How to resolve LazyInitializationException in Spring Data JPA?

Question

I have to classes that have a one-to-many-relation. When I try to access the lazily loaded collection I get the LazyInitializationException. I searching the web

Answer 1

For those who have not the possibility to use JPA 2.1 but want to keep the possibility to return a entity in their controller (and not a String/JsonNode/byte[]/void with write in response):

there is still the possibility to build a DTO in the transaction, that will be returned by the controller.

@RestController
@RequestMapping(value = FooController.API, produces = MediaType.APPLICATION_JSON_VALUE)
class FooController{

    static final String API = "/api/foo";

    private final FooService fooService;

    @Autowired
    FooController(FooService fooService) {
        this.fooService= fooService;
    }

    @RequestMapping(method = GET)
    @Transactional(readOnly = true)
    public FooResponseDto getFoo() {
        Foo foo = fooService.get();
        return new FooResponseDto(foo);
    }
}