@QueryMap does not work with POJOs when used after @Param

This kind of code (from https://github.com/OpenFeign/feign/pull/335/files#diff-13815c678552a275075ab18b17c67784R616):

@RequestLine("GET /?name={name}")
void queryMapWithQueryParams(@Param("name") String name, @QueryMap Map<String, Object> queryMap);

Does not work when @QueryMap is used on a POJO.

In my case, I was trying to use Spring's Pageable like so:

@RequestLine("GET /things?x={x}&y={y}&z={z}")
CustomPageImpl<ThingDto> getElements(
    @Param("x") ZonedDateTime x,
    @Param("y") String y,
    @Param("z") String z,
    @QueryMap Pageable pageable);

By the way... Is there any simpler way to declare query parameters without having to refer four times to their names?

Start by reproducing the supplied @QueryMap POJO and Spring Pageable cases after an @Param, then read the RequestLine, @Param, and @QueryMap handling. Done means POJO query properties work regardless of parameter order, with regression coverage for the shown signatures; the question about simpler declarations is separate.