I try to make my own annotation in Java for my exercise which say know if a string is a number in parameter but i don’t understand why it don’t run.

that is my interface

@Constraint(validatedBy = TestIfNumberValidator.class)
@Target({ElementType.PARAMETER,ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)

@Documented
public @interface TestIfNumber {

    String message() default "Not a number";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

}

,that is my Validator

public class TestIfNumberValidator implements ConstraintValidator<TestIfNumber, String> {
    @Override
    public boolean isValid(String value, ConstraintValidatorContext validatorContext) {
        return value != null && value.matches("\d+");
    }
}

and that where i put my annotation

@RestController
public class CalculatorService {

    @GetMapping(value = "/hello/add/{Nbr1}/{Nbr2}")
    public String addition(  @PathVariable @TestIfNumber String Nbr1, @PathVariable Integer Nbr2){
        return "Le resultat de l'addition est"
    }

I’ve tried to display an error message when i write a string in my url parameter, but nothing happens