StateMachineConfig.java

/*
 * Copyright 2015 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package demo.scope;

import java.io.IOException;
import java.io.InputStream;
import java.util.EnumSet;
import java.util.Scanner;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;
import org.springframework.context.annotation.ScopedProxyMode;
import org.springframework.core.io.ClassPathResource;
import org.springframework.statemachine.config.EnableStateMachine;
import org.springframework.statemachine.config.EnumStateMachineConfigurerAdapter;
import org.springframework.statemachine.config.builders.StateMachineConfigurationConfigurer;
import org.springframework.statemachine.config.builders.StateMachineStateConfigurer;
import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;

@Configuration
public class StateMachineConfig {

	@Configuration
	@EnableStateMachine
	@Scope(scopeName="session", proxyMode=ScopedProxyMode.TARGET_CLASS)
	static class Config
			extends EnumStateMachineConfigurerAdapter<States, Events> {

		@Override
		public void configure(StateMachineConfigurationConfigurer<States, Events> config)
				throws Exception {
			config
				.withConfiguration()
					.autoStartup(true);
		}

		@Override
		public void configure(StateMachineStateConfigurer<States, Events> states)
				throws Exception {
			states
				.withStates()
					.initial(States.S0)
					.states(EnumSet.allOf(States.class));
		}

		@Override
		public void configure(StateMachineTransitionConfigurer<States, Events> transitions)
				throws Exception {
			transitions
				.withExternal()
					.source(States.S0).target(States.S1).event(Events.A)
					.and()
				.withExternal()
					.source(States.S1).target(States.S2).event(Events.B)
					.and()
				.withExternal()
					.source(States.S2).target(States.S0).event(Events.C);
		}

	}

	@Bean
	public String stateChartModel() throws IOException {
		ClassPathResource model = new ClassPathResource("statechartmodel.txt");
		InputStream inputStream = model.getInputStream();
		Scanner scanner = new Scanner(inputStream);
		String content = scanner.useDelimiter("\\Z").next();
		scanner.close();
		return content;
	}

	public enum States {
		S0, S1, S2;
	}

	public enum Events {
		A, B, C;
	}

}