d9f77903ef
We now check whether an external Apache Cassandra instance is available at localhost:9042 and use it to run the examples. Otherwise, if no external Apache Cassandra instance is available, we start an embedded Cassandra instance.
57 lines
2.3 KiB
Markdown
57 lines
2.3 KiB
Markdown
# 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](http://projectreactor.io) `Mono` and `Flux` reactive types.
|
|
|
|
```java
|
|
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.
|
|
|
|
```java
|
|
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);
|
|
}
|
|
```
|
|
|
|
```java
|
|
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);
|
|
}
|
|
```
|