Can I use a custom parser for QueryParams?

Question

Context :

I am using Jakarta with RestEasy. I have a simple endpoint such as this one :

@GET
@Path("expectsLong")
@Produces(MediaType.TEXT_PLAIN)
public Response expectsLong(
    @QueryParam("searchValue") final Long searchValue)
{
    return ok(searchValue);
}

I am focused on applying some validation with annotations only (I'm not following the ParamConverter approach). For example :

@NotNull @Min(1) @Max(10) @QueryParam("searchValue") final Long searchValue)

By design, all of those annotations come into effect only after the initial step, which is the parsing from String to Long.

1. Step 1 : PARSING "666"  ->  666
2. Step 2 : @NotNull    ->  Is 666 null? -> no -> valid
3. Step 3 : @Min(1) -> Is 666 >= 1? -> yes -> valid
4. Step 4 : @Max(10) -> Is 666 <= 10? -> yes -> valid

(Side note: If you try to use an annotation that has nothing to do with the expected parameter's type (for example: If you tried to use @Pattern on searchValue, which is a Long) then you would get the infamous error HV000030: No validator could be found for constraint)

Problem :

The parsing step is a bit of an alien in that flow:

• Each annotation, if not satisfied, will generate an HTTP 400 with a meaningful message.
• But the parsing step will fail loudly, and nothing else. It will then get caught by RestEasy which will provide minimum service and return an HTTP 500 or HTTP 404, which is not what I want. I would like to be more efficient in catching the parsing failures, and throw a clearer exception. I want to be able to tell the caller "This String couldn't be parsed simply because it does not represent a number".

My approach :

It seems to me that I need to customize the very first step, the parsing step.

Question :

is it possible to provide a custom parser to RestEasy?