Spring boot 2

Libraries

This project uses Spring boot 2, Spring WebFlux, Reactive MongoDB, Lombok and Twitter4J.

Configuration

To get this project up and running, you need to configure the following environment variables or application properties:

• TWITTER_CONSUMER_KEY
• TWITTER_CONSUMER_SECRET
• TWITTER_ACCESS_TOKEN
• TWITTER_ACCESS_TOKEN_SECRET

These details can be generated at Twitter Application Management.

Resources

• Presentation
• Blogpost about getting started with Spring boot 2
• Blogpost containing conference talks about Spring boot 2

Snippets from presentation

Key components

// Flux<Integer> extends Publisher<Integer>
Flux.range(0, 1000)
    // Operators
    .filter(nr -> nr % 2 == 0)
    .map(nr -> nr * 3)
    // Subscriber
    .subscribe(System.out::println);

Webflux

@RestController
@RequestMapping("/api/person")
public class PersonController {
    @GetMapping
    public Flux<Person> findAll() { // Returns Flux<Person>
        return Flux.just(
        	new Person("John", "Doe"),
	        new Person("Jane", "Doe"));
    }
}

Router function

@Bean
public RouterFunction<?> routes() {
    return route(GET("/api/person"), request -> ServerResponse
        .ok()
        .body(Flux.just(
        	new Person("John", "Doe"),
        	new Person("Jane", "Doe")), Person.class));
}

Reactive repository

public interface PersonRepository extends ReactiveCrudRepository<Person, String> {
    
}

WebClient

WebClient
	// Base path
	.create("http://localhost:8080/api")
    .get()
    .uri(uriBuilder -> uriBuilder
    	.path("/person")
        .queryParam("offset", 0)
        .queryParam("limit", 10)
        .build())
    .retrieve()
    // Returns Flux<Person>
    .bodyToFlux(Person.class);