[resteasy-reactive] Custom query param key extractor

[sliw39]

Hi all,

I'm trying to implement a RESTeasy endpoint that matches the HL7 FHIR specification for "search" (https://www.hl7.org/fhir/search.html#modifiers).

I'm struggling with the "modifier" aspect of the implementation. For example, this request
GET [base]/Patient?family:contains=son

will fall into the following Java code:

@GET
public List<Patient> searchPatient(@QueryParam("family:contains") String familly) {
   // code
} 

But I don't want to create a method for every parameters and every modifiers.

Is there a way to have an implementation like this ?

@GET
public List<Patient> searchPatient(@CustomQueryParam("family") StringParam family) {
   String modifier = family.modifier;
   String value = family.value;
} 

Thanks for your help !

[quarkus-bot[bot]]

/cc @FroMage (resteasy-reactive), @geoand (resteasy-reactive), @stuartwdouglas (resteasy-reactive)

[geoand]

Have you had a look at the ParamConverter API?

[sliw39]

Yes I did, but as I understood, it works on the value part of the query param, not on the key.
Here in my example, the syntax is key:modifier=value,

[geoand]

Ah, I see.

I don't have any good solution for you at this point.

[luca-bassoricci]

1. Manual parsing of query params or
2. a custom paramconverter which (de)serialize an object holding all modifiers as a single query param?

[sliw39]

1. This is actualy a solution I consider, but I will not be able to generate my interfaces with openAPI anymore.
2. That could be also a better solution, but I must follow the FHIR spec, so my delimiter must be a ":", not a "."

Digging into the code, I ran over QueryParamExtractor which is used here

Maybe there is a way to overload or configure the delimiter ?

[luca-bassoricci]

1. OpenAPI can be easily manual described; of course can be a tedious task
2. Sorry, I was incorrect and I edited my post.

All above points requires you have to manual describe OpenAPI so manual parsing seems to be the better solution and give you a readable query string.

QueryParamExtractor seems to be a sort of glue code used to call the real parameter extractor using the right API detected during build phase of application; @geoand for sure can give the right explanation about what QueryParamExtractor is used for :)

[sliw39]

We found a workaround that may help someone one day :
We declared a VertX @RouteFilter(400) to rewrite the incomming url to a format understood by Resteasy.
key:modifier=value is transformed into key.modifier=value then use a QueryParamExtractor

[geoand]

Good idea!