Return single database entry - regex

Question

The following snippet is able to return all the cars in my database as a JSON when I call the URL 1 and I can display them in the browser. However, when I use the URL 2, I get nothing and the browser displays the 404 error. But it is weird that the error does not show the message "Car not found". It shows "The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.".
I tested the RegexUtil class and it does return the Long as 1 when I call the URL 2 and Long equal to null when I call the URL 1.
What am I doing wrong?
1) http://localhost:8080/Cars/cars
2) http://localhost:8080/Cars/cars/1
String requestUri = request.getRequestURI();
Long id = RegexUtil.matchId(requestUri);
if (id != null) {
//this if test is never executed even when id != null
// id was informed
Car car = carService.getCar(id);
if (car != null) {
Gson gson = new GsonBuilder().setPrettyPrinting().create();
String json = gson.toJson(car);
ServletUtil.writeJSON(response, json);
} else {
response.sendError(404, "Car not found");
}
} else {
//this else executes fine
// Show car list
List<Car> cars = carService.getCars();
Gson gson = new GsonBuilder().setPrettyPrinting().create();
String json = gson.toJson(cars);
ServletUtil.writeJSON(response, json);
}

Answer 1

Issue resolved.
The servlet annotation was incorrect.
The asterisk was missing
#WebServlet(urlPatterns = { "/cars/*" },