下面是一个示例代码，演示了如何使用Akka将事件持久化到Cassandra并发布到Kafka多个事件：

import akka.actor.{ActorSystem, Props}
import akka.persistence.PersistentActor
import com.datastax.driver.core.{Cluster, Session}
import org.apache.kafka.clients.producer.{KafkaProducer, ProducerConfig, ProducerRecord}
import java.util.Properties
import scala.collection.JavaConverters._

// 定义事件
case class Event(data: String)

// 定义持久化事件的Actor
class EventPersistenceActor extends PersistentActor {
  override def persistenceId: String = "event-persistence-actor"

  var events: List[Event] = Nil

  override def receiveCommand: Receive = {
    case event: Event =>
      // 将事件保存到Cassandra
      persist(event) { persistedEvent =>
        events = persistedEvent :: events
        // 发布事件到Kafka
        publishToKafka(persistedEvent)
      }
  }

  override def receiveRecover: Receive = {
    case event: Event =>
      events = event :: events
  }

  def publishToKafka(event: Event): Unit = {
    val topic = "events-topic"
    val props = new Properties()
    props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092")
    props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer")
    props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer")

    val producer = new KafkaProducer[String, String](props)
    val record = new ProducerRecord[String, String](topic, event.data)
    producer.send(record)
    producer.close()
  }
}

object Main extends App {
  // 创建Cassandra连接
  val cluster = Cluster.builder().addContactPoint("localhost").build()
  val session: Session = cluster.connect()
  session.execute("CREATE KEYSPACE IF NOT EXISTS test WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '1'}")
  session.execute("CREATE TABLE IF NOT EXISTS test.events (id UUID PRIMARY KEY, data text)")

  // 创建Actor系统
  val system = ActorSystem("event-persistence-system")
  val eventPersistenceActor = system.actorOf(Props[EventPersistenceActor], "event-persistence-actor")

  // 发送事件到Actor
  eventPersistenceActor ! Event("Event 1")
  eventPersistenceActor ! Event("Event 2")
  eventPersistenceActor ! Event("Event 3")

  // 关闭Cassandra连接
  session.close()
  cluster.close()
}

这个示例代码假设你已经在本地安装了Cassandra和Kafka，并且它们分别在默认端口运行。代码中创建了一个EventPersistenceActor，它将事件持久化到Cassandra，并在持久化后将事件发布到Kafka。Main对象创建了一个Actor系统，并向EventPersistenceActor发送了几个事件。你可以根据自己的需求修改和扩展这个示例代码。