Spring Spring Data Page with Gson

Hello,

After changing from jackson: spring.http.converters.preferred-json-mapper=jackson to gson: spring.http.converters.preferred-json-mapper=gson

The endpoint below stopped working and started to return {}

@GetMapping
@ApiPageable
public Page<Foobar> getFoobaz() {
    return service.getFoobaz();
}

The endpoint only works if I add the annotation below:

@Configuration
@EnableWebMvc /* <-- Annotation added */
public class WebMvcConfig implements WebMvcConfigurer {

There is another issue related with this behavior: https://github.com/spring-projects/spring-framework/issues/24234

And a StackOverflow question: https://stackoverflow.com/questions/51387999/spring-data-jpa-page-and-json-with-gson

Expected behavior: returning paginated objects, same as Jackson does.

Versions used:

spring-boot:2.2.0.RELEASE
spring-webmvc:5.2.0.RELEASE

Comment From: dan1els

I think the problem is that gson expects class with default ctor, but getting Page interface. That's the error I get Unable to invoke no-args constructor for org.springframework.data.domain.Page<UserSearchData>. Registering an InstanceCreator with Gson for this type may fix this problem

Comment From: snicoll

The above is related to Spring Boot and Spring Data. Neither are handled here so if you're still affected, I'd start by reporting an issue to the Spring Data REST project.