How to map Page<ObjectEntity> to Page<ObjectDTO> in spring-data-rest

Question

When I hit the database with PagingAndSortingRepository.findAll(Pageable) I get Page<ObjectEntity>. However, I want to expose DTO's to the client and not entities. I can create DTO just by injecting entity into it's constructor, but how do I map the entities in Page object to DTO's? According to spring documentation, Page provides read-only operations.

Also, Page.map is not possibility, as we don't have support for java 8. How to create the new Page with mapped objects manually?

Answer 1

You can still use the Page.map without lambda expressions:

Page<ObjectEntity> entities = objectEntityRepository.findAll(pageable); Page<ObjectDto> dtoPage = entities.map(new Converter<ObjectEntity, ObjectDto>() {     @Override     public ObjectDto convert(ObjectEntity entity) {         ObjectDto dto = new ObjectDto();         // Conversion logic          return dto;     } }); 

Answer 2

In Spring Data 2, the Page map method takes a Function instead of a Converter, but it still works basically the same as @Ali Dehghani described.

Using Function:

Page<ObjectEntity> entities = objectEntityRepository.findAll(pageable); Page<ObjectDto> dtoPage = entities.map(new Function<ObjectEntity, ObjectDto>() {     @Override     public ObjectDto apply(ObjectEntity entity) {         ObjectDto dto = new ObjectDto();         // Conversion logic          return dto;     } });