Spring Statemachine Construct Statemachine

StateMachineModel
这里的Model跟MVC模式里的Model是一个意义，是数据模型的意思；在Spring StateMachine内部，各种形式的状态及的配置首先被转换为StateMachineModel模块的表示；

Spring Statemachine使用StateMachineModel蚩尤的信息，构建Statemachine对象；
StateMachineModel->StateMachine的逻辑可以在StateMachineFactory接口的抽象实现AbstractStateMachineFactory中了解到具体细节。

Spring Statemachine提供了4中提供状态及配置的方式

1. Java configuration
2. UML（UmlStateMachineModelFactory）
3. A repository（RepositoryStateMachineModelFactory，spring-statemachine-data-jpa，spring-statemachine-data-redis，spring-statemachine-data-mongodb）
4. custom StateMachineModel，前三中方式提供的配置信息最终都会转换为StateMachineModel

A machine can be built from Java configuration, UML, or a repository. If you want to go crazy, you can also use a custom StateMachineModel, which is the lowest possible level at which to define configuration.

Spring Statemachine中还有一个persist模块，persist是用来持久花StateMachineContext对象的，也就是persist持久花的是一个Statemachine的运行时信息；上面提到的repository是持久花的配置信息。

Spring Statemachine从repository读取配置信息，构建StatemachineModel配置模型，StatemachineFactory蚩尤StateMachineModelFactory对象的引用，通过StatemachineModel提供的信息构建Statemachine，Statemachine的运行时信息可以通过persist模块持久花到对应的存储，Spring Statemachine默认提供了redis，jpa和mangodb三种持久花方式；

Spring Statemachine提供的data模块同时提供了Statemachine配置信息和运行时信息的持久花能力
spring-statemachine-data-common
spring-statemachine-data-jpa
spring-statemachine-data-redis
spring-statemachine-data-mongodb

StateMachineBuilder

public static StateMachine<String, String> buildMachine(BeanFactory beanFactory) throws Exception {
	Builder<String, String> builder = StateMachineBuilder.builder();

	builder.configureConfiguration()
		.withConfiguration()
			.machineId("myMachineId")
			.beanFactory(beanFactory);

	builder.configureStates()
		.withStates()
			.initial("S1")
			.state("S2");

	builder.configureTransitions()
		.withExternal()
			.source("S1")
			.target("S2")
			.event("E1");

	return builder.build();
}

Custom StateMachineModel

// setup configuration data
ConfigurationData<String, String> configurationData = new ConfigurationData<>();

// setup states data
Collection<StateData<String, String>> stateData = new ArrayList<>();
stateData.add(new StateData<String, String>("S1", true));
stateData.add(new StateData<String, String>("S2"));
StatesData<String, String> statesData = new StatesData<>(stateData);

// setup transitions data
Collection<TransitionData<String, String>> transitionData = new ArrayList<>();
transitionData.add(new TransitionData<String, String>("S1", "S2", "E1"));
TransitionsData<String, String> transitionsData = new TransitionsData<>(transitionData);

// setup model
StateMachineModel<String, String> stateMachineModel = new DefaultStateMachineModel<>(configurationData, statesData,
		transitionsData);

// instantiate machine via factory
ObjectStateMachineFactory<String, String> factory = new ObjectStateMachineFactory<>(stateMachineModel);
StateMachine<String, String> stateMachine = factory.getStateMachine();