Scala：在函数接口中使用隐式

Question

在 Scala 中你可以写一个像这样的函数：

object Add extends ((Int, Int) => Int) {
  def apply(a: Int, b: Int) = a + b
}

我想写一个像上面的函数，但我也想使用imlicit。类似于：

object DoSomething extends (Configuration, ??? => Dataframe) {
  override def apply(config: Configuration)(implicit sparkSession: SparkSession): DataFrame = {
    ...
  }
}

有谁知道，我该怎么做？

编辑：

object DoSomething extends (Configuration => SparkSession) {
  override def apply(config: Configuration)(implicit sparkSession: SparkSession): DataFrame = {
    val bootstrapServers = configuration.bootstrapServers
    val topic = configuration.topic

    sparkSession.readStream
      .format("kafka")
      .option("kafka.bootstrap.servers", bootstrapServers)
      .option("subscribe", topic)
      .load()
  }
}

Answer 1

尝试

class DoSomething(implicit sparkSession: SparkSession) extends (Configuration => DataFrame) {
  override def apply(config: Configuration): DataFrame = {
    val bootstrapServers = configuration.bootstrapServers
    val topic = configuration.topic

    sparkSession.readStream
      .format("kafka")
      .option("kafka.bootstrap.servers", bootstrapServers)
      .option("subscribe", topic)
      .load()
  }
}

Scala：在函数接口中使用隐式

Scala: Use implicits in with Function interface

scala

function

implicit