How to display data in a Textfield in javafx

Good who could help me to show data from a textfield I have this code and nothing that works for me.

Method to verify client

    public int existeCliente(String cliente) {

        // llamamos a la conexion bd
        PreparedStatement ps = null;
        ResultSet rs = null;
        Connection con = getConexionTemporal();
        // Preparamos la consulta
        String sql = "SELECT count(id_cliente) FROM cliente WHERE 
                          cli_cedula=?";
        try {
            // Traemos los datos de la bd
            ps = con.prepareStatement(sql);
            ps.setString(1, cliente);
            rs = ps.executeQuery();
            // Cargamos los resultados
            if (rs.next()) {
                return rs.getInt(1);

            }
        } catch (SQLException e) {
            e.printStackTrace();

        } finally {

            cerrarObjeto(con);
            cerrarObjeto(rs);
            cerrarObjeto(ps);

        }
        return 1;
    }

and in the controller this I have // Client search method

@FXML
void buscarCliente(ActionEvent event) {
    SqlFacturar cliente = new SqlFacturar();
    // Validamos los campos que no esten vacios
            if (txt_cedula.getText().equals("")) {
                // validamos campos
                Validaciones.checkEmptyFields(txt_cedula);
            }else{
    if (cliente.existeCliente(txt_cedula.getText())==0) {

JOptionPane.showMessageDialog (null,  "Client does not exist, you must register it!");

    }else{

        txt_nombre.setText(cli.getNombre());        
    }
}
}

Thank you very much for helping me.