How do I sum up multiple fields of a class?-CodePudding

I have a class Dimensions(Int, Int, Int) and a Shape(String name), put into a Tuple(Shape, Dimensions)

My dataset is:

(Cube, Dimensions(5,5,5))
(Sphere, Dimensions(5,10,15))
(Cube, Dimensions(3,3,3))

I need to return this:

(Cube, Dimensions(8,8,8))
(Sphere, Dimensions(5,10,15))

where I group by the name of the shape then sum up all of the dimension values. Currently I am able to map into a (Name, Int, Int, Int) but I am unsure of how to wrap it back to a Dimension object.

data.map(_._2.map(x => (x.length,x.width,x.height)))

Any help would be appreciated

CodePudding user response：

Assuming there are no very specific special cases and you have a RDD. You just need an aggregateByKey.

case class Dimensions(i1: Int, i2: Int, i3: Int)

val initialRdd: RDD[(Shape, Dimensions)] = ???

def combineDimensions(dimensions1: Dimensions, dimensions2: Dimensions): Dimensions =
  Dimensions(
    dimensions1.i1   dimensions2.i1,
    dimensions1.i2   dimensions2.i2,
    dimensions1.i3   dimensions2.i3
  )

val finalRdd: RDD[(Shape, Dimensions)] =
  initialRdd
    .aggregateByKey(Dimensions(0, 0, 0))(
      { case (accDimensions, dimensions) =>
        combineDimensions(accDimensions, dimensions)
      },
      { case (partitionDimensions1, partitionDimensions2) =>
        combineDimensions(partitionDimensions1, partitionDimensions1)
      }
    )