package dao;

import classes.Login;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.swing.JOptionPane;

public class Acesso {

public boolean acesso;

public void Acesso(String login, String senha) {

    Login lg = new Login();

    try {

        Connection con = Conecta.getconexao();
        Statement stmt = con.createStatement();
        String query = "select login, senha from tbl_login where login='" + login + "'and senha='" + senha + "'";

        ResultSet rs = stmt.executeQuery(query);

        if (rs.next()) {
            lg.setUsuario(rs.getString("login"));
            lg.setSenha(rs.getString("senha"));
            JOptionPane.showMessageDialog(null, "Usuário Logado com Sucesso!!!");
            acesso = true;
        } else {
            System.out.println(rs.next());
            System.out.println(query);
            JOptionPane.showMessageDialog(null, "Usuário Inválido!!!");
            acesso = false;

        }
    } catch (Exception e) {
        JOptionPane.showMessageDialog(null, "ENTROU NO CATCH DO ACESSO()");
    }
}
}

package dao;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class Conecta{
public static Connection getconexao(){
Connection con = null;

try{
    String serverName = "localhost";
    String mydatabase = "db";
    String username = "system";
    String password = "123456";
    String driverName = "oracle.jdbc.driver.OracleDriver";
    Class.forName(driverName);

    String url = "jdbc:oracle:thin:@localhost:1521:XE";
    con = DriverManager.getConnection(url, username, password);

}
catch (ClassNotFoundException e){
    System.out.println("Driver não encontrado " + e.toString());
}
catch(SQLException e){
    System.out.println("Erro ao conectar o Banco de Dados " + e.toString());
}

    return con;
}

}

private void btnAcessarActionPerformed(java.awt.event.ActionEvent evt) {

    Acesso cl = new Acesso();
    cl.Acesso(txtLogin.getText(), txtSenha.getText());

    if (cl.acesso = true) {
        TelaInicial tl = new TelaInicial();
        tl.setExtendedState(new TelaInicial().MAXIMIZED_BOTH);
        tl.setVisible(true);

    } else {
            txtLogin.setText("");
            txtSenha.setText("");
            txtLogin.requestFocus();
    }
}