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/zookeeper/spring-statemachine-samples-zookeeper.gradle

@@ -9,5 +9,5 @@ dependencies {
 	implementation project(':spring-statemachine-zookeeper')
 	implementation project(':spring-statemachine-samples-common')
 	implementation project(':spring-statemachine-core')
-	implementation 'org.springframework.shell:spring-shell-core'
+	implementation 'org.springframework.boot:spring-boot-starter'
 }

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

@@ -19,6 +19,7 @@ import org.apache.curator.framework.CuratorFramework;
 import org.apache.curator.framework.CuratorFrameworkFactory;
 import org.apache.curator.retry.ExponentialBackoffRetry;
 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.statemachine.config.EnableStateMachine;
@@ -29,7 +30,7 @@ import org.springframework.statemachine.config.builders.StateMachineTransitionCo
 import org.springframework.statemachine.ensemble.StateMachineEnsemble;
 import org.springframework.statemachine.zookeeper.ZookeeperStateMachineEnsemble;
 
-@Configuration
+@SpringBootApplication(scanBasePackages = "demo")
 public class Application  {
 
 	@Configuration

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

@@ -15,22 +15,30 @@
  */
 package demo.zookeeper;
 
+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 reactor.core.publisher.Mono;
 
-@Command
+@Configuration
 public class StateMachineCommands extends AbstractStateMachineCommands<String, String> {
 
-	@Command(command = "sm event", description = "Sends an event to a state machine")
-	public String event(@Option(longNames = { "", "event" }, required = true, description = "The event") final String 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) {
+				String event = args[0];
+				getStateMachine()
+						.sendEvent(Mono.just(MessageBuilder
+								.withPayload(event).build()))
+						.subscribe();
+				return "Event " + event + " sent";
+			}
+		};
 	}
 }

spring-statemachine-samples/zookeeper/src/main/resources/META-INF/spring/spring-shell-plugin.xml

@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<beans xmlns="http://www.springframework.org/schema/beans"
-	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xmlns:context="http://www.springframework.org/schema/context"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
-		http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
-	<context:component-scan base-package="demo" />
-</beans>

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

@@ -0,0 +1 @@
+spring.main.allow-bean-definition-overriding=true