PagingAndSortingRepository - custom pageable response structure

Question

Is there a way to simplify the structure returned from this controller:

@GetMapping
public Iterable getAll(@PathParam("page") int page)          


        

Answer 1

Another way is to create a custom page class as you want and create from your data and return

@Data
public class CustomPage<T> {
  List<T> content;
  CustomPageable pageable;

  public CustomPage(Page<T> page) {
    this.content = page.getContent();
    this.pageable = new CustomPageable(page.getPageable().getPageNumber(),
        page.getPageable().getPageSize(), page.getTotalElements());
  }

  @Data
  class CustomPageable {
    int pageNumber;
    int pageSize;
    long totalElements;

    public CustomPageable(int pageNumber, int pageSize, long totalElements) {

      this.pageNumber = pageNumber;
      this.pageSize = pageSize;
      this.totalElements = totalElements;
    }
  }
}

And use like this

@GetMapping
public CustomPage<Task> getAll(@PathParam("page") int page) {
    Pageable pageable = PageRequest.of(page, 3);
    return new CustomPage<Task>(taskRepository.findAll(pageable));
}

Note: Here @Data of Lombok used for setter getter etc.

Answer 2

• It looks like you have to create custom JsonSerializer with @JsonComponent annotation.

• I will copy the code for reference but you can see it here. PageImpl JSON serialization

    @JsonComponent
    public class PageImplJacksonSerializer extends JsonSerializer<PageImpl<?>> {

    @Override
    public void serialize(PageImpl page, 
                          JsonGenerator jsonGenerator, 
                          SerializerProvider serializerProvider) 
                          throws IOException {

        jsonGenerator.writeStartObject();
        jsonGenerator.writeObjectField("content", page.getContent());
        jsonGenerator.writeBooleanField("first", page.isFirst());
        jsonGenerator.writeBooleanField("last", page.isLast());
        jsonGenerator.writeNumberField("totalPages", page.getTotalPages());
        jsonGenerator.writeNumberField("totalElements", page.getTotalElements());
        jsonGenerator.writeNumberField("numberOfElements", 
                                       page.getNumberOfElements());

        jsonGenerator.writeNumberField("size", page.getSize());
        jsonGenerator.writeNumberField("number", page.getNumber());
        //sort omitted 

        jsonGenerator.writeEndObject();
      }
    }