Pessoal, venho novamente pedir a ajuda de voces para solucionar um erro que encontra na tela de login no projeto que estou desenvolvendo em desktop no netbeans, pois sou iniciante em java e não consegui resolver este erro. Aqui esta o codigo da tela de login:
package sisvenda;
import java.sql.*;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.swing.JOptionPane;
import sisvenda.conexao.Conexao;
/**
*
* @author João
*/
public class Login extends Usuarios {
Conexao banco_usuarios;
int conta = 0;
/** Creates new form Login */
public Login() {
initComponents();
banco_usuarios = new Conexao();
banco_usuarios.abrirBDConn();
}
/** 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=" Código Gerado ">
private void initComponents() {
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
tfLogin = new javax.swing.JTextField();
tfSenha = new javax.swing.JPasswordField();
btAcessar = new javax.swing.JButton();
jTextField1 = new javax.swing.JTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
setTitle("Tela de Login");
setBackground(new java.awt.Color(255, 255, 255));
setFont(new java.awt.Font("Arial", 0, 14));
jPanel1.setFont(new java.awt.Font("Arial", 0, 14));
jLabel1.setFont(new java.awt.Font("Arial", 0, 14));
jLabel1.setForeground(new java.awt.Color(0, 0, 153));
jLabel1.setText("Login :");
jLabel2.setFont(new java.awt.Font("Arial", 0, 14));
jLabel2.setForeground(new java.awt.Color(0, 0, 153));
jLabel2.setText("Senha :");
tfLogin.setFont(new java.awt.Font("Arial", 0, 14));
tfSenha.setFont(new java.awt.Font("Arial", 0, 14));
btAcessar.setFont(new java.awt.Font("Arial", 1, 14));
btAcessar.setForeground(new java.awt.Color(0, 0, 204));
btAcessar.setText("Acessar");
btAcessar.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btAcessarActionPerformed(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)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addComponent(jLabel1))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(tfSenha, javax.swing.GroupLayout.DEFAULT_SIZE, 85, Short.MAX_VALUE)
.addComponent(tfLogin, javax.swing.GroupLayout.DEFAULT_SIZE, 85, Short.MAX_VALUE))
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addComponent(btAcessar)
.addGap(27, 27, 27))))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1)
.addComponent(tfLogin, javax.swing.GroupLayout.PREFERRED_SIZE, 20, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(tfSenha, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(27, 27, 27)
.addComponent(btAcessar)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
jTextField1.setEditable(false);
jTextField1.setFont(new java.awt.Font("Arial", 1, 24));
jTextField1.setForeground(new java.awt.Color(204, 0, 0));
jTextField1.setHorizontalAlignment(javax.swing.JTextField.CENTER);
jTextField1.setText("Tela de Acesso ao Sistema de Vendas");
jTextField1.setBorder(null);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(435, 435, 435)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(287, 287, 287)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(295, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(67, 67, 67)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 44, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(162, 162, 162)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(350, Short.MAX_VALUE))
);
java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
setBounds((screenSize.width-1024)/2, (screenSize.height-780)/2, 1024, 780);
}// </editor-fold>
private void btAcessarActionPerformed(java.awt.event.ActionEvent evt) {
if ( tfLogin.getText().equals("") || tfSenha.getPassword().equals(""))
JOptionPane.showMessageDialog(null,"Os campos não podem ser vazios");
else
{
if (conta <= 1)
{
try {
String sSQL = "SELECT * FROM usuarios WHERE login like '"
+ tfLogin.getText() + "' AND senha like '" + tfSenha.getPassword()+
"' AND (nivel='adm' OR nivel='comum')";
banco_usuarios.oExecuta(sSQL);
if(banco_usuarios.oExecuta().first())
{
JOptionPane.showMessageDialog(null, "Olá, Bom Trabalho");
new sisvenda.Principal().show();
dispose();
}
else
{
conta++;
if(conta == 1)
JOptionPane.showMessageDialog(null, "Login ou Senha não conferem; Você só tem mais uma chance ");
else
{
JOptionPane.showMessageDialog(null, "Usuário inabilitado para o Sistema de Vendas ");
}
dispose();
}
}catch(Exception e){
e.printStackTrace();
}
}
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Login().setVisible(true);
}
});E quando executo esta tela gera o erro:
init:
deps-jar:
compile:
run:
Conexão efetuada com sucesso!!
Conexão efetuada com sucesso!!
java.lang.NullPointerException
at sisvenda.Login.btAcessarActionPerformed(Login.java:154)
at sisvenda.Login.access$000(Login.java:20)
at sisvenda.Login$1.actionPerformed(Login.java:69)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$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:6263)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6028)
at java.awt.Container.processEvent(Container.java:2041)
at java.awt.Component.dispatchEventImpl(Component.java:4630)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4460)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
at java.awt.Container.dispatchEventImpl(Container.java:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4460)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
EXECUTADO COM SUCESSO (tempo total: 14 segundos)
Por favor me ajudem…l
Desde ja agradeco.