Javaslang Plugin for Microserver

micro-javaslang example apps

This plugin

1. Configures Jackson for Javaslang serialisation / deserialisation, so Javaslang types can be used as input and output to jax-rs Resources
2. Add cyclops-javaslang to your project which enables conversion between JDK / Javaslang / Guava / Jool / simple-react types and adds features such as for-comprehensions to Javaslang.
3. Integrates with micro-client, Rest clients (RestClient, AsyncRestClient and NIORestClient) automatically pick up Javaslang mappings
4. Adds some reactive programming support for Javaslang Streams namely a. JavaslangReactive mixin allows creating Javaslang reactive-streams Publishers and Subsribers simple b. JavaslangPipes and JavaslangReactive provide integration with simple-react c. Ability to push data into a Javaslang Stream across threads via JavaslangPipes

To use

Simply add this plugin to the classpath - do remember to also add a Server and jax-rs provider (adding micro-grizzly-with-jersey to your classpath too - is a good bet!)

Maven

 <dependency>
    <groupId>com.aol.microservices</groupId>  
    <artifactId>micro-javaslang</artifactId>
    <version>x.yz</version>
 </dependency>

Gradle

compile 'com.aol.microservices:micro-javaslang:x.yz'

Examples

JavaslangPipes

	
   Queue queue = QueueFactories.boundedNonBlockingQueue(1000); //set up an Agrona backed wait-free queue
   queue.add("world"); //add some data to the queue
   JavaslangPipes.register("myQueue",queue); //register the queue
   
   //on a separate thread process data streaming from the queue
   JavaslangPipes.stream("myQueue")
   			  .map(this:process)
   			  .forEach(this:save);
   

Simple App with Javaslang Lists and Sets

@Microserver
@Path("/javaslang")
@Rest
public class JavaslangApp {


   public static void main(String[] args){
   	 new MicroserverApp(() -> "javaslang-app").start();

   }

   
   @GET
   @Produces("application/json")
   @Path("/ping")
   public ImmutableJavaslangEntity ping() {
   	return ImmutableJavaslangEntity.builder().value("value")
   			.list(List.ofAll("hello", "world"))
   			.mapOfSets(HashMap.<String,Set>empty().put("key1",HashSet.ofAll(Arrays.asList(1, 2, 3))))
   			.build();
   }
   
   
   @XmlAccessorType(XmlAccessType.FIELD)
   @XmlType(name = "")
   @XmlRootElement(name = "immutable")
   @Getter
   @AllArgsConstructor
   @Builder
   public static class ImmutableJavaslangEntity {

   	private final String value;
   	private final List<String> list;
   	private final Map<String,Set> mapOfSets;
   	
   	
   	public ImmutableJavaslangEntity() {
   		this(null,null,null);
   	}
   	
   }

}    

Running the app and browsing to http://localhost:8080/javaslang-app/javaslang/ping

{
   "value": "value",
   "list": [
       "hello",
       "world"
   ],
   "mapOfSets": {
       "key1": [
           1,
           2,
           3
       ]
   }
}    

for-comprehension example

Javaslang List and JDK8 CompletableFuture

public void cfList(){
   	
   	CompletableFuture<String> future = CompletableFuture.supplyAsync(this::loadData);
   	CompletableFuture<List<String>> results1 = Do.add(future)
									    .add(List.of("first","second"))
										.yield( loadedData -> localData-> loadedData + ":" + localData )
										.unwrap();
   	
   	System.out.println(results1.join());
   	
   }
   private String loadData(){
   	return "loaded";
   }

reactive-streams publisher example

public class ReactiveStreamsPublisherTest implements JavaslangReactive {

   @Test
   public void publish(){
   	
   	Stream<Integer> javaslangStream = this.publish(LazyFutureStream.of(1,2,3));
   	
   	assertThat(javaslangStream.toList(),equalTo(List.ofAll(1,2,3)));
   }
}

reactive-streams subscriber example

 public class ReactiveStreamsSubscriberTest implements JavaslangReactive {

	
	@Test
	public void subscribe(){
		Stream<Integer> stream = Stream.ofAll(1,2,3);
		CyclopsSubscriber<Integer> sub = SequenceM.subscriber();
		this.subsribe(stream, sub);
		
		assertThat(sub.sequenceM().toList(),equalTo(Arrays.asList(1,2,3)));
	}
}

reactive-streams subscriber example on a separate thread

public class ReactiveStreamsAsyncSubscriberTest implements JavaslangReactive {


   
   @Test
   public void subscribeAsync(){
   	Stream<Integer> stream = Stream.ofAll(1,2,3);
   	CyclopsSubscriber<Integer> sub = SequenceM.subscriber();
   	this.subsribe(stream, sub,Executors.newFixedThreadPool(1));
   	
   	assertThat(sub.sequenceM().toList(),equalTo(Arrays.asList(1,2,3)));
   }
}