scala - 从案例类集合创建 Flink DataStream 时“未找到隐含”

Question

我正在尝试做一个scala api hello world 但无法复制从https://www.slideshare.net/dataArtisans/apache-flink-datastream-api-basics/20flink看到的开始教程片段

我尝试的副本是：

  val env = StreamExecutionEnvironment.getExecutionEnvironment
  case class Order(user: String, product: String, amount: Double, proctime: Int, rowtime: Int)

  def basic() = {
    val seq = (1 to 50).map { i => Order(s"User" + (i % 10).toString, "Product" + (i % 20), 2.0 * (4 * i +.5 * i * i -.1 * i * i * i), i * 10, i * 3) }
    val ds: DataStream[Order] = env.fromElements(seq:_*)

然而，隐含的不起作用，给

错误：(21, 30) 找不到类型为 org.apache.flink.api.common.typeinfo.TypeInformation[com.blazedb.spark.FlinkDemo.Order] 的证据参数的隐式值

这里需要改变什么？

标签： scalaapache-flinkimplicit

Answer 1

做就是了

import org.apache.flink.streaming.api.scala._

为了导入隐式TypeInformation[T]

https://github.com/apache/flink/blob/master/flink-scala/src/main/scala/org/apache/flink/api/scala/package.scala#L49