanel1;
	private JScrollPane jScrollPane1;
	private JTable jTableStudents;
	private JButton jButtonSearch;
	private JComboBox jComboBoxGender;
	private JPanel jPanel5;
	private JPanel jPanel4;
	private JPanel jPanel3;
	private JLabel jLabel2;
	private JTextField jTextFieldSurname;
	private JLabel jLabel1;
	private JPanel jPanel2;
    Connection con= null;
    
	/**
	* Auto-generated main method to display this JFrame
	*/
	public static void main(String[] args) {
		StudJFrame inst = new StudJFrame();
	
		inst.setVisible(true);
	}
	
	public StudJFrame() {
		super();
		try {
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			con = DriverManager.getConnection("jdbc:odbc:StudDBDS","","");
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		initGUI();
	}
	
	private void initGUI() {
		try {
			BorderLayout thisLayout = new BorderLayout();
			thisLayout.setVgap(20);
			getContentPane().setLayout(thisLayout);
			setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
			{
				jPanel2 = new JPanel();
				GridLayout jPanel2Layout = new GridLayout(3, 1);
				jPanel2Layout.setHgap(5);
				jPanel2Layout.setVgap(5);
				jPanel2Layout.setColumns(1);
				jPanel2Layout.setRows(3);
				jPanel2.setLayout(jPanel2Layout);
				getContentPane().add(jPanel2, BorderLayout.NORTH);
				jPanel2.setPreferredSize(new java.awt.Dimension(584, 94));
				{
					jPanel3 = new JPanel();
					FlowLayout jPanel3Layout = new FlowLayout();
					jPanel3Layout.setAlignment(FlowLayout.LEFT);
					jPanel3.setLayout(jPanel3Layout);
					jPanel2.add(jPanel3);
					{
						jLabel1 = new JLabel();
						jPanel3.add(jLabel1);
						jLabel1.setText("Surname");
					}
					{
						jTextFieldSurname = new JTextField();
						jPanel3.add(jTextFieldSurname);
						jTextFieldSurname.setPreferredSize(new java.awt.Dimension(289, 23));
					}
				}
				{
					jPanel4 = new JPanel();
					FlowLayout jPanel4Layout = new FlowLayout();
					jPanel4Layout.setAlignment(FlowLayout.LEFT);
					jPanel4.setLayout(jPanel4Layout);
					jPanel2.add(jPanel4);
					{
						jLabel2 = new JLabel();
						jPanel4.add(jLabel2);
						jLabel2.setText("   Gender");
					}
					{
						
						jComboBoxGender = new JComboBox();
						Statement stmt = con.createStatement();
						ResultSet rs = stmt.executeQuery("Select * From Gender");
						jComboBoxGender.addItem("All");
						while (rs.next())
						{
							jComboBoxGender.addItem(rs.getString(2));
						}
						
						jPanel4.add(jComboBoxGender);
					}
				}
				{
					jPanel5 = new JPanel();
					jPanel2.add(jPanel5);
					{
						jButtonSearch = new JButton();
						jPanel5.add(jButtonSearch);
						jButtonSearch.setText("Search");
						jButtonSearch.addActionListener(new ActionListener() {
							public void actionPerformed(ActionEvent evt) {
								jButtonSearchActionPerformed(evt);
							}
						});
					}
				}
			}
			{
				jPanel1 = new JPanel();
				BorderLayout jPanel1Layout = new BorderLayout();
				jPanel1.setLayout(jPanel1Layout);
				getContentPane().add(jPanel1, BorderLayout.CENTER);
				{
					jScrollPane1 = new JScrollPane();
					jPanel1.add(jScrollPane1, BorderLayout.CENTER);
					{
						String[] header = {"Surname","Name","Group","Gender" };
						jTableStudentsModel = new DefaultTableModel(header,0);
						jTableStudents = new JTable();
						jScrollPane1.setViewportView(jTableStudents);
						jTableStudents.setModel(jTableStudentsModel);
					}
				}
			}
			pack();
			setSize(600, 450);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	DefaultTableModel jTableStudentsModel  = null;
	private void jButtonSearchActionPerformed(ActionEvent evt) {
		String gender = jComboBoxGender.getSelectedItem().toString();
		String query = "Select Surname,FName,Groupe,Gender.GName FROM Student,Gender"+
		" WHERE Student.GenderID = Gender.ID and Surname LIKE ? ";
		if (!gender.equals("All"))
				{
					query +="and Gender.GName = ?";
				}
				
		
		try
	    {
	      PreparedStatement ps= con.prepareStatement(query);
	      

	      ps.setString(1, jTextFieldSurname.getText()+"%");
	      if (!gender.equals("All"))   ps.setString(2,gender );
	      
	      ResultSet rs = ps.executeQuery();
	      int n= jTableStudentsModel.getRowCount();
	      for (int i = 0; i < n; i++) {
	    	  jTableStudentsModel.removeRow(i);
	      }
	      int i=0;
	      while (rs.next() )
	      {
	        Vector vec= new Vector();
	        vec.add(rs.getString(1));
	        vec.add(rs.getString(2));
	        vec.add(rs.getString(3));
	        vec.add(rs.getString(4));
	        jTableStudentsModel.addRow(vec);
	      }
	      jTableStudents.repaint();
	    }
	    catch (Exception ex) {
	    		int i= 1;
	    		i++;
	    }

		
		
	}

}