Reactive Elasticsearch Repositories

Reactive Elasticsearch repository support builds on the core repository support explained in Repositories utilizing operations provided via Reactive Elasticsearch Operations executed by a Reactive REST Client.spring-doc.cn

Spring Data Elasticsearch reactive repository support uses Project Reactor as its reactive composition library of choice.spring-doc.cn

There are 3 main interfaces to be used:spring-doc.cn

Usage

To access domain objects stored in a Elasticsearch using a Repository, just create an interface for it. Before you can actually go on and do that you will need an entity.spring-doc.cn

Example 1. Sample Person entity
public class Person {

  @Id
  private String id;
  private String firstname;
  private String lastname;
  private Address address;

  // … getters and setters omitted
}
Please note that the id property needs to be of type String.
Example 2. Basic repository interface to persist Person entities
interface ReactivePersonRepository extends ReactiveSortingRepository<Person, String> {

  Flux<Person> findByFirstname(String firstname);                                   (1)

  Flux<Person> findByFirstname(Publisher<String> firstname);                        (2)

  Flux<Person> findByFirstnameOrderByLastname(String firstname);                    (3)

  Flux<Person> findByFirstname(String firstname, Sort sort);                        (4)

  Flux<Person> findByFirstname(String firstname, Pageable page);                    (5)

  Mono<Person> findByFirstnameAndLastname(String firstname, String lastname);       (6)

  Mono<Person> findFirstByLastname(String lastname);                                (7)

  @Query("{ \"bool\" : { \"must\" : { \"term\" : { \"lastname\" : \"?0\" } } } }")
  Flux<Person> findByLastname(String lastname);                                     (8)

  Mono<Long> countByFirstname(String firstname)                                     (9)

  Mono<Boolean> existsByFirstname(String firstname)                                 (10)

  Mono<Long> deleteByFirstname(String firstname)                                    (11)
}
1 The method shows a query for all people with the given lastname.
2 Finder method awaiting input from Publisher to bind parameter value for firstname.
3 Finder method ordering matching documents by lastname.
4 Finder method ordering matching documents by the expression defined via the Sort parameter.
5 Use Pageable to pass offset and sorting parameters to the database.
6 Finder method concating criteria using And / Or keywords.
7 Find the first matching entity.
8 The method shows a query for all people with the given lastname looked up by running the annotated @Query with given parameters.
9 Count all entities with matching firstname.
10 Check if at least one entity with matching firstname exists.
11 Delete all entities with matching firstname.

Configuration

For Java configuration, use the @EnableReactiveElasticsearchRepositories annotation. If no base package is configured, the infrastructure scans the package of the annotated configuration class.spring-doc.cn

The following listing shows how to use Java configuration for a repository:spring-doc.cn

Example 3. Java configuration for repositories
@Configuration
@EnableReactiveElasticsearchRepositories
public class Config extends AbstractReactiveElasticsearchConfiguration {

  @Override
  public ReactiveElasticsearchClient reactiveElasticsearchClient() {
    return ReactiveRestClients.create(ClientConfiguration.localhost());
  }
}

Because the repository from the previous example extends ReactiveSortingRepository, all CRUD operations are available as well as methods for sorted access to the entities. Working with the repository instance is a matter of dependency injecting it into a client, as the following example shows:spring-doc.cn

Example 4. Sorted access to Person entities
public class PersonRepositoryTests {

  @Autowired ReactivePersonRepository repository;

  @Test
  public void sortsElementsCorrectly() {

    Flux<Person> persons = repository.findAll(Sort.by(new Order(ASC, "lastname")));

    // ...
  }
}