public ArrayList<Empleado> listarEmpleado() {
   ArrayList<Empleado> emple = new ArrayList<Empleado>();
   try {
     cn = Conexion.realizarConexion();
     st = cn.createStatement();
     String sql = "select * from empleado";
     rs = st.executeQuery(sql);
     while (rs.next()) {
       emple.add(
           new Empleado(
               rs.getString(1),
               rs.getString(2),
               rs.getString(3),
               rs.getString(4),
               rs.getString(5),
               rs.getString(6),
               rs.getString(7),
               rs.getString(8)));
     }
   } catch (ClassNotFoundException ex) {
     showMessageDialog(null, ex.getMessage(), "Excepción", 0);
   } catch (SQLException ex) {
     showMessageDialog(null, ex.getMessage(), "Excepción", 0);
   } finally {
     try {
       rs.close();
       st.close();
       cn.close();
     } catch (Exception ex) {
       showMessageDialog(null, ex.getMessage(), "Excepción", 0);
     }
   }
   return emple;
 }
 public String buscarEmpleado(String codigo) {
   try {
     cn = Conexion.realizarConexion();
     st = cn.createStatement();
     String sql =
         "select chr_emplcodigo from empleado " + " where chr_emplcodigo = '" + codigo + "'";
     rs = st.executeQuery(sql);
     while (rs.next()) {
       return rs.getString("chr_emplcodigo");
     }
   } catch (ClassNotFoundException ex) {
     showMessageDialog(null, ex.getMessage(), "Excepción", 0);
   } catch (SQLException ex) {
     showMessageDialog(null, ex.getMessage(), "Excepción", 0);
   } finally {
     try {
       rs.close();
       st.close();
       cn.close();
     } catch (Exception ex) {
       showMessageDialog(null, ex.getMessage(), "Excepción", 0);
     }
   }
   return null;
 }