/*
* 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.tasks;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.Map;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.task.TaskExecutor;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.shell.Bootstrap;
import org.springframework.statemachine.StateContext;
import org.springframework.statemachine.StateMachineSystemConstants;
import org.springframework.statemachine.action.Action;
import org.springframework.statemachine.annotation.OnTransition;
import org.springframework.statemachine.config.EnableStateMachine;
import org.springframework.statemachine.config.EnumStateMachineConfigurerAdapter;
import org.springframework.statemachine.config.builders.StateMachineStateConfigurer;
import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;
import org.springframework.statemachine.guard.Guard;
import org.springframework.util.ObjectUtils;
@Configuration
public class Application {
@Configuration
@EnableStateMachine
static class StateMachineConfig
extends EnumStateMachineConfigurerAdapter<States, Events> {
//tag::snippetAA[]
@Override
public void configure(StateMachineStateConfigurer<States, Events> states)
throws Exception {
states
.withStates()
.initial(States.READY)
.fork(States.FORK)
.state(States.TASKS)
.join(States.JOIN)
.choice(States.CHOICE)
.state(States.ERROR)
.and()
.withStates()
.parent(States.TASKS)
.initial(States.T1)
.end(States.T1E)
.and()
.withStates()
.parent(States.TASKS)
.initial(States.T2)
.end(States.T2E)
.and()
.withStates()
.parent(States.TASKS)
.initial(States.T3)
.end(States.T3E)
.and()
.withStates()
.parent(States.ERROR)
.initial(States.AUTOMATIC)
.state(States.AUTOMATIC, automaticAction(), null)
.state(States.MANUAL);
}
//end::snippetAA[]
//tag::snippetAB[]
@Override
public void configure(StateMachineTransitionConfigurer<States, Events> transitions)
throws Exception {
transitions
.withExternal()
.source(States.READY).target(States.FORK)
.event(Events.RUN)
.and()
.withFork()
.source(States.FORK).target(States.TASKS)
.and()
.withExternal()
.source(States.T1).target(States.T1E)
.and()
.withExternal()
.source(States.T2).target(States.T2E)
.and()
.withExternal()
.source(States.T3).target(States.T3E)
.and()
.withJoin()
.source(States.TASKS).target(States.JOIN)
.and()
.withExternal()
.source(States.JOIN).target(States.CHOICE)
.and()
.withChoice()
.source(States.CHOICE)
.first(States.ERROR, tasksChoiceGuard())
.last(States.READY)
.and()
.withExternal()
.source(States.ERROR).target(States.READY)
.event(Events.CONTINUE)
.and()
.withExternal()
.source(States.AUTOMATIC).target(States.MANUAL)
.event(Events.FALLBACK)
.and()
.withInternal()
.source(States.MANUAL)
.action(fixAction())
.event(Events.FIX);
}
//end::snippetAB[]
//tag::snippetAC[]
@Bean
public Guard<States, Events> tasksChoiceGuard() {
return new Guard<States, Events>() {
@Override
public boolean evaluate(StateContext<States, Events> context) {
Map<Object, Object> variables = context.getExtendedState().getVariables();
return !(ObjectUtils.nullSafeEquals(variables.get("T1"), true)
&& ObjectUtils.nullSafeEquals(variables.get("T2"), true)
&& ObjectUtils.nullSafeEquals(variables.get("T3"), true));
}
};
}
//end::snippetAC[]
//tag::snippetAD[]
@Bean
public Action<States, Events> automaticAction() {
return new Action<States, Events>() {
@Override
public void execute(StateContext<States, Events> context) {
Map<Object, Object> variables = context.getExtendedState().getVariables();
if (ObjectUtils.nullSafeEquals(variables.get("T1"), true)
&& ObjectUtils.nullSafeEquals(variables.get("T2"), true)
&& ObjectUtils.nullSafeEquals(variables.get("T3"), true)) {
context.getStateMachine().sendEvent(Events.CONTINUE);
} else {
context.getStateMachine().sendEvent(Events.FALLBACK);
}
}
};
}
@Bean
public Action<States, Events> fixAction() {
return new Action<States, Events>() {
@Override
public void execute(StateContext<States, Events> context) {
Map<Object, Object> variables = context.getExtendedState().getVariables();
variables.put("T1", true);
variables.put("T2", true);
variables.put("T3", true);
context.getStateMachine().sendEvent(Events.CONTINUE);
}
};
}
//end::snippetAD[]
@Bean
public Tasks tasks() {
return new Tasks();
}
//tag::snippetAE[]
@Bean(name = StateMachineSystemConstants.TASK_EXECUTOR_BEAN_NAME)
public TaskExecutor taskExecutor() {
ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
taskExecutor.setCorePoolSize(5);
return taskExecutor;
}
//end::snippetAE[]
}
//tag::snippetB[]
public enum States {
READY,
FORK, JOIN, CHOICE,
TASKS, T1, T1E, T2, T2E, T3, T3E,
ERROR, AUTOMATIC, MANUAL
}
//end::snippetB[]
//tag::snippetC[]
public enum Events {
RUN, FALLBACK, CONTINUE, FIX;
}
//end::snippetC[]
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@OnTransition
public @interface StatesOnTransition {
States[] source() default {};
States[] target() default {};
}
public static void main(String[] args) throws Exception {
Bootstrap.main(args);
}
}