Remove dependency to Spring Shell

This commit updates the samples to use Java's
standard CLI utilities instead of Spring Shell.

Resolves #1184

spring-statemachine-samples/showcase/src/main/java/demo/showcase/Application.java

@@ -23,7 +23,6 @@ import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.shell.command.annotation.CommandScan;
 import org.springframework.statemachine.StateContext;
 import org.springframework.statemachine.action.Action;
 import org.springframework.statemachine.config.EnableStateMachine;
@@ -32,7 +31,6 @@ import org.springframework.statemachine.config.builders.StateMachineStateConfigu
 import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;
 import org.springframework.statemachine.guard.Guard;
 
-@CommandScan
 @SpringBootApplication(scanBasePackages = "demo")
 public class Application  {
 

spring-statemachine-samples/showcase/src/main/java/demo/showcase/StateMachineCommands.java

@@ -15,24 +15,32 @@
  */
 package demo.showcase;
 
+import demo.BasicCommand;
+import demo.Command;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 import org.springframework.messaging.support.MessageBuilder;
-import org.springframework.shell.command.annotation.Command;
-import org.springframework.shell.command.annotation.Option;
 
 import demo.AbstractStateMachineCommands;
 import demo.showcase.Application.Events;
 import demo.showcase.Application.States;
 import reactor.core.publisher.Mono;
 
-@Command
+@Configuration
 public class StateMachineCommands extends AbstractStateMachineCommands<States, Events> {
 
-	@Command(command = "sm event", description = "Sends an event to a state machine")
-	public String event(@Option(longNames = { "", "event" }, required = true, description = "The event") final Events event) {
-		getStateMachine()
-			.sendEvent(Mono.just(MessageBuilder
-				.withPayload(event).build()))
-			.subscribe();
-		return "Event " + event + " send";
+	@Bean
+	public Command event() {
+		return new BasicCommand("event", "Sends an event to a state machine") {
+			@Override
+			public String execute(String[] args) {
+				Events event = Events.valueOf(args[0]);
+				getStateMachine()
+						.sendEvent(Mono.just(MessageBuilder
+								.withPayload(event).build()))
+						.subscribe();
+				return "Event " + event + " sent";
+			}
+		};
 	}
 }

spring-statemachine-samples/showcase/src/main/resources/application.properties

@@ -1 +1 @@
-spring.shell.interactive.enabled=true
+spring.main.allow-bean-definition-overriding=true