hstraub / akka-streams-examples

Learning Akka Streams with examples. Akka Streams Version 1.0

This project

Learning Akka Streams 1.0 with simple examples.

Examples

• InMemory: running a simple stream.
• DefineStreams: running a simple Sink.fold stream - calculate the sum of an integer stream.
• ReactiveTweets: stream filters case class objects.
• FileReader: reading file content and output the content to stdout
• EchoServer: an echo tcp server implementation in four lines :)
• SimpleServer: tcp server understands one command.
• ReplClient: tcp server understands two commands.
• SinkActorRef: connect a simple actor as sink.
• MyActorSubscriber: ActorSubscriber example
• HttpClientFlowBased: reading from urls and write the content to stdout and calculates the packet and byte count. Two implementations: onComplete and functional.
• HttpClientFlowBased2: reading from urls and write the content to stdout and calculates the packet and byte count (functional).
• HttpClientFlowBased3: reading from Elasticsearch or CouchDb and store the content into Elasticsearch. Implementation with two asynchrous streams.
• Group: Using Flow.group and groupWithin: Chunk up this stream into groups of the given size or within a time window. Todo: terminate a running stream.
• BalanceMerge: Using Balance and merge. Split the implementation in a Flows and Graphs object.
• TcpServer2: Same as EchoServer, but reusing the Flows and Graphs definitions from BalanceMerge.
• HttpLowLevelServer: using the akka http low level server API.
• HttpLowLevelServerAsync: the async implementation.
• HttpLowLevelServerAsyncFlow: running a flow on the HttpRequest data.
• HttpHighLevelServerMinimal: using the akka http high level server API and requires akka-http-xml-experimental (build.sbt).
• HttpHighLevelServerRoutes: playing with route composition.

Requirements

• Some examples needs a running Elasticsearch installation. See Elasticsearch Setup and Installation instructions

Build instructions

Requirements: java >= 1.6, sbt, optional scala-ide

git clone ...

Build and run:

sbt run

Prepare Scala-Ide:

sbt eclipse

and import project.

Documents

• Akka Streams 1.0 API documentation / Scala
• Reference documentation / Scala

Typesafe Webinars

• Reactive Streams 1.0.0 and why you should care

Worth reading

• Do's and Dont's When Deploying Akka in Production
• Reactive Kafka source code
• Akka Reactive Streams example
• Connecting dots with Akka Streams - microservice, implementing sink and source - error handling
• Comparing Akka Streams and Scalaz Streams with code examples
• Java Code Geeks - Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo