The newly introduced WebMvcConfigurer.configureMessageConverters(HttpMessageConverters.Builder) hook should allow ordering message converters to contribute converters that are used before core (built-in) converters. This was previously possible through the List-based variant configureMessageConverters(List<HttpMessageConverter<?>>) by adding converters using add(index, …).
A use-case is Spring Data's ProjectingJackson2HttpMessageConverter that is able to create JSON projections using annotated interfaces but is not suitable to write payloads to JSON, hence replacing a potentially existing MappingJackson2HttpMessageConverter/JacksonJsonHttpMessageConverter is not an option.
Comment From: sdeleuze
I guess @bclozel will have a look once back from PTO.