Return IDs in JSON response from Spring Data REST

Question

I've got an entity

@Entity
@Table(name = "books")
public class Book {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String name;

    @Column(name = "id", unique = true, nullable = false)
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    @Column(name = "name")
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

I initialize it like this

@PostConstruct
public void init() {
    List<String> newFiles = this.listFiles();
    newFiles.forEach(filename -> {
        Book book = new Book();
        book.setName(filename);

        dbRepository.save(book);
    });
}

If I set the result of save to an instance of Book, I can get the id and it is not null—so id is created fine.

I defined a repository

@RepositoryRestResource
public interface IBooksRepository extends CrudRepository<Book, Long> {
}

which I'd like to use to get and set data into the books table in the database.

When I try to access my repository rest using curl localhost:8080/books, I get this response

{
   "_embedded":{
      "books":[
         {
            "name":"simple-file.txt",
            "_links":{
               "self":{
                  "href":"http://localhost:8080/books/1"
               },
               "book":{
                  "href":"http://localhost:8080/books/1"
               }
            }
         }
      ]
   },
   "_links":{
      "self":{
         "href":"http://localhost:8080/books"
      },
      "profile":{
         "href":"http://localhost:8080/profile/books"
      }
   }
}

The books element returns name only. How can I make it return id too, on the same level as name?

Possible duplicate of [Spring boot @ResponseBody doesn't serialize entity id](https://stackoverflow.com/questions/24839760/spring-boot-responsebody-doesnt-serialize-entity-id) — lcnicolau, Mar 10 '19 at 00:06

Ralf Stuckert · Accepted Answer · 2017-05-18T16:01:33.143

23

Spring Data Rest hides the ID by default, in order to have it in the JSON you have to manually configure that for your entity. Depending on your spring version you can either provide your own configuration (old):

@Configuration
public class ExposeEntityIdRestConfiguration extends RepositoryRestMvcConfiguration {

    @Override
    protected void configureRepositoryRestConfiguration(RepositoryRestConfiguration config) {
        config.exposeIdsFor(Book.class);
    }
}

...or register a RepositoryRestConfigurer (current):

@Component
public class ExposeEntityIdRestMvcConfiguration extends RepositoryRestConfigurerAdapter {

  @Override
  public void configureRepositoryRestConfiguration(RepositoryRestConfiguration config) {
    config.exposeIdsFor(Book.class);
  }
}

See the Spring Data Rest documentation for more details.

edited May 18 '17 at 16:01

answered May 18 '17 at 13:56

Ralf Stuckert

1,980
12
16

Hm, there is no method `configureRepositoryRestConfiguration` in `RepositoryRestMvcConfiguration` – lapots May 18 '17 at 14:19
Which version of spring data rest are you using? – Ralf Stuckert May 18 '17 at 16:14
Do you know the reason why it is turned off by default? Looks like backbone.js requires to have the id propagated to fully function e.g. collection.get(id) – phi Jan 07 '18 at 12:56
Why did you use `@Configuration` first and `@Component` in the other one? – Villat Oct 30 '18 at 14:25
3

`RepositoryRestConfigurerAdapter` is now deprecated, you have to implement `RepositoryRestConfigurer` directly. – Yann39 May 22 '19 at 15:15
I saw a answer worked for me https://stackoverflow.com/a/61279863/2602114 – duyetpt Nov 21 '20 at 13:37

Domenico · Answer 2 · 2021-02-28T10:55:10.560

The accepted answer overrides a deprecated method. Here's the updated version:

@Component
public class RestConfig implements RepositoryRestConfigurer {

    @Override
    public void configureRepositoryRestConfiguration(RepositoryRestConfiguration config, CorsRegistry cors) {
        config.exposeIdsFor(Book.class);
    }
}

An alternative approach is to implement RepositoryRestConfigurer in your @SpringBootApplication annotated class:

@SpringBootApplication
public class MyApplication implements RepositoryRestConfigurer {

    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }

    @Override
    public void configureRepositoryRestConfiguration(RepositoryRestConfiguration config, CorsRegistry cors) {
        config.exposeIdsFor(Book.class);
    }

}

Houssam Assila · Answer 3 · 2020-04-17T20:20:32.760

3

@Component
public class RestConfig implements RepositoryRestConfigurer {

    @Override
      public void configureRepositoryRestConfiguration(RepositoryRestConfiguration config) {
        config.exposeIdsFor(Book.class);
        //config.exposeIdsFor(Library.class);
      }

}

edited Apr 17 '20 at 20:20

answered Apr 17 '20 at 20:09

Houssam Assila

31
3

2

Thanks for contributing! You might want to add a description to your answer with references to make it clearer. See https://stackoverflow.com/help/how-to-answer for guidelines. – Jean Marois Apr 18 '20 at 17:03

score 1 · Answer 4 · answered Dec 17 '19 at 07:17

There is now a static method RepositoryRestConfigurer.withConfig that does the same thing as above. See javadoc:

Convenience method to easily create simple {@link RepositoryRestConfigurer} instances that solely want to tweak the {@link RepositoryRestConfiguration}.

I found the usage in one of their integration tests

So the following approach would be more up to date as of now:

@Bean
public RepositoryRestConfigurer repositoryRestConfigurer()
{
    return RepositoryRestConfigurer.withConfig(config -> {
        config.exposeIdsFor(Book.class);
    });
}

score 1 · Answer 5 · answered Jan 06 '22 at 09:17

This is a solution which works for all entities

    @Autowired
    private EntityManager entityManager;
    
    @Bean
    public RepositoryRestConfigurer repositoryRestConfigurer() {
        return RepositoryRestConfigurer.withConfig(config -> config.exposeIdsFor(entityManager.getMetamodel().getEntities().stream().map(Type::getJavaType).toArray(Class[]::new)));
    }

score -1 · Answer 6 · answered Aug 14 '20 at 11:39

-1

This is a good way to go.

@Projection(name = "customBook", types = { Book.class }) 
public interface CustomBook {
 
    @Value("#{target.id}")
    long getId(); 
    
}

credit: https://www.baeldung.com/spring-data-rest-projections-excerpts

answered Aug 14 '20 at 11:39

Harsha Surampudi

1
1

Return IDs in JSON response from Spring Data REST

6 Answers6