在 AKKA Cluster Sharding 中，可以定义多个实体角色，每种实体角色都有独立的状态和行为。我们可以在同一个集群中同时使用不同类型的实体角色。

一种方式是通过为每种实体角色定义不同的实体类型。下面是一个示例，其中我们定义了两种不同类型的实体角色：“user”和“order”。

// 实体 trait
trait Entity {
  val id: String
}

// User 实体
case class UserEntity(id: String, name: String) extends Entity

// Order 实体
case class OrderEntity(id: String, product: String, quantity: Int) extends Entity

// User 实体 actor
class UserActor extends Actor with ActorLogging {
  var state: UserEntity = _
  def receive = {
    case UpdateUser(newUser) =>
      state = newUser
      log.info("User updated: {}", state)
    case GetUser =>
      sender() ! state
  }
}

// Order 实体 actor
class OrderActor extends Actor with ActorLogging {
  var state: OrderEntity = _
  def receive = {
    case UpdateOrder(newOrder) =>
      state = newOrder
      log.info("Order updated: {}", state)
    case GetOrder =>
      sender() ! state
  }
}

// 实体角色类型
sealed trait EntityType
case object UserEntityType extends EntityType
case object OrderEntityType extends EntityType

// 实体启动器
object EntityLauncher {
  def launch(system: ActorSystem, entityType: EntityType, entityId: String): ActorRef = {
    entityType match {
      case UserEntityType =>
        ClusterSharding(system).start(
          typeName = "User",
          entityProps = Props[UserActor],
          settings = ClusterShardingSettings(system),
          extractEntityId = extractUserId,
          extractShardId = extractShardId
        )
      case OrderEntityType =>
        ClusterSharding(system).start(
          typeName = "Order",
          entityProps = Props[OrderActor],
          settings = ClusterShardingSettings(system),
          extractEntityId = extractOrderId,
          extractShardId = extractShardId
        )
    }
  }

  // 提取实体 ID
  def extractUserId: ShardRegion.ExtractEntityId = {
    case updateUser: UpdateUser => (updateUser.id, updateUser)
    case getUser: GetUser => (getUser.id, getUser)
  }

  def extractOrderId: ShardRegion.ExtractEntityId = {
    case updateOrder: UpdateOrder => (updateOrder.id, updateOrder)
    case getOrder: GetOrder => (getOrder.id, getOrder)
  }

  // 提取分片