Meetup Micronaut #meetup #micronaut

00_README.md

Slides usados disponíves no google docs e slides.com

Outros Links

• Documentação do Micronaut

01_sample_gradle.sh

take sample
mkdir -p src/main/java
touch src/main/java/Main.java
touch build.gradle

02_Main.java

public class Main {
    public static void main(String [] args){
        System.out.println("Hello");
    }
}

03_build.gradle

apply plugin: "java"
apply plugin: "application"

mainClassName = "Main"

jar {
    manifest {
        attributes("Main-Class": mainClassName)
    }
}

04_create_mn_groovy_project.sh

mn create-app sample-mn --features groovy

05_BasicSpock.groovy

package sample.mn

import spock.lang.Specification
import spock.lang.Unroll

// http://spockframework.org
class BasicSpock extends Specification {
    def "nice features"(){
        given:
            def list = [1,2]
        when:
            list.add(3)
        then:
            // https://mrhaki.blogspot.com/2013/08/spocklight-using-old-method.html
            list.size() == old(list.size()) + 1
    }

    // http://spockframework.org/spock/docs/1.3/data_driven_testing.html
    @Unroll
    def "#x + #y = #z"(){
        when:
            def result = x + y
        then:
            z == result
        where:
            x | y | z
            1 | 1 | 2
            1 | 2 | 3
            1 | 3 | 4
    }
}

06_SampleController.groovy

package sample.mn

import io.micronaut.http.annotation.Controller
import io.micronaut.http.annotation.Get

// https://guides.micronaut.io/micronaut-http-client-groovy/guide/index.html
@Controller("/hello")
class SampleController {
    @Get
    String sayHello(){
        "Hello world"
    }
}

07_PokemonClient.groovy

package sample.mn

import io.micronaut.http.annotation.Get
import io.micronaut.http.client.annotation.Client
import io.micronaut.retry.annotation.CircuitBreaker
import io.micronaut.retry.annotation.Retryable
import io.reactivex.Single

// https://guides.micronaut.io/micronaut-http-client-groovy/guide/index.html
//@CircuitBreaker
@Client("https://pokeapi.co/api/v2")
interface PokemonClient {

    @Get("/pokemon/{name}")
    Map getPokemon(String name)
}

08_PokemonClientSpec.groovy

package sample.mn

import io.micronaut.context.ApplicationContext
import io.micronaut.runtime.server.EmbeddedServer
import io.micronaut.test.annotation.MicronautTest
import spock.lang.AutoCleanup
import spock.lang.Shared;
import spock.lang.Specification

import javax.inject.Inject;

@MicronautTest
class PokemonClientSpec extends Specification {
    @Inject
    private PokemonClient client

    def "get pikachu"(){
        when:
            def response = client.getPokemon("pikachu")
            println response
        then:
            response.name == "pikachu"
    }
}

09_Kafka.groovy

package sample.mn

import io.micronaut.configuration.kafka.annotation.KafkaClient
import io.micronaut.configuration.kafka.annotation.KafkaKey
import io.micronaut.configuration.kafka.annotation.KafkaListener
import io.micronaut.configuration.kafka.annotation.OffsetReset
import io.micronaut.configuration.kafka.annotation.Topic

import javax.inject.Inject

// https://micronaut-projects.github.io/micronaut-kafka/latest/guide/
@KafkaClient
interface ProductClient {
    @Topic("my-products")
    void sendProduct(@KafkaKey String brand, String name)
}

class KafkaService{
    @Inject
    private ProductClient client

    void send(){
        client.sendProduct("Nike", "Blue Trainers")
    }
}

@KafkaListener(offsetReset = OffsetReset.EARLIEST)
class ProductListener {
    @Topic("my-products")
    void receive(@KafkaKey String brand, String name) {
        println "Got Product - ${name} by ${brand}"
    }
}

10_micronaut_graal.sh

# https://guides.micronaut.io/micronaut-creating-first-graal-app/guide/index.html

mn create-app sample-graal --features=graal-native-image
./gradlew assemble
./docker-build.sh
docker run -p 8080:8080 sample-graal

# 03:42:29.075 [main] INFO  io.micronaut.runtime.Micronaut - Startup completed in 110ms. Server Running: http://57ee6389bd17:8080