Controller where custom annotation is applied on Request Parameter

TestController.java

@RestController
@RequestMapping("/api/opportunity")
@Validated
public class OpportunityController {
    @GetMapping("/vendors/list")
    public String getVendorpage(@RequestParam(required = false) String term,
            @RequestParam(required = false) Integer page, @RequestParam(required = false) Integer size,
            @ValuesAllowed(propName = "orderBy", values = { "OpportunityCount", "OpportunityPublishedCount", "ApplicationCount",
                    "ApplicationsApprovedCount" }) @RequestParam(required = false) String orderBy, @RequestParam(required = false) String sortDir) {
        return "success";
    }