jTable column header (title) isn't visible after applying sidebar

[David Phirtskhalava]

hello,
i created normal jframe form and it contains jtable
but my jtable has 23 column and i decided to make sidebar but after i did sidebar i lost my column header
some way to view again my jtable column headers ?
this is my code

package tracia;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;
import net.proteanit.sql.DbUtils;



public class frmTraList extends javax.swing.JFrame {

   
    public frmTraList() {
        initComponents();
    }
        Connection conn = null;
        ResultSet rs = null;
        PreparedStatement pst = null;
        
        
    
           
    private void UpdateJTable(){
    String sql = "select id, Nome_cliente, provenienza_ddt, numero_ddt, data_ddt, peso_dic, peso_ver, data_lavorazione, numero_pezzi, tipo_prosciutto, tipo_lavorazione, lotto_cliente, data_confezione, scadenza, lotto_buste, lotto_stagnola, lotto_pellicola, lotto_ganci, consegna_merce, Operatore, data_registrazione, aggiornato_da, Ultima_aggiornamento  from trac";
    try{
        pst = conn.prepareStatement(sql);
        rs = pst.executeQuery();
        jTable1.setModel(DbUtils.resultSetToTableModel(rs));
    }
    catch (Exception e){
       
    }
}
   
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        scrollPane1 = new java.awt.ScrollPane();
        jTable1 = new javax.swing.JTable();

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
        setPreferredSize(new java.awt.Dimension(1300, 720));
        addWindowListener(new java.awt.event.WindowAdapter() {
            public void windowOpened(java.awt.event.WindowEvent evt) {
                formWindowOpened(evt);
            }
        });

        scrollPane1.setMaximumSize(new java.awt.Dimension(1280, 680));

        jTable1.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {
                {null, null, null, null},
                {null, null, null, null},
                {null, null, null, null},
                {null, null, null, null}
            },
            new String [] {
                "ID", "Nome Cliente", "Provenienza DDT", "Numero DDT", "Data DDT", "Peso Dichiarato", "Peso Verifocato", "Data di Lavorazione", "Numero Pezzo", "Tipo Prosciutto", "Tipo Lavorazione", "Lotto Cliente", "Data di Confezione", "Scadenza", "Lotto Buste", "Lotto Stagnola", "Lotto Pellicola", "Lotto Ganci", "Consegna Merce", "Compilato", "Data di Registrazione", "Aggiornato Da", "Ultima Aggiornamento"

            }
        ));
        jTable1.setAutoResizeMode(javax.swing.JTable.AUTO_RESIZE_OFF);
        jTable1.setMaximumSize(new java.awt.Dimension(2147483647, 2147483647));
        jTable1.setMinimumSize(new java.awt.Dimension(2225, 680));
        jTable1.setPreferredSize(new java.awt.Dimension(2225, 680));
        scrollPane1.add(jTable1);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(scrollPane1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 1280, javax.swing.GroupLayout.PREFERRED_SIZE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(scrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 680, javax.swing.GroupLayout.PREFERRED_SIZE)
        );

        pack();
        setLocationRelativeTo(null);
    }// </editor-fold>                        

    /**
     *
     * @param table
     * @param tablePreferredWidth
     * @param percentages
     */
  
    
    
    int[] columnsWidth = {
                25,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100,100
        };
    private void formWindowOpened(java.awt.event.WindowEvent evt) {                                  
        conn = mysqlconnect.ConnectDb();
         UpdateJTable();
     jTable1.setRowHeight(30);
     jTable1.setRowHeight(100, 250);
    TableColumnModel columnModel = jTable1.getColumnModel();
    
     

      
        int i = 0;
        for (int width : columnsWidth) {
            TableColumn column = jTable1.getColumnModel().getColumn(i++);
            column.setMinWidth(width);
            column.setMaxWidth(width);
            column.setPreferredWidth(width);
        }

       
    
    }                                 

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(frmTraList.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(frmTraList.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(frmTraList.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(frmTraList.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new frmTraList().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JTable jTable1;
    private java.awt.ScrollPane scrollPane1;
    // End of variables declaration                   
}

[Rob Camick]

scrollPane1.add(jTable1);  

Don't add any component to the scrollpane. Instead you need to add the component to the viewport of the scrollpane:

scrollPane1.setViewportView(jTable1);  

Or another way to do this is the specify the table when you create the scrollpane:

JScrollPane scrollPane = new JScrollPane( table );