Source code for the article "An Intro to Spring with Akka" (#541)

spring-all/pom.xml

@@ -45,11 +45,6 @@
             <artifactId>spring-aspects</artifactId>
         </dependency>
 
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-orm</artifactId>
-        </dependency>
-
         <!-- persistence -->
 
         <dependency>
@@ -92,6 +87,14 @@
             <scope>runtime</scope>
         </dependency>
 
+        <!-- Akka -->
+
+        <dependency>
+            <groupId>com.typesafe.akka</groupId>
+            <artifactId>akka-actor_2.11</artifactId>
+            <version>2.4.8</version>
+        </dependency>
+
         <!-- util -->
 
         <dependency>

spring-all/src/main/java/org/baeldung/akka/AppConfiguration.java

@@ -0,0 +1,26 @@
+package org.baeldung.akka;
+
+import akka.actor.ActorSystem;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+import static org.baeldung.akka.SpringExtension.SPRING_EXTENSION_PROVIDER;
+
+@Configuration
+@ComponentScan
+public class AppConfiguration {
+
+    @Autowired
+    private ApplicationContext applicationContext;
+
+    @Bean
+    public ActorSystem actorSystem() {
+        ActorSystem system = ActorSystem.create("akka-spring-demo");
+        SPRING_EXTENSION_PROVIDER.get(system).initialize(applicationContext);
+        return system;
+    }
+
+}

spring-all/src/main/java/org/baeldung/akka/GreetingActor.java

@@ -0,0 +1,43 @@
+package org.baeldung.akka;
+
+import akka.actor.UntypedActor;
+import org.springframework.context.annotation.Scope;
+import org.springframework.stereotype.Component;
+
+import static org.springframework.beans.factory.config.ConfigurableBeanFactory.SCOPE_PROTOTYPE;
+
+@Component
+@Scope(SCOPE_PROTOTYPE)
+public class GreetingActor extends UntypedActor {
+
+    private GreetingService greetingService;
+
+    public GreetingActor(GreetingService greetingService) {
+        this.greetingService = greetingService;
+    }
+
+    @Override
+    public void onReceive(Object message) throws Throwable {
+        if (message instanceof Greet) {
+            String name = ((Greet) message).getName();
+            getSender().tell(greetingService.greet(name), getSelf());
+        } else {
+            unhandled(message);
+        }
+    }
+
+    public static class Greet {
+
+        private String name;
+
+        public Greet(String name) {
+            this.name = name;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+    }
+
+}

spring-all/src/main/java/org/baeldung/akka/GreetingService.java

@@ -0,0 +1,12 @@
+package org.baeldung.akka;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class GreetingService {
+
+    public String greet(String name) {
+        return "Hello, " + name;
+    }
+
+}

spring-all/src/main/java/org/baeldung/akka/SpringActorProducer.java

@@ -0,0 +1,28 @@
+package org.baeldung.akka;
+
+import akka.actor.Actor;
+import akka.actor.IndirectActorProducer;
+import org.springframework.context.ApplicationContext;
+
+public class SpringActorProducer implements IndirectActorProducer {
+
+    private ApplicationContext applicationContext;
+
+    private String beanActorName;
+
+    public SpringActorProducer(ApplicationContext applicationContext, String beanActorName) {
+        this.applicationContext = applicationContext;
+        this.beanActorName = beanActorName;
+    }
+
+    @Override
+    public Actor produce() {
+        return (Actor) applicationContext.getBean(beanActorName);
+    }
+
+    @Override
+    public Class<? extends Actor> actorClass() {
+        return (Class<? extends Actor>) applicationContext.getType(beanActorName);
+    }
+
+}

spring-all/src/main/java/org/baeldung/akka/SpringExtension.java

@@ -0,0 +1,33 @@
+package org.baeldung.akka;
+
+import akka.actor.AbstractExtensionId;
+import akka.actor.ExtendedActorSystem;
+import akka.actor.Extension;
+import akka.actor.Props;
+import org.springframework.context.ApplicationContext;
+
+public class SpringExtension extends AbstractExtensionId<SpringExtension.SpringExt> {
+
+    public static final SpringExtension SPRING_EXTENSION_PROVIDER = new SpringExtension();
+
+    @Override
+    public SpringExt createExtension(ExtendedActorSystem system) {
+        return new SpringExt();
+    }
+
+    public static class SpringExt implements Extension {
+
+        private volatile ApplicationContext applicationContext;
+
+        public void initialize(ApplicationContext applicationContext) {
+            this.applicationContext = applicationContext;
+        }
+
+        public Props props(String actorBeanName) {
+            return Props.create(SpringActorProducer.class, applicationContext, actorBeanName);
+        }
+
+    }
+
+
+}

spring-all/src/test/java/org/baeldung/akka/SpringAkkaTest.java

@@ -0,0 +1,48 @@
+package org.baeldung.akka;
+
+import java.util.concurrent.TimeUnit;
+
+import akka.actor.ActorRef;
+import akka.actor.ActorSystem;
+import akka.util.Timeout;
+import org.baeldung.akka.GreetingActor.Greet;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.AbstractJUnit4SpringContextTests;
+import scala.concurrent.Await;
+import scala.concurrent.Future;
+import scala.concurrent.duration.FiniteDuration;
+
+import static akka.pattern.Patterns.ask;
+import static org.baeldung.akka.SpringExtension.SPRING_EXTENSION_PROVIDER;
+
+@ContextConfiguration(classes = AppConfiguration.class)
+public class SpringAkkaTest extends AbstractJUnit4SpringContextTests {
+
+    @Autowired
+    private ActorSystem system;
+
+    @Test
+    public void whenCallingGreetingActor_thenActorGreetsTheCaller() throws Exception {
+        ActorRef greeter = system.actorOf(
+                SPRING_EXTENSION_PROVIDER.get(system)
+                        .props("greetingActor"), "greeter");
+
+        FiniteDuration duration = FiniteDuration.create(1, TimeUnit.SECONDS);
+        Timeout timeout = Timeout.durationToTimeout(duration);
+
+        Future<Object> result = ask(greeter, new Greet("John"), timeout);
+
+        Assert.assertEquals("Hello, John", Await.result(result, duration));
+    }
+
+    @After
+    public void tearDown() {
+        system.shutdown();
+        system.awaitTermination();
+    }
+
+}