spring-statemachine 状态机自定义持久化入库

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

            
            <dependency>
                <groupId>org.springframework.statemachinegroupId>
                <artifactId>spring-statemachine-starterartifactId>
                <version>2.2.3.RELEASEversion>
            dependency>
            
            <dependency>
                <groupId>org.springframework.statemachinegroupId>
                <artifactId>spring-statemachine-kryoartifactId>
                <version>1.2.14.RELEASEversion>
            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 implements StateMachinePersist> {
    private static final ThreadLocal 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 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 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;
    }
 
    @Override
    public void write(StateMachineContext context, Pair 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);
    }
 
    @Override
    public StateMachineContext read(Pair 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 extends AbstractStateMachinePersister> {
    
    public CustomStateMachinePersister(StateMachinePersist> 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 customStateMachinePersister(StateMachineContextDao stateMachineContextDao) {
        CustomStateMachinePersist customStateMachinePersist = new CustomStateMachinePersist<>(stateMachineContextDao);
        return new CustomStateMachinePersister<>(customStateMachinePersist);
    }

    @Resource
    private StateMachinePersister pair> customStateMachinePersister;