BAEL-550 Axon framework

* BEEL-550 create axon module

* BEEL-550 proper naming

* BEEL-550 better example of message service

* BEEL-550 proper name of method

* BEEL-550 remove not needed comments

* BEEL-550 proper message

* BEEL-550 axon test scope test

* BEEL-550 tries to migrate to axon 3

* BEEL-550 migrate to vesrion 3 successfull

axon/pom.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>parent-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>axon</artifactId>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.axonframework</groupId>
+            <artifactId>axon-test</artifactId>
+            <version>${axon.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.axonframework</groupId>
+            <artifactId>axon-core</artifactId>
+            <version>${axon.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <axon.version>3.0.2</axon.version>
+        <junit.version>4.12</junit.version>
+    </properties>
+
+
+</project>

axon/src/main/java/com/baeldung/axon/MessagesRunner.java

@@ -0,0 +1,54 @@
+package com.baeldung.axon;
+
+import com.baeldung.axon.aggregates.MessagesAggregate;
+import com.baeldung.axon.commands.CreateMessageCommand;
+import com.baeldung.axon.commands.MarkReadMessageCommand;
+import com.baeldung.axon.eventhandlers.MessagesEventHandler;
+import org.axonframework.commandhandling.AggregateAnnotationCommandHandler;
+import org.axonframework.commandhandling.CommandBus;
+import org.axonframework.commandhandling.SimpleCommandBus;
+import org.axonframework.commandhandling.gateway.CommandGateway;
+import org.axonframework.commandhandling.gateway.DefaultCommandGateway;
+import org.axonframework.eventhandling.AnnotationEventListenerAdapter;
+import org.axonframework.eventsourcing.EventSourcingRepository;
+import org.axonframework.eventsourcing.eventstore.EmbeddedEventStore;
+import org.axonframework.eventsourcing.eventstore.EventStore;
+import org.axonframework.eventsourcing.eventstore.inmemory.InMemoryEventStorageEngine;
+
+import java.util.UUID;
+
+public class MessagesRunner {
+
+    public static void main(String[] args) {
+        CommandBus commandBus = new SimpleCommandBus();
+
+        CommandGateway commandGateway = new DefaultCommandGateway(commandBus);
+
+        EventStore eventStore = new EmbeddedEventStore(new InMemoryEventStorageEngine());
+
+        EventSourcingRepository<MessagesAggregate> repository =
+                new EventSourcingRepository<>(MessagesAggregate.class, eventStore);
+
+
+        AggregateAnnotationCommandHandler<MessagesAggregate> messagesAggregateAggregateAnnotationCommandHandler =
+                new AggregateAnnotationCommandHandler<MessagesAggregate>(MessagesAggregate.class, repository);
+        messagesAggregateAggregateAnnotationCommandHandler.subscribe(commandBus);
+
+        final AnnotationEventListenerAdapter annotationEventListenerAdapter =
+                new AnnotationEventListenerAdapter(new MessagesEventHandler());
+        eventStore.subscribe(eventMessages -> eventMessages.forEach(e -> {
+                    try {
+                        annotationEventListenerAdapter.handle(e);
+                    } catch (Exception e1) {
+                        throw new RuntimeException(e1);
+
+                    }
+                }
+
+        ));
+
+        final String itemId = UUID.randomUUID().toString();
+        commandGateway.send(new CreateMessageCommand(itemId, "Hello, how is your day? :-)"));
+        commandGateway.send(new MarkReadMessageCommand(itemId));
+    }
+}

axon/src/main/java/com/baeldung/axon/aggregates/MessagesAggregate.java

@@ -0,0 +1,36 @@
+package com.baeldung.axon.aggregates;
+
+import com.baeldung.axon.commands.CreateMessageCommand;
+import com.baeldung.axon.commands.MarkReadMessageCommand;
+import com.baeldung.axon.events.MessageCreatedEvent;
+import com.baeldung.axon.events.MessageReadEvent;
+import org.axonframework.commandhandling.CommandHandler;
+import org.axonframework.commandhandling.model.AggregateIdentifier;
+import org.axonframework.eventhandling.EventHandler;
+
+import static org.axonframework.commandhandling.model.AggregateLifecycle.apply;
+
+
+public class MessagesAggregate {
+
+    @AggregateIdentifier
+    private String id;
+
+    public MessagesAggregate() {
+    }
+
+    @CommandHandler
+    public MessagesAggregate(CreateMessageCommand command) {
+        apply(new MessageCreatedEvent(command.getId(), command.getText()));
+    }
+
+    @EventHandler
+    public void on(MessageCreatedEvent event) {
+        this.id = event.getId();
+    }
+
+    @CommandHandler
+    public void markRead(MarkReadMessageCommand command) {
+        apply(new MessageReadEvent(id));
+    }
+}

axon/src/main/java/com/baeldung/axon/commands/CreateMessageCommand.java

@@ -0,0 +1,24 @@
+package com.baeldung.axon.commands;
+
+
+import org.axonframework.commandhandling.TargetAggregateIdentifier;
+
+public class CreateMessageCommand {
+ 
+    @TargetAggregateIdentifier
+    private final String id;
+    private final String text;
+ 
+    public CreateMessageCommand(String id, String text) {
+        this.id = id;
+        this.text = text;
+    }
+ 
+    public String getId() {
+        return id;
+    }
+ 
+    public String getText() {
+        return text;
+    }
+}

axon/src/main/java/com/baeldung/axon/commands/MarkReadMessageCommand.java

@@ -0,0 +1,18 @@
+package com.baeldung.axon.commands;
+
+
+import org.axonframework.commandhandling.TargetAggregateIdentifier;
+
+public class MarkReadMessageCommand {
+ 
+    @TargetAggregateIdentifier
+    private final String id;
+ 
+    public MarkReadMessageCommand(String id) {
+        this.id = id;
+    }
+ 
+    public String getId() {
+        return id;
+    }
+}

axon/src/main/java/com/baeldung/axon/eventhandlers/MessagesEventHandler.java

@@ -0,0 +1,19 @@
+package com.baeldung.axon.eventhandlers;
+
+import com.baeldung.axon.events.MessageReadEvent;
+import com.baeldung.axon.events.MessageCreatedEvent;
+import org.axonframework.eventhandling.EventHandler;
+
+
+public class MessagesEventHandler {
+
+    @EventHandler
+    public void handle(MessageCreatedEvent event) {
+        System.out.println("Message received: " + event.getText() + " (" + event.getId() + ")");
+    }
+
+    @EventHandler
+    public void handle(MessageReadEvent event) {
+        System.out.println("Message read: " + event.getId());
+    }
+}

axon/src/main/java/com/baeldung/axon/events/MessageCreatedEvent.java

@@ -0,0 +1,20 @@
+package com.baeldung.axon.events;
+
+public class MessageCreatedEvent {
+ 
+    private final String id;
+    private final String text;
+ 
+    public MessageCreatedEvent(String id, String text) {
+        this.id = id;
+        this.text = text;
+    }
+ 
+    public String getId() {
+        return id;
+    }
+ 
+    public String getText() {
+        return text;
+    }
+}

axon/src/main/java/com/baeldung/axon/events/MessageReadEvent.java

@@ -0,0 +1,14 @@
+package com.baeldung.axon.events;
+
+public class MessageReadEvent {
+ 
+    private final String id;
+ 
+    public MessageReadEvent(String id) {
+        this.id = id;
+    }
+ 
+    public String getId() {
+        return id;
+    }
+}

axon/src/test/java/com/baeldung/axon/MessagesAggregateTest.java

@@ -0,0 +1,42 @@
+package com.baeldung.axon;
+
+import com.baeldung.axon.aggregates.MessagesAggregate;
+import com.baeldung.axon.commands.CreateMessageCommand;
+import com.baeldung.axon.commands.MarkReadMessageCommand;
+import com.baeldung.axon.events.MessageCreatedEvent;
+import com.baeldung.axon.events.MessageReadEvent;
+import org.axonframework.test.aggregate.AggregateTestFixture;
+import org.axonframework.test.aggregate.FixtureConfiguration;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.UUID;
+
+public class MessagesAggregateTest {
+
+    private FixtureConfiguration<MessagesAggregate> fixture;
+
+    @Before
+    public void setUp() throws Exception {
+        fixture = new AggregateTestFixture<MessagesAggregate>(MessagesAggregate.class);
+
+    }
+
+    @Test
+    public void giveAggregateRoot_whenCreateMessageCommand_thenShouldProduceMessageCreatedEvent() throws Exception {
+        String eventText = "Hello, how is your day?";
+        String id = UUID.randomUUID().toString();
+        fixture.given()
+                .when(new CreateMessageCommand(id, eventText))
+                .expectEvents(new MessageCreatedEvent(id, eventText));
+    }
+
+    @Test
+    public void givenMessageCreatedEvent_whenReadMessageCommand_thenShouldProduceMessageReadEvent() throws Exception {
+        String id = UUID.randomUUID().toString();
+
+        fixture.given(new MessageCreatedEvent(id, "Hello :-)"))
+                .when(new MarkReadMessageCommand(id))
+                .expectEvents(new MessageReadEvent(id));
+    }
+}

pom.xml

@@ -25,6 +25,7 @@
         <module>aspectj</module>
         <module>assertj</module>
         <module>autovalue</module>
+        <module>axon</module>
 
         <module>cdi</module>
         <!-- <module>core-java-9</module> -->