状态机简介
状态机是一种用来进行对象行为建模的工具，其作用主要是描述对象在它的生命周期内所经历的状态序列，以及如何响应来自外界的各种事件,摘录自这个大神的文章状态机引擎选型
示例说明
网上能找到的示例大多都过于复杂,所以写了一个简单的示例下面的代码定义了一个极简的状态机,仅包含两个状态(上班,下班),一个事件(通勤),通过web页面操作添加状态机及状态转换,集成了spring-statemachine-data-jpa进行持久化.
SpringBoot2.x配置说明
- Pom.xml
<dependency> <groupId>org.springframework.statemachine</groupId> <artifactId>spring-statemachine-starter</artifactId> <version>2.2.0.RELEASE</version> </dependency> <dependency> <groupId>org.springframework.statemachine</groupId> <artifactId>spring-statemachine-data-jpa</artifactId> <version>2.2.0.RELEASE</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency>
java配置
- 状态机持久化
@Configuration public class StateMachineJpaConfig { /** * StateMachineRuntimePersister为状态机运行时持久化配置 * @param jpaStateMachineRepository * @return */ @Bean public StateMachineRuntimePersister<String, String, String> stateMachineRuntimePersister( JpaStateMachineRepository jpaStateMachineRepository) { return new JpaPersistingStateMachineInterceptor<>(jpaStateMachineRepository); } /** * StateMachineService为状态状态机持久化控制,用于获取或关闭状态机 * @param stateMachineFactory * @param stateMachineRuntimePersister * @return */ @Bean public StateMachineService<String, String> stateMachineService( StateMachineFactory<String, String> stateMachineFactory, StateMachineRuntimePersister<String, String, String> stateMachineRuntimePersister) { return new DefaultStateMachineService<String, String>(stateMachineFactory, stateMachineRuntimePersister); } }
- 状态机监听 继承StateMachineListenerAdapter重写需监听的方法即可,通过方法名可推测监听的事件,就不贴代码了.
- 状态机配置,@EnableStateMachine为单例模式并不适合此示例所以使用@EnableStateMachineFactory
@Configuration @EnableStateMachineFactory public class StateMachineConfig extends StateMachineConfigurerAdapter<String, String> { @Autowired private StateMachineRuntimePersister<String, String, String> stateMachineRuntimePersister; @Autowired private StateMachineLogListener logListener; @Override public void configure(StateMachineConfigurationConfigurer<String, String> config) throws Exception { config .withPersistence() .runtimePersister(stateMachineRuntimePersister) .and() .withConfiguration().listener(logListener); } @Override public void configure(StateMachineStateConfigurer<String, String> states) throws Exception { states .withStates() .initial("宿舍") .state("公司"); } @Override public void configure(StateMachineTransitionConfigurer<String, String> transitions) throws Exception { transitions .withExternal() .source("宿舍").target("公司") .event("通勤") .and() .withExternal() .source("公司").target("宿舍") .event("通勤"); } }
示例代码
https://gitee.com/MeiJM/spring-cram/tree/master/statemachine
参考资料
https://docs.spring.io/spring-statemachine/docs/2.2.0.RELEASE/reference/#preface
