使用 spring-statemachine 状态机持久化时，可以通过内存、spring-statemachine-redis 或 spring-statemachine-data-jpa 现有方式持久化处理。

因项目审核操作记录频繁，数据量大，使用 内存 或 spring-statemachine-redis 模式不可取，而项目使用的是 MyBatis，使用 spring-statemachine-data-jpa 也不合适，需要自定义实现，简述步骤如下：

一、引入依赖

            <!--状态机--><dependency><groupId>org.springframework.statemachine</groupId><artifactId>spring-statemachine-starter</artifactId><version>2.2.3.RELEASE</version></dependency><dependency><groupId>org.springframework.statemachine</groupId><artifactId>spring-statemachine-kryo</artifactId><version>1.2.14.RELEASE</version></dependency>

二、创建持久化记录存储表

CREATE TABLE `state_machine_context` (`id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '自增主键',`machine_type` VARCHAR (32) DEFAULT '' COMMENT '状态机类型',`machine_id` VARCHAR (36) DEFAULT '' COMMENT '状态机ID',`machine_data` TINYBLOB COMMENT '状态机数据',`machine_state` VARCHAR (32) DEFAULT '' COMMENT '状态机状态',`machine_event` VARCHAR (36) DEFAULT '' COMMENT '状态机事件',`create_date` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',`update_date` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',PRIMARY KEY (`id`),KEY `idx_machine_id` (`machine_id`)
) ENGINE = INNODB COMMENT = '状态机上下文'

关键字段说明 

• machine_type：标记业务类型，如订单业务、用户业务
• macheine_id：业务数据ID，如订单ID、用户ID
• machine_data：状态机二进制数据

其它字段可根据自己业务需求自定义

三、自定义持久化类，即实现接口 StateMachinePersist

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
import org.apache.commons.lang3.tuple.Pair;
import org.springframework.messaging.MessageHeaders;
import org.springframework.statemachine.StateMachineContext;
import org.springframework.statemachine.StateMachinePersist;
import org.springframework.statemachine.kryo.MessageHeadersSerializer;
import org.springframework.statemachine.kryo.StateMachineContextSerializer;
import org.springframework.statemachine.kryo.UUIDSerializer;import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Date;
import java.util.Objects;
import java.util.Optional;
import java.util.UUID;/*** @author songjianyong*/
public class CustomStateMachinePersist<S, E> implements StateMachinePersist<S, E, Pair<String, String>> {private static final ThreadLocal<Kryo> KRYO_THREAD_LOCAL = ThreadLocal.withInitial(() -> {Kryo kryo = new Kryo();kryo.addDefaultSerializer(StateMachineContext.class, new StateMachineContextSerializer());kryo.addDefaultSerializer(MessageHeaders.class, new MessageHeadersSerializer());kryo.addDefaultSerializer(UUID.class, new UUIDSerializer());return kryo;});private byte[] serialize(StateMachineContext<S, E> context) {Kryo kryo = KRYO_THREAD_LOCAL.get();ByteArrayOutputStream out = new ByteArrayOutputStream();Output output = new Output(out);kryo.writeObject(output, context);output.close();return out.toByteArray();}@SuppressWarnings("unchecked")private StateMachineContext<S, E> deserialize(byte[] data) {if (data == null || data.length == 0) {return null;}Kryo kryo = KRYO_THREAD_LOCAL.get();ByteArrayInputStream in = new ByteArrayInputStream(data);Input input = new Input(in);return kryo.readObject(input, StateMachineContext.class);}private final StateMachineContextDao stateMachineContextDao;public SongStateMachinePersist(StateMachineContextDao stateMachineContextDao) {this.stateMachineContextDao = stateMachineContextDao;}@Overridepublic void write(StateMachineContext<S, E> context, Pair<String, String> pair) throws Exception {byte[] machineData = serialize(context);String machineId = pair.getKey();String machineType = pair.getValue();StateMachineContextEntity stateMachineContexEntity = stateMachinePersistDao.findByMachineIdAndMachineType(machineId, machineType);if (Objects.nonNull(stateMachineContexEntity)) {stateMachineContexEntity.setMachineData(machineData);stateMachineContexEntity.setMachineState(Optional.ofNullable(context.getState()).map(Objects::toString).orElse(stateMachineContexEntity.getMachineState()));stateMachineContexEntity.setMachineEvent(Optional.ofNullable(context.getEvent()).map(Objects::toString).orElse(stateMachineContexEntity.getMachineEvent()));stateMachineContexEntity.setUpdateDate(new Date());stateMachineContextDao.updateById(stateMachineContexEntity);return;}StateMachineContextEntity entity = new StateMachineContextEntity();entity.setMachineId(machineId);entity.setMachineData(machineData);entity.setMachineType(machineType);entity.setMachineState(Optional.ofNullable(context.getState()).map(Objects::toString).orElse(null));entity.setMachineEvent(Optional.ofNullable(context.getEvent()).map(Objects::toString).orElse(null));stateMachineContextDao.save(entity);}@Overridepublic StateMachineContext<S, E> read(Pair<String, String> pair) throws Exception {String machineId = pair.getKey();String machineType = pair.getValue();StateMachineContextEntity stateMachineContexEntity = stateMachineContextDao.findByMachineIdAndMachineType(machineId, machineType);if (Objects.isNull(stateMachineContexEntity)) {return null;}byte[] machineData = stateMachineContexEntity.getMachineData();return deserialize(machineData);}
}

四、自定义状态机，即继承类 AbstractStateMachinePersister

import org.apache.commons.lang3.tuple.Pair;
import org.springframework.statemachine.StateMachinePersist;
import org.springframework.statemachine.persist.AbstractStateMachinePersister;/*** @author songjianyong*/
public class CustomStateMachinePersister<S, E> extends AbstractStateMachinePersister<S, E, Pair<String, String>> {public CustomStateMachinePersister(StateMachinePersist<S, E, Pair<String, String>> stateMachinePersist) {super(stateMachinePersist);}
}

五、使用自定义状态机

    /*** 持久化到库中** @return 数据库持久化状态机*/@Bean(name = "customStateMachinePersister")public CustomStateMachinePersister<S, E> customStateMachinePersister(StateMachineContextDao stateMachineContextDao) {CustomStateMachinePersist<S, E> customStateMachinePersist = new CustomStateMachinePersist<>(stateMachineContextDao);return new CustomStateMachinePersister<>(customStateMachinePersist);}

    @Resourceprivate StateMachinePersister<OrderStatus, OrderStatusChangeEvent, Pair<String, String> pair> customStateMachinePersister;