Create custom accumulator using Scala for Spark 2.x

custom-accumulator-v2.scala

class MyComplex(var x: Int, var y: Int) extends Serializable{
  def reset(): Unit = {
    x = 0
    y = 0
  }
  def add(p:MyComplex): MyComplex = {
    x = x + p.x
    y = y + p.y
    return this
  }
}

import org.apache.spark.util.AccumulatorV2
object ComplexAccumulatorV2 extends AccumulatorV2[MyComplex, MyComplex] {
    private val myc:MyComplex = new MyComplex(0,0)

    def reset(): Unit = {
        myc.reset()
    }

    def add(v: MyComplex): Unit = {
        myc.add(v)
    }
    def value():MyComplex = {
        return myc
    }
    def isZero(): Boolean = {
        return (myc.x == 0 && myc.y == 0)
    }
    def copy():AccumulatorV2[MyComplex, MyComplex] = {
        return ComplexAccumulatorV2
    }
    def merge(other:AccumulatorV2[MyComplex, MyComplex]) = {
        myc.add(other.value)
    }
}
sc.register(ComplexAccumulatorV2, "mycomplexacc")

//using custom accumulator

var ca = ComplexAccumulatorV2

var rdd = sc.parallelize(1 to 10)
var res = rdd.map(x => ca.add(new MyComplex(x,x)))
res.count
ca.value.x
ca.value.y