Type mismatch found: scala function => Unit required: java.util.Consumer

3
votes

I'm getting the following error in Scala 2.11:

Error:(54, 85) type mismatch;
 found   : org.apache.pig.data.Tuple => Unit
 required: java.util.function.Consumer[_ >: org.apache.pig.data.Tuple]
    pigTest.getAlias("productData").forEachRemaining((x: org.apache.pig.data.Tuple) => print(x))

I'm confused because my function is a consumer so I don't know why it's being rejected or how to fix it.

1
javascala

1 Answers

4
votes

Scala 2.11 doesn't have good interoperability with Java 8 functions. The Pig code I'm calling is Java code that expects a Java consumer, so per this post I have to wrap the scala function.

Resulting code:

pigTest.getAlias("productData").forEachRemaining(toJavaConsumer((x: org.apache.pig.data.Tuple) => print(x)))

where:

  def toJavaConsumer[T](consumer: (T) => Unit): Consumer[T] ={
    new Consumer[T] {
      override def accept(t: T): Unit = {
        consumer(t)
      }
    }
  }