在Scala中实现JPA查询

我正在尝试为Scala实现JPA,如下所示 these examples 用Java编写。

jpaApi.withTransaction :

class ManageBanks @Inject() (jpaApi: JPAApi) extends Controller {

   @Transactional
   def readMany = {
      val em = jpaApi.em

      jpaApi.withTransaction( em -> {   //  <-- error in this line
          val query = em.createQuery("from BankHib order by name")
          val list = query.getResultList.asScala.toList.map(_.asInstanceOf[BankHib])
          list
      })
   }
}

错误:

带有可选项的事务的重载方法值:(x$1: [T] (x 1美元: Java语言util。作用函数[javax.persistence.EntityManager,T])T 列表[admin.manage.BankHib])