Spring MVC validation: Only one field is required

Question

I am creating a new endpoint in this API, which accepts a request containing either a username or a 5 or 9-digit phone number. I need to add validations to validate the request to contain either a username OR phone number; if both are provided then return a validation error. Here is the current code I have.

    @GetMapping("/users")
    @Operation(summary = "API to return users based on username or phone number")
    public ResponseEntity<List<UserResponseObject>> usersByNameOrNumber(
            @Valid @RequestParam(name = "phone-number", required = false) @Pattern(regexp = "^(\\d{5}|\\d{9})$") String userPhoneNumber,
            @Valid @PathVariable(name = "user-name", required = false) @Pattern(regexp = "^[a-zA-Z ]*$") String userName) {

            try {
                    ...
            } catch (Exception e) {
                    ...
            }
    }

How can I modify this block to meet the requirements? Currently, both fields are tagged as not required and there is no validation in place. I'd like it require ONLY one of these fields to be not null.

Answer 1

Try use optional, i dont know how solution you need.

@GetMapping("/users")
                @Operation(summary = "API to return users based on username or phone number")
                public ResponseEntity<List<UserResponseObject>> usersByNameOrNumber(
                        @Valid @RequestParam(value = "phoneNumber", required = false) @Pattern(regexp = "^(\\d{5}|\\d{9})$") Optional<String> phoneNumber,
                        @Valid @RequestParam(value = "userName", required = false) @Pattern(regexp = "^[a-zA-Z ]*$") Optional<String> userName) {
            
                        try {
                                        if(phoneNumber.isPresent()){} 
                                        if(userName.isPresent()){} 
                        } catch (Exception e) {
                                
                        }
                }

But i'm not sure the @Pattern and Optional will be work good, but probably yes. Maybe is help, if i good understend your problem.