Spring REST-ful uri with optional querystring

Question

The normal uri which triggers the default controller to get all cars is just "/cars"

I want to be able to search for cars aswell with an uri, for example: "/cars?model=xyz" which would return a list of matching cars. All the request parameters should be optional.

The problem is that even with the querystring the default controller triggers anyway and I always get "all cars: ..."

Is there a way to do this with Spring without a separate search uri (like "/cars/search?..")?

code:

@Controller
@RequestMapping("/cars")
public class CarController {
@Autowired
private CarDao carDao;

@RequestMapping(method = RequestMethod.GET, value = "?")
public final @ResponseBody String find(
        @RequestParam(value = "reg", required = false) String reg,
        @RequestParam(value = "model", required = false) String model
        )
{
    Car searchForCar = new Car();
    searchForCar.setModel(model);
    searchForCar.setReg(reg);
    return "found: " + carDao.findCar(searchForCar).toString();
}

@RequestMapping(method = RequestMethod.GET)
public final @ResponseBody String getAll() {
    return "all cars: " + carDao.getAllCars().toString();
} 
}

Solution 1

Try a variation of this:

    @Controller
    @RequestMapping("/cars")
    public clas CarController
    {
        @RequestMapping(method = RequestMethod.get)
        public final @ResponseBody String carsHandler(
            final WebRequest webRequest)
        {
            String parameter = webRequest.getParameter("blammy");

            if (parameter == null)
            {
                return getAll();
            }
            else
            {
                return findCar(webRequest);
            }
        }
    }

Solution 2

You can use

@RequestMapping(method = RequestMethod.GET, params = {/* string array of params required */})
public final @ResponseBody String find(@RequestParam(value = "reg") String reg, @RequestParam(value = "model") String model)
    // logic
}

ie, the @RequestMapping annotation has a property called params. If all of the parameters that you specify are contained in your request (and all other RequestMapping requirements match), then that method will be called.

Comments

[ach]

I prefer using @RequestParam-annotated parameters with required=false for this type of thing.

[user2170710]

This one seems more elegant since I don't want to have a separate method for each variation of parameters.

[emkays]

Thanks it also resolved my problem by using combination of params = {/* mandatory params */} as well as @RequestParam(value = "data", required = false, defaultValue="")