Erro ao tentar salvar no Banco Mysql - NullPointerException

Alo pessoal, boa tarde

tenho uma classe chamada AbrirChamado.java com alguns jcomboBox´s e JtextField´s e ao apertar o botão para salvar no banco (MySQL) dá o seguinte erro:
[color=red]Exception in thread “AWT-EventQueue-0” java.lang.NullPointerException[/color=red]

segue abaixo detalhes:

AbrirChamado.java

package cadastros;
import java.sql.SQLException;
import javax.swing.*;
import utilitarios.Datas;
import utilitarios.Mail;
import utilitarios.conexao;
import javax.swing.table.DefaultTableModel;
import utilitarios.conexao;
import java.io.File;
/*
 * AbrirChamado.java
  * Created on 11 de Agosto de 2008, 16:51
 * @author  luizpaulo
 */
public class AbrirChamado extends javax.swing.JFrame {
        Datas mostra_data;
        conexao con_setor;
        conexao con_usuario;
        conexao con_usuario2;
        conexao con_usuario3;
        conexao con_ocorrencias;
        String codSetor;
        int inicia_combo =0;
        /** Creates new form AbrirChamado */
    public AbrirChamado() {
        initComponents();       
        mostra_data = new Datas(); 
        mostra_data.le_data();
        mostra_data.le_hora();
        lbData.setText(mostra_data.dia+"/"+mostra_data.mes+"/"+mostra_data.ano+ " - " +mostra_data.hora);
        con_setor = new conexao();       
        con_setor.conecta();
        con_setor.executeSQL("select * from setor");        
        try
        {
            while (con_setor.resultset.next())                
                jcbSetor.addItem(con_setor.resultset.getString("st_nome"));                            
        }
        catch(SQLException erro)
        {
        
        }   
        
    }
    
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">                          
    private void initComponents() {
        jButton2 = new javax.swing.JButton();
        jButton3 = new javax.swing.JButton();
        jPanel1 = new javax.swing.JPanel();
        jcbSetor = new javax.swing.JComboBox();
        jLabel3 = new javax.swing.JLabel();
        jLabel1 = new javax.swing.JLabel();
        jLabel15 = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        jScrollPane1 = new javax.swing.JScrollPane();
        jtaDescricaoProblema = new javax.swing.JTextArea();
        jLabel2 = new javax.swing.JLabel();
        jLabel5 = new javax.swing.JLabel();
        tfEmail = new javax.swing.JTextField();
        jcbContato = new javax.swing.JComboBox();
        jLabel17 = new javax.swing.JLabel();
        tfRamal = new javax.swing.JTextField();
        jcbProblema = new javax.swing.JComboBox();
        jPanel2 = new javax.swing.JPanel();
        jLabel12 = new javax.swing.JLabel();
        jLabel6 = new javax.swing.JLabel();
        lbSetor = new javax.swing.JLabel();
        jLabel8 = new javax.swing.JLabel();
        lbData = new javax.swing.JLabel();
        jLabel9 = new javax.swing.JLabel();
        jLabel10 = new javax.swing.JLabel();
        jLabel14 = new javax.swing.JLabel();
        lbEmail = new javax.swing.JLabel();
        lbRamal = new javax.swing.JLabel();
        jLabel13 = new javax.swing.JLabel();
        jLabel7 = new javax.swing.JLabel();
        lbUsuario = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
        setTitle("Abertura de Ocorr\u00eancias");
        setResizable(false);
        jButton2.setIcon(new javax.swing.ImageIcon("C:\\ahimor\\chamados\\imagens\\gravar_registro.gif"));
        jButton2.setText("Abrir Chamado");
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
            }
        });

        jButton3.setIcon(new javax.swing.ImageIcon("C:\\ahimor\\chamados\\imagens\\delete.gif"));
        jButton3.setText("Cancelar");
        jButton3.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mouseClicked(java.awt.event.MouseEvent evt) {
                jButton3MouseClicked(evt);
            }
        });

        jPanel1.setBackground(new java.awt.Color(255, 255, 255));
        jcbSetor.setToolTipText("Setor");
        jcbSetor.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jcbSetorActionPerformed(evt);
            }
        });

        jLabel3.setFont(new java.awt.Font("Tahoma", 1, 14));
        jLabel3.setForeground(new java.awt.Color(0, 102, 0));
        jLabel3.setText("Solicita\u00e7\u00e3o:");

        jLabel1.setText("\u00c1rea Respons\u00e1vel:");

        jLabel15.setText("Descri\u00e7\u00e3o do Problema:");

        jLabel4.setText("Contato:");

        jtaDescricaoProblema.setColumns(20);
        jtaDescricaoProblema.setRows(5);
        jScrollPane1.setViewportView(jtaDescricaoProblema);

        jLabel2.setText("Problema:");

        jLabel5.setText("Email:");

        jcbContato.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jcbContatoActionPerformed(evt);
            }
        });

        jLabel17.setText("Ramal:");

        jcbProblema.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Qualquer" }));
        jcbProblema.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jcbProblemaActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel3)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addGap(3, 3, 3)
                                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                                    .addComponent(jLabel1)
                                    .addComponent(jLabel15)))
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addGap(68, 68, 68)
                                .addComponent(jLabel4)))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addComponent(jcbContato, javax.swing.GroupLayout.PREFERRED_SIZE, 236, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addGap(20, 20, 20)
                                .addComponent(jLabel5)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(tfEmail, javax.swing.GroupLayout.DEFAULT_SIZE, 309, Short.MAX_VALUE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(jLabel17)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(tfRamal, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE))
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addComponent(jcbSetor, javax.swing.GroupLayout.PREFERRED_SIZE, 220, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(jLabel2)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(jcbProblema, 0, 399, Short.MAX_VALUE))
                            .addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 675, Short.MAX_VALUE))))
                .addContainerGap())
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel3)
                .addGap(34, 34, 34)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(jcbSetor, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel1)
                    .addComponent(jcbProblema, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel15)
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(tfRamal, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel17)
                    .addComponent(jLabel5)
                    .addComponent(jcbContato, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(tfEmail, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jLabel4))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        jPanel2.setBackground(new java.awt.Color(255, 255, 255));
        jLabel12.setFont(new java.awt.Font("Tahoma", 1, 14));
        jLabel12.setForeground(new java.awt.Color(0, 102, 0));
        jLabel12.setText("Solicitante:");

        jLabel6.setText("Setor:");

        lbSetor.setText("jLabel13");

        jLabel8.setText("Data de Abertura:");

        lbData.setText("jLabel13");

        jLabel9.setText("Status:");

        jLabel10.setText("Aguardando atendimento");

        jLabel14.setText("E-mail:");

        lbEmail.setText("jLabel15");

        lbRamal.setText("jLabel14");

        jLabel13.setText("RAMAL:");

        jLabel7.setText("Operador:");

        lbUsuario.setText("jLabel12");

        javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
        jPanel2.setLayout(jPanel2Layout);
        jPanel2Layout.setHorizontalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel12)
                    .addGroup(jPanel2Layout.createSequentialGroup()
                        .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jLabel9, javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(jLabel6, javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(jLabel8, javax.swing.GroupLayout.Alignment.TRAILING))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(lbData)
                            .addComponent(lbSetor)
                            .addComponent(jLabel10))
                        .addGap(142, 142, 142)
                        .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jLabel7)
                            .addGroup(jPanel2Layout.createSequentialGroup()
                                .addGap(10, 10, 10)
                                .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                                    .addComponent(jLabel14)
                                    .addComponent(jLabel13))))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(lbUsuario)
                            .addComponent(lbRamal, javax.swing.GroupLayout.PREFERRED_SIZE, 53, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(lbEmail, javax.swing.GroupLayout.PREFERRED_SIZE, 240, javax.swing.GroupLayout.PREFERRED_SIZE))))
                .addContainerGap(150, Short.MAX_VALUE))
        );
        jPanel2Layout.setVerticalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel12)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel6)
                    .addComponent(lbSetor)
                    .addComponent(jLabel7)
                    .addComponent(lbUsuario))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel8)
                    .addComponent(lbData)
                    .addComponent(jLabel13)
                    .addComponent(lbRamal))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel14)
                    .addComponent(lbEmail)
                    .addComponent(jLabel9)
                    .addComponent(jLabel10))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(jPanel1, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(jPanel2, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jButton3)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jButton2)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(14, 14, 14)
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jButton3)
                    .addComponent(jButton2))
                .addContainerGap())
        );
        pack();
        java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
        java.awt.Dimension dialogSize = getSize();
        setLocation((screenSize.width-dialogSize.width)/2,(screenSize.height-dialogSize.height)/2);
    }// </editor-fold>                        

    private void jcbProblemaActionPerformed(java.awt.event.ActionEvent evt) {                                            
              
    }                                           

    private void jcbContatoActionPerformed(java.awt.event.ActionEvent evt) {                                           
     
            try
            {              
              con_usuario2 = new conexao();
              con_usuario2.conecta();
              atualiza_tfEmail();              
            }
            catch(Exception erro)
            {
                 //JOptionPane.showMessageDialog(null, "Não conseguiu localizar via Seleção no JComboBox, erro = "+erro);
            }
    }                                          
    private void jcbSetorActionPerformed(java.awt.event.ActionEvent evt) {                                         
        if (inicia_combo == 1)
        {    
            try
            {              
              con_usuario = new conexao();
              con_usuario.conecta();
              atualiza_combo_box_contato();             
              pega_cod_setor();
              atualiza_jcbProblema();  
            }
            catch(Exception erro)
            {
                 //JOptionPane.showMessageDialog(null, "Não conseguiu localizar via Seleção no JComboBox, erro = "+erro);
            }
        }
        inicia_combo=1;
    }                                        

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
     try
     {    
               //---------- começa o procedimento gravação no banco-------------
               String sqlinsert ="insert into ocorrencias (problema,descricao) values ('1','teste')";
               
               con_ocorrencias = new conexao();
               con_ocorrencias.statement.executeUpdate(sqlinsert);               
               //---------- começa o procedimento de envio de email-------------
               Mail MyEmail = new Mail();                
               MyEmail.setRemetente("xxxxx@xxxxxxxx.com.br");
               MyEmail.setDestinatario(tfEmail.getText());
               MyEmail.setAssunto("AVISO - Controle de Ocorrências - AHIMOR");
               String mensagem = "<HTML><font size='2' face='Verdana, Arial, Helvetica, sans-serif'><font color='006600'><strong>Sistema de Controle de Ocorrências - AHIMOR</strong></span><br /><font color='000000'>Foi aberto um novo chamado técnico para ser atendido pela &aacute;rea <strong>"+jcbSetor.getSelectedItem()+"</strong>.<br />O n&uacute;mero do chamado &eacute; <span class='style3'>tal</span><br /><strong>Problema:</strong> "+jcbProblema.getSelectedItem()+"<br /><strong>Contato:</strong> "+lbUsuario.getText()+"<br /><strong>Setor:</strong> "+lbSetor.getText()+"<br /><strong>Ramal:</strong> "+lbRamal.getText()+"</font></HTML>";
               MyEmail.setMensagem(mensagem); 
               MyEmail.enviarMensagem();
               dispose();
               JOptionPane.showMessageDialog(null,"Ocorrência Criada com Sucesso!\r\nUm email foi enviado para " +tfEmail.getText()+"!");                                             
               desconecta_BD();
     }
     catch (SQLException erro)
     {
	erro.printStackTrace();             
     }  
               
    }                                        

    private void jButton3MouseClicked(java.awt.event.MouseEvent evt) {                                      
              dispose();// TODO add your handling code here:
    }                                     
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new AbrirChamado().setVisible(true);
            }
        });
    }
     
    
    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton2;
    private javax.swing.JButton jButton3;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel10;
    private javax.swing.JLabel jLabel12;
    private javax.swing.JLabel jLabel13;
    private javax.swing.JLabel jLabel14;
    private javax.swing.JLabel jLabel15;
    private javax.swing.JLabel jLabel17;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel jLabel6;
    private javax.swing.JLabel jLabel7;
    private javax.swing.JLabel jLabel8;
    private javax.swing.JLabel jLabel9;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JComboBox jcbContato;
    private javax.swing.JComboBox jcbProblema;
    private javax.swing.JComboBox jcbSetor;
    private javax.swing.JTextArea jtaDescricaoProblema;
    private javax.swing.JLabel lbData;
    public static javax.swing.JLabel lbEmail;
    public static javax.swing.JLabel lbRamal;
    public static javax.swing.JLabel lbSetor;
    public static javax.swing.JLabel lbUsuario;
    public static javax.swing.JTextField tfEmail;
    private javax.swing.JTextField tfRamal;
    // End of variables declaration                   
    
   
    
    public void atualiza_tfEmail()
    // este processo atualiza os campos de email e ramal
    {
            try
            {   
                //JOptionPane.showMessageDialog(null,"select * from login Where log_nome like '"+jcbContato.getSelectedItem()+"'");
                con_usuario2.executeSQL("select * from login Where log_nome like '"+jcbContato.getSelectedItem()+"' and log_setor like '"+jcbSetor.getSelectedItem()+"'");
                con_usuario2.resultset.next();
                tfEmail.setText(con_usuario2.resultset.getString("log_email"));  
                tfRamal.setText(con_usuario2.resultset.getString("log_ramal"));  
            }
            catch(SQLException erro)
            {
                //JOptionPane.showMessageDialog(null,"Não localizou dados "+erro);
            }
    }
    
    public void atualiza_combo_box_contato()
    {
        try
        {
          jcbContato.removeAllItems();       
          con_usuario.executeSQL("select * from login Where log_setor like '"+jcbSetor.getSelectedItem()+"' order by log_nome");                  
          while(con_usuario.resultset.next())            
              jcbContato.addItem(con_usuario.resultset.getString("log_nome"));              
        }
        
        catch(SQLException erro)
        {
            //JOptionPane.showMessageDialog(null,"Não localizou dados "+erro);
        }

    }
    
    public void atualiza_jcbProblema()
    {
        try
        { 
          con_usuario3 = new conexao();
          con_usuario3.conecta();                     
          jcbProblema.removeAllItems();                
          con_usuario3.executeSQL("select * from problemas Where prob_setor like '"+con_setor.resultset.getString("st_codigo")+"' order by problema");
          while(con_usuario3.resultset.next())            
              jcbProblema.addItem(con_usuario3.resultset.getString("problema"));                  
        }
        
        catch(SQLException erro)
        {
            //JOptionPane.showMessageDialog(null,"Não localizou dados "+erro);
        }

    }
    
    public void pega_cod_setor()
    {
        try
        {
            con_setor.executeSQL("select * from setor where st_nome like '"+jcbSetor.getSelectedItem() +"'");
            con_setor.resultset.next();
            //lbCodSetor.setText(con_setor.resultset.getString("st_codigo"));
            
        }
        
        catch(SQLException erro)
        {
            //JOptionPane.showMessageDialog(null,"Não localizou dados "+erro);
        }
}

ERRO:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
        at cadastros.AbrirChamado.jButton2ActionPerformed(AbrirChamado.java:376)
        at cadastros.AbrirChamado.access$000(AbrirChamado.java:15)
        at cadastros.AbrirChamado$1.actionPerformed(AbrirChamado.java:92)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:6038)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3260)
        at java.awt.Component.processEvent(Component.java:5803)
        at java.awt.Container.processEvent(Container.java:2058)
        at java.awt.Component.dispatchEventImpl(Component.java:4410)
        at java.awt.Container.dispatchEventImpl(Container.java:2116)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916)
        at java.awt.Container.dispatchEventImpl(Container.java:2102)
        at java.awt.Window.dispatchEventImpl(Window.java:2429)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)

Verifiquei em alguns foruns e alegaram que seria a conexao com BD, com a minha conexão consigo conectar, o problema está só em salvar. segue abaixo minha classe de conexao.

conexao.java

package utilitarios;
import java.sql.*;
import javax.swing.*;


public class conexao
{     
       final private String url = "jdbc:mysql://localhost/xxxxxxxx";
       final private String driver = "com.mysql.jdbc.Driver";
       final private String usuario = "xxxxxxxx";
       final private String senha = "xxxxx";
     
      
       private Connection conexao;
       public Statement statement;
       public ResultSet resultset;

       public boolean conecta()
       {
            boolean result = true;
            try 
            {
                Class.forName(driver);
                conexao = DriverManager.getConnection(url, usuario, senha);
                //JOptionPane.showMessageDialog(null,"conectou porra");
            }
            catch(ClassNotFoundException Driver) 
            {
               JOptionPane.showMessageDialog(null,"Driver não localizado: "+Driver);
               result = false;
            }
            catch(SQLException Fonte) 
            {
                JOptionPane.showMessageDialog(null,"Deu erro na conexão "+
                        "com a fonte de dados: "+Fonte);
                result = false;
            }
            return result; 
       }
       
       public void desconecta()
       {
            boolean result = true;
            try 
            {
                conexao.close();
                JOptionPane.showMessageDialog(null,"banco fechado");
            }
            catch(SQLException fecha) 
            {
                JOptionPane.showMessageDialog(null,"Não foi possivel "+
                        "fechar o banco de dados: "+fecha);
                result = false;
            }

       }
       
       public void executeSQL(String sql)
       {
            try 
            {
                statement = conexao.createStatement(
                        ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
                resultset = statement.executeQuery(sql);
            }
            catch(SQLException sqlex) 
            {
               JOptionPane.showMessageDialog(null,"Não foi possível "+
                       "executar o comando sql,"+sqlex+", o sql passado foi "+sql);
            }

       }

       
}        

Por favor pessoal, já estou há dois dias e nao consigo resolver este probleminha, deem um help ae …aa ja setei o mysql-connector-java-5.1.6-bin.jar no Libraries do Projeto, estou utilizando o NETBEANS

Abraços
LP

rapaz…se eu nao me engano o JComboBox trabalha com MVC…entao tu tens que passar ListDataModel…no contrutor dele…tenho um codigo desse em casa…qaundo chegar la passo pra tu…pra quem ja esperou 2 dias…se tu nao achar ate a noite eu mando pra tu de lá…

Bom Dia pessoal, ainda não consegui resolver este erro,

o problema é só quando grava no banco de dados
como meu banco ainda ta pequeno modifiquei de mysql pr access e o erro continuou , entao a possibilidade de ser prob no Mysql é zero.

o abelgomes falou que poderia ser Jcombobox, fiz um teste simples de inclusão sem utilização de jtextfiled e combobox:

String sqlinsert =“insert into ocorrencias (problema,descricao) values (‘1’,‘teste’)”;
con_ocorrencias.statement.executeUpdate(sqlinsert);

e o erro continuou…

Estou na guerra,
precisando de ajuda

Abraços
LP

pessoal criei outra classe, apenas com um botao salvar, e apresenta o mesmo erro, deem um help por favor!!

package cadastros;
import java.sql.SQLException;
import javax.swing.*;
import utilitarios.conexao;

public class teste extends javax.swing.JFrame {
    
    /** Creates new form teste */
    public teste() {
        initComponents();
    }
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">
    private void initComponents() {
        btn_Salvar = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        btn_Salvar.setText("salvar");
        btn_Salvar.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btn_SalvarActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(159, 159, 159)
                .addComponent(btn_Salvar)
                .addContainerGap(178, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap(142, Short.MAX_VALUE)
                .addComponent(btn_Salvar)
                .addGap(135, 135, 135))
        );
        pack();
    }// </editor-fold>

    private void btn_SalvarActionPerformed(java.awt.event.ActionEvent evt) {
             try
     {    
               //---------- começa o procedimento gravação no banco-------------
               String sqlinsert ="insert into ocorrencias (problema,descricao) values ('1','teste')";
               conexao con_ocorrencias;              
               con_ocorrencias = new conexao();
               con_ocorrencias.statement.executeUpdate(sqlinsert);               
               dispose();
               JOptionPane.showMessageDialog(null,"Ocorrência Criada com Sucesso!");                                                            
     }
     catch (SQLException erro)
     {
	erro.printStackTrace();             
     }  
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new teste().setVisible(true);
            }
        });
    }
    
    // Variables declaration - do not modify
    private javax.swing.JButton btn_Salvar;
    // End of variables declaration
    
}