Spring Statemachine结合JPA对接RDBMS持久化完整配置及示例代码求助

前置依赖 #

以Maven为例引入所需依赖：

<!-- Spring Statemachine核心 -->
<dependency>
    <groupId>org.springframework.statemachine</groupId>
    <artifactId>spring-statemachine-core</artifactId>
    <version>3.2.0</version>
</dependency>
<!-- Spring Statemachine JDBC持久化支持 -->
<dependency>
    <groupId>org.springframework.statemachine</groupId>
    <artifactId>spring-statemachine-jdbc</artifactId>
    <version>3.2.0</version>
</dependency>
<!-- MySQL驱动 -->
<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <scope>runtime</scope>
</dependency>
<!-- JDBC数据源，Spring Boot项目自带，非Boot项目需额外引入 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

1. 初始化数据库表结构 #

Spring Statemachine JDBC模块默认使用以下表结构存储状态机上下文，直接在MySQL库中执行即可：

CREATE TABLE IF NOT EXISTS spring_statemachine (
  machine_id VARCHAR(255) NOT NULL,
  state VARCHAR(255) DEFAULT NULL,
  state_machine_context BLOB DEFAULT NULL,
  PRIMARY KEY (machine_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

如需存储扩展状态等复杂信息，可自行调整字段长度或新增自定义字段，默认结构可覆盖大部分常规场景。

2. 基础枚举定义 #

先定义状态机的状态和事件枚举，以下以订单状态机为例：

// 订单状态枚举
public enum OrderState {
    CREATED, PAID, DELIVERED, COMPLETED, CANCELLED
}

// 订单事件枚举
public enum OrderEvent {
    PAY, DELIVER, COMPLETE, CANCEL
}

3. 核心配置类 #

3.1 数据源配置（application.yml） #

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/statemachine_demo?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8
    username: root
    password: 你的数据库密码
    driver-class-name: com.mysql.cj.jdbc.Driver

3.2 状态机持久化配置 #

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.statemachine.StateMachinePersist;
import org.springframework.statemachine.config.EnableStateMachine;
import org.springframework.statemachine.config.StateMachineConfigurerAdapter;
import org.springframework.statemachine.config.builders.StateMachineConfigurationConfigurer;
import org.springframework.statemachine.config.builders.StateMachineStateConfigurer;
import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;
import org.springframework.statemachine.jdbc.JdbcStateMachineRepository;
import org.springframework.statemachine.persist.DefaultStateMachinePersister;
import org.springframework.statemachine.persist.RepositoryStateMachinePersist;
import org.springframework.statemachine.persist.StateMachinePersister;
import javax.sql.DataSource;
import java.util.EnumSet;

@Configuration
@EnableStateMachine
public class StateMachineConfig extends StateMachineConfigurerAdapter<OrderState, OrderEvent> {

    private final DataSource dataSource;

    public StateMachineConfig(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    // 配置JDBC存储仓库
    @Bean
    public JdbcStateMachineRepository<OrderState, OrderEvent> jdbcStateMachineRepository() {
        JdbcStateMachineRepository<OrderState, OrderEvent> repository = 
            new JdbcStateMachineRepository<>(new JdbcTemplate(dataSource));
        // 如需自定义表名可打开以下配置，默认表名为spring_statemachine
        // repository.setTableName("custom_statemachine_table");
        return repository;
    }

    // 配置持久化处理器
    @Bean
    public StateMachinePersist<OrderState, OrderEvent, String> stateMachinePersist() {
        return new RepositoryStateMachinePersist<>(jdbcStateMachineRepository());
    }

    // 配置持久化工具类，第三个泛型参数为业务唯一标识，示例中为订单ID
    @Bean
    public StateMachinePersister<OrderState, OrderEvent, String> stateMachinePersister() {
        return new DefaultStateMachinePersister<>(stateMachinePersist());
    }

    // 状态配置
    @Override
    public void configure(StateMachineStateConfigurer<OrderState, OrderEvent> states) throws Exception {
        states
            .withStates()
            .initial(OrderState.CREATED)
            .states(EnumSet.allOf(OrderState.class));
    }

    // 状态流转配置
    @Override
    public void configure(StateMachineTransitionConfigurer<OrderState, OrderEvent> transitions) throws Exception {
        transitions
            .withExternal()
            .source(OrderState.CREATED).target(OrderState.PAID).event(OrderEvent.PAY)
            .and()
            .withExternal()
            .source(OrderState.PAID).target(OrderState.DELIVERED).event(OrderEvent.DELIVER)
            .and()
            .withExternal()
            .source(OrderState.DELIVERED).target(OrderState.COMPLETED).event(OrderEvent.COMPLETE)
            .and()
            .withExternal()
            .source(OrderState.CREATED).target(OrderState.CANCELLED).event(OrderEvent.CANCEL);
    }

    // 基础配置
    @Override
    public void configure(StateMachineConfigurationConfigurer<OrderState, OrderEvent> config) throws Exception {
        config
            .withConfiguration()
            .autoStartup(true);
    }
}

4. 业务层使用示例 #

import org.springframework.statemachine.StateMachine;
import org.springframework.statemachine.persist.StateMachinePersister;
import org.springframework.stereotype.Service;

@Service
public class OrderService {

    private final StateMachine<OrderState, OrderEvent> stateMachine;
    private final StateMachinePersister<OrderState, OrderEvent, String> persister;

    public OrderService(StateMachine<OrderState, OrderEvent> stateMachine, 
                       StateMachinePersister<OrderState, OrderEvent, String> persister) {
        this.stateMachine = stateMachine;
        this.persister = persister;
    }

    // 新建订单时初始化状态机并持久化
    public void createOrder(String orderId) throws Exception {
        stateMachine.stop();
        stateMachine.start();
        persister.persist(stateMachine, orderId);
    }

    // 触发事件并更新持久化状态
    public void triggerEvent(String orderId, OrderEvent event) throws Exception {
        // 从数据库恢复对应订单的状态机上下文
        persister.restore(stateMachine, orderId);
        // 发送事件触发状态流转
        stateMachine.sendEvent(event);
        // 持久化更新后的状态机上下文
        persister.persist(stateMachine, orderId);
    }

    // 查询当前订单状态
    public OrderState getCurrentState(String orderId) throws Exception {
        persister.restore(stateMachine, orderId);
        return stateMachine.getState().getId();
    }
}

注意事项 #

• Spring Statemachine版本需要和当前项目的Spring Boot版本兼容，3.x版本对应Spring Boot 3.x，2.x版本对应Spring Boot 2.x
• 如果需要存储扩展状态中的自定义对象，需要确保对象实现了序列化接口

内容的提问来源于stack exchange，提问作者nk_melb