BAEL-2435 Add a GUI

-Add spring-boot-starter-web to support rest endpoints
-Add a rest endpoint to spoof some form of UI to publish a message, as
the old main will no longer publish the commands upon start up

axon/pom.xml

@@ -39,6 +39,11 @@
             <version>2.1.1.RELEASE</version>
             <scope>compile</scope>
         </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
     </dependencies>
 
     <properties>

axon/src/main/java/com/baeldung/axon/gui/MessagesRestEndpoint.java

@@ -0,0 +1,28 @@
+package com.baeldung.axon.gui;
+
+import java.util.UUID;
+
+import org.axonframework.commandhandling.gateway.CommandGateway;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.axon.coreapi.commands.CreateMessageCommand;
+import com.baeldung.axon.coreapi.commands.MarkReadMessageCommand;
+
+@RestController
+public class MessagesRestEndpoint {
+
+    private final CommandGateway commandGateway;
+
+    public MessagesRestEndpoint(CommandGateway commandGateway) {
+        this.commandGateway = commandGateway;
+    }
+
+    @PostMapping("/hello")
+    public void publishMessages() {
+        final String itemId = UUID.randomUUID().toString();
+        commandGateway.send(new CreateMessageCommand(itemId, "Hello, how is your day? :-)"));
+        commandGateway.send(new MarkReadMessageCommand(itemId));
+    }
+
+}