@Constantin Stanca
I have come across a certain blog which implements a scala code to generate the Hierarchal data In hive using UDTF.
But I have come acrss this below source code. But not sure How to execute or implement this.
class ExpandTree2UDTF extends GenericUDTF {
var inputOIs: Array[PrimitiveObjectInspector] = null
val tree: collection.mutable.Map[String,Option[String]] = collection.mutable.Map()
override def initialize(args: Array[ObjectInspector]): StructObjectInspector = {
inputOIs = args.map{_.asInstanceOf[PrimitiveObjectInspector]}
val fieldNames = java.util.Arrays.asList("id", "ancestor", "level")
val fieldOI = primitive.PrimitiveObjectInspectorFactory.javaStringObjectInspector.asInstanceOf[ObjectInspector]
val fieldOIs = java.util.Arrays.asList(fieldOI, fieldOI, fieldOI)
ObjectInspectorFactory.getStandardStructObjectInspector(fieldNames, fieldOIs);
}
def process(record: Array[Object]) {
val id = inputOIs(0).getPrimitiveJavaObject(record(0)).asInstanceOf[String]
val parent = Option(inputOIs(1).getPrimitiveJavaObject(record(1)).asInstanceOf[String])
tree += ( id -> parent )
}
def close {
val expandTree = collection.mutable.Map[String,List[String]]()
def calculateAncestors(id: String): List[String] =
tree(id) match { case Some(parent) => id :: getAncestors(parent) ; case None => List(id) }
def getAncestors(id: String) = expandTree.getOrElseUpdate(id, calculateAncestors(id))
tree.keys.foreach{ id => getAncestors(id).zipWithIndex.foreach{ case(ancestor,level) => forward(Array(id, ancestor, level)) } }
}
}
