resource link rel with id spring data rest

Question

Having following Entities and Repositories. I could'nt manage to put the id on my relationship. Thanks in advance for your help

Related artifacts from my build.gradle (using Spring Boot version 1.5.4.RELEASE )

compile('org.springframework.boot:spring-boot-starter-data-jpa')
compile('org.springframework.boot:spring-boot-starter-data-rest')

---

Entities

Store

@Entity
@Table(name = "store")
class Store {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    long id

    String description

    @ManyToOne(optional=false, fetch = FetchType.EAGER)
    Province province
}

Province

@Entity
@Table(name = "province")
class Province {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    long id

    @NotNull
    String name
}

---

Repositories

Store

@RepositoryRestResource(collectionResourceRel = "stores", path = "stores")
interface StoreRepository extends PagingAndSortingRepository<Store, Long> {
}

Province

@RepositoryRestResource(collectionResourceRel = "provinces", path = "provinces")
interface ProvinceRepository extends PagingAndSortingRepository<Province, Long> {
}

---

Expected Result I'm expecting this result, please note link on Province

{
 "stores": [
  {
    "id": 1,
    "description": "desc1",
    "_links": {
      "self": {
        "href": "http://localhost:8080/stores/1"
      },
      "store": {
        "href": "http://localhost:8080/stores/1"
      },
      "province": {
        "href": "http://localhost:8080/stores/1/province/1" ==> Expecting the url with provinceID since its many to one
      }
    }
  }
 ]
  //Simplified for simplicity sake
}

Actual Result Not having the Province Id in href

{
 "stores": [
  {
    "id": 1,
    "description": "desc1",
    "_links": {
      "self": {
        "href": "http://localhost:8080/stores/1"
      },
      "store": {
        "href": "http://localhost:8080/stores/1"
      },
      "province": {
        "href": "http://localhost:8080/stores/1/province" ==> //NO ID!
      }
    }
  }
 ]
  //Simplified for simplicity sake
}

---

Basically im expecting

this

"province": {
            "href": "http://localhost:8080/stores/1/province/1" ==> Expecting the url with provinceID since its many to one
          }

instead of this

  "province": {
    "href": "http://localhost:8080/stores/1/province" //NO province ID
  }

---

Edit Jun 21 at 11:54 I've changed FetchType.LAZY to EAGER on Store due to an error when trying to do

"http://localhost:8080/stores/1/province/1"

GOT

"org.springframework.http.converter.HttpMessageNotWritableException",
  "message": "Could not write JSON: No serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer

Answer 1

Finally i've found two possibles ways to solve this one with Projections and the other using ResourceProcessor . Hope this help somebody.

Projections .

@Projection(name="storeProjection", types={Store.class})
interface StoreProjection {

    long getId();
    String getDescription();
    String getPhoneNumber();
    StoreStatus getStatus();

    @Value("#{target.province.id}")
    Long getProvinceId();

    @Value("#{target.province.name}")
    String getProvinceName();
}

GET http://localhost:8080/stores?projection=storeProjection

JSON result

{
  //Store data...

    "provinceId": "1"
    "provinceName": "Prov1"

 //Links,etc data
}

---

ResourceProcessor in order to add a new link with desired info

@Configuration
class ResourcesProcessors {

    @Autowired
    EntityLinks entityLinks

    @Bean
    public ResourceProcessor<Resource<Store>> storeProcessor() {

        return new ResourceProcessor<Resource<Store>>() {
            @Override
            public Resource<Store> process(Resource<Store> resource) { //Este punto solo se agregan nuevos links

                Store store = resource.getContent()
                Link link = entityLinks.linkToSingleResource(Province.class, store.province.id);
                resource.add(link);
                return resource;
            }
        };
    }
}