frmLogin.java

package VISUAL;
import java.sql.*;
import DAL.ConectaBd;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;

public class frmLogin extends javax.swing.JFrame {

    Connection con = null;
    PreparedStatement pst = null;
    ResultSet rs = null;

    public frmLogin() throws ClassNotFoundException {
        initComponents();
        setLocationRelativeTo(null);
        con = ConectaBd.conectabd();
    }

    public void Logar(){

    String sql;

    // UNICA COISA QUE EU MUDEI:
    sql = "SELECT * FROM Login WHERE usuario=? AND senha=?";

    try{
        pst = con.prepareStatement(sql);
        pst.setString(1, txtUsuario.getText());
        pst.setString(2, txtSenha.getText());
        rs = pst.executeQuery();

        if(rs.next()){
            frmPrincipal frm = new frmPrincipal();
            frm.setVisible(true);
        }
        else{
            JOptionPane.showMessageDialog(null, "Usuario e Senha Incorretos ou Invalidos");
        }
    }
    catch(SQLException error){
        JOptionPane.showMessageDialog(null, error);
    }


    }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        txtUsuario = new javax.swing.JTextField();
        jButton1 = new javax.swing.JButton();
        txtSenha = new javax.swing.JPasswordField();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jLabel1.setText("Login:");

        jLabel2.setText("Senha:");

        jButton1.setText("Entrar");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(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()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addGap(100, 100, 100)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addGroup(layout.createSequentialGroup()
                                .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 34, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addGap(18, 18, 18)
                                .addComponent(txtUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, 129, javax.swing.GroupLayout.PREFERRED_SIZE))
                            .addGroup(layout.createSequentialGroup()
                                .addComponent(jLabel2)
                                .addGap(18, 18, 18)
                                .addComponent(txtSenha, javax.swing.GroupLayout.PREFERRED_SIZE, 129, javax.swing.GroupLayout.PREFERRED_SIZE))))
                    .addGroup(layout.createSequentialGroup()
                        .addGap(169, 169, 169)
                        .addComponent(jButton1)))
                .addContainerGap(119, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap(115, Short.MAX_VALUE)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 29, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(txtUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(txtSenha, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(27, 27, 27)
                .addComponent(jButton1)
                .addGap(67, 67, 67))
        );

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

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
        Logar();
    }

    public static void main(String args[]) {

        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                try{
                new frmLogin().setVisible(true);
                }
                catch(ClassNotFoundException ex){
                Logger.getLogger(frmLogin.class.getName()).log(Level.SEVERE,null, ex);
                }
            }
        });
    }

    // Variables declaration - do not modify
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JPasswordField txtSenha;
    private javax.swing.JTextField txtUsuario;
    // End of variables declaration
}