Cacher is the code snippet organizer for pro developers

• @Document: Identifies a domain object to be persisted to MongoDB.
• @Id: Demarcates an identifier.
• @Indexed(unique = true): Mark a field to be indexed using MongoDB's indexing feature.
• @TextIndexed: marks a field to be part of the text index. As there can be only one text index per collection all fields marked with {@link TextIndexed} are combined into one single index.
• @TextScore: marks the property to be considered as the on server calculated when doing full text search. Property will not be written when saving entity.
• @DBRef: creates a reference with a document saved on another collection.

@Document(collection = "users")
public class User {

    @Id
    private String id;

    @Indexed(unique = true)
    private String username;

    @TextIndexed
    private String firstname;

    @TextIndexed
    private String lastname;

    @TextScore
    private Float textScore;

    private Address homeAddress;

    @DBRef
    private EmailAddress email;
  }

• Extend CrudRepository or PagingAndSortRepository
• main functionalities:
  • <S extends T> S save(S entity)
  • Optional<T> findById(ID primaryKey)
  • Iterable<T> findAll()
  • long count()
  • void delete(T entity)
  • boolean existsById(ID primaryKey)
  • Iterable<T> findAll(Sort sort)
  • Page<T> findAll(Pageable pageable)
• Support json query

public interface UserRepository extends PagingAndSortingRepository<User, String> {

    Page<User> findAllByUsername(@Param("username") String username, Pageable page);
    Page<User> findAllByHomeAddress_City(@Param("city") String city, Pageable page);

    @Query(" {'homeAddress.country' : ?0 } ")
    Page<User> jsonQueryFindByCountry(String country, Pageable page);

    @Query(" { 'username' : ?0 } ")
    Page<User> jsonQueryFindUsernameByRegex(String regex, Pageable page);

    Optional<User> findByEmail_Id(String emailId);

}

• Extend AbstractMongoEventListener<Document>
• Override the propper method:
  • onBeforeConvert(BeforeConvertEvent<E> event)
  • onBeforeSave(BeforeSaveEvent<E> event): get entity calling event.getSource. Note: it may not have an id.
  • onAfterSave(AfterSaveEvent<E> event): get entity calling event.getSource.
  • onAfterLoad(AfterLoadEvent<E> event)
  • onAfterConvert(AfterConvertEvent<E> event)
  • onAfterDelete(AfterDeleteEvent<E> event)
  • onBeforeDelete(BeforeDeleteEvent<E> event): get id calling:

public void onAfterSave(AfterSaveEvent<T> event) {
  Document courseClassDoc = event.getSource();
  String classID = courseClassDoc.get("_id").toString();
}

• Create a @Bean with the listener on a @Configuration file

Listener

public class UserListener extends AbstractMongoEventListener<User> {

    @Autowired
    private EmailRepository emailRepository;

    @Override
    public void onAfterSave(AfterSaveEvent<User> event) {
        User user = event.getSource();
        if (user.getEmail() != null && user.getEmail().getId() != null) {
            Optional<EmailAddress> email = emailRepository.findById(user.getEmail().getId());
            if ( email.isPresent() && !email.get().equals(user.getEmail()) ) {
                EmailAddress updatedEmail = user.getEmail();
                emailRepository.save(updatedEmail);
            }
        }
        super.onAfterSave(event);
    }
}

Configuration

@Configuration
public class MongoConfig {
    @Bean
    public UserListener userListener() {
        return new UserListener();
    }
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-data-mongodb'
    testImplementation 'de.flapdoodle.embed:de.flapdoodle.embed.mongo'
}