spring-data/cassandra/reactive/README.md

Spring Data Cassandra 2.0 - Reactive examples

This project contains samples of reactive data access features with Spring Data (Cassandra).

Reactive Template API usage with ReactiveCassandraTemplate

The main reactive Template API class is ReactiveCassandraTemplate, ideally used through its interface ReactiveCassandraOperations. It defines a basic set of reactive data access operations using Project Reactor Mono and Flux reactive types.

template.insert(Flux.just(new Person("Walter", "White", 50),
				new Person("Skyler", "White", 45),
				new Person("Saul", "Goodman", 42),
				new Person("Jesse", "Pinkman", 27)));

Flux<Person> flux = template.select(select()
                                         .from("person")
                                         .where(eq("lastname", "White")), Person.class);

The test cases in ReactiveCassandraTemplateIntegrationTest show basic Template API usage. Reactive data access reads and converts individual elements while processing the stream.

Reactive Repository support

Spring Data Cassandra provides reactive repository support with Project Reactor and RxJava 1 reactive types. The reactive API supports reactive type conversion between reactive types.

public interface ReactivePersonRepository extends ReactiveCrudRepository<Person, String> {

	Flux<Person> findByLastname(String lastname);

	@Query("SELECT * FROM person WHERE firstname = ?0 and lastname  = ?1")
	Mono<Person> findByFirstnameAndLastname(String firstname, String lastname);

	// Accept parameter inside a reactive type for deferred execution
	Flux<Person> findByLastname(Mono<String> lastname);

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

public interface RxJava1PersonRepository extends RxJava1CrudRepository<Person, String> {

	Observable<Person> findByLastname(String lastname);

	@Query("SELECT * FROM person WHERE firstname = ?0 and lastname  = ?1")
	Single<Person> findByFirstnameAndLastname(String firstname, String lastname);

	// Accept parameter inside a reactive type for deferred execution
	Observable<Person> findByLastname(Single<String> lastname);

	Single<Person> findByFirstnameAndLastname(Single<String> firstname, String lastname);
}