#215 - Add reactive examples for MongoDB, Apache Cassandra and Redis.

mongodb/reactive/README.md

@@ -0,0 +1,66 @@
+# Spring Data MongoDB 2.0 - Reactive examples
+
+This project contains samples of reactive data access features with Spring Data (MongoDB).
+
+## Prerequisites
+
+MongoDB requires the Reactive Streams driver to provide reactive data access. 
+The Reactive Streams driver maintains its own connections. Using Spring Data MongoDB Reactive support 
+together with blocking Spring Data MongoDB data access will open multiple connections to your MongoDB servers.
+
+## Reactive Template API usage with `ReactiveMongoTemplate` 
+
+The main reactive Template API class is `ReactiveMongoTemplate`, ideally used through its interface `ReactiveMongoOperations`. It defines a basic set of reactive data access operations using [Project Reactor](http://projectreactor.io) `Mono` and `Flux` reactive types.
+
+```java
+template.insertAll(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.find(Query.query(Criteria.where("lastname").is("White")), Person.class);
+```
+
+The test cases in `ReactiveMongoTemplateIntegrationTest` show basic Template API usage. 
+Reactive data access reads and converts individual elements while processing the stream.
+
+
+## Reactive Repository support
+ 
+Spring Data MongoDB 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("{ 'firstname': ?0, '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);
+	
+	@InfiniteStream // Use a tailable cursor
+	Flux<Person> findWithTailableCursorBy();
+}
+```
+
+```java
+public interface RxJava1PersonRepository extends RxJava1CrudRepository<Person, String> {
+
+	Observable<Person> findByLastname(String lastname);
+
+	@Query("{ 'firstname': ?0, '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);
+
+	@InfiniteStream // Use a tailable cursor
+	Observable<Person> findWithTailableCursorBy();
+}
+```