Parsing a complex map using recursive function in scala

Question

I hv a json file like below

{

"Item Version": 1.0,
"Action2": "true12",
"Item Creation Time": "2019-04-14 14:15:09",
"Trade Dictionary": {
    "Country": "India",
    "TradeNumber": "1",
    "action": {
        "Action2": true,
        "Action1": false
    },
    "Value": "XXXXXXXXXXXXXXX"
},
"Payments": {
    "abc": "def",
    "Payment Details": [{
        "Payment Date": "2019-04-11",
        "Payment Type": [{
            "Payval": "myval "
        }]
    }]
}

}

I have a scala code like this

def secondFlatten(map: Map[String, Any]):Map[String, Any]={val c=map.flatten {

val c=map.flatten {

 case ((key, map : Map[String, Any])) => {
   map.flatten {
     case ((innerKey: String, l: List[Map[String, Any]])) => l.head.flatten
     {

               case ((key1: String, l1: List[Map[String, Any]]))=>l1.head.map{case (x:String, y: Any)=> (s"$key->$innerKey->$key1->$x"-> y)}
               case ((key1: String, m1 : Map[String, Any])) =>  m1.map{case (x:String, y: Any)=> (s"$key->$innerKey->$key1->$x"-> y)}
               case (key1: String, value1: String) => Map(s"$key->$innerKey->$key1"-> value1)
     }
     case ((innerKey: String, m : Map[String, Any])) => m.map{case (x:String, y: Any)=> (s"$key->$innerKey->$x"-> y)}
     case (innerKey: String, value: String) => Map(s"$key->$innerKey"-> value)
}
}
case ((key, value)) => Map(key -> value)

}.toMap
return c

}

which returns values like this

(Payments->Payment Details->Payment Date,2019-04-11)

(Trade Dictionary->Value,XXXXXXXXXXXXXXX)

(Payments->Payment Details->Payment Type->Payval,myval )

(Trade Dictionary->Country,India)

(Trade Dictionary->TradeNumber,1)

(Trade Dictionary->action->Action1,false)

(Action2,true12)

(Item Version,1.0)

(Trade Dictionary->action->Action2,true)

(Item Creation Time,2019-04-14 14:15:09)

(Payments->abc,def)

Is there any way to write a recursive function instead of putting the same kind of case statement???

ben · Accepted Answer · 2019-11-28 14:49:03Z

0

Here you go:

def flattenMap(m: Map[String, Any], tree: List[String] = List()) : Iterable[(String, Any)] = m.flatten {
  case (k: String, v: Map[String, Any] @unchecked) => flattenMap(v, tree :+ k)
  case (k: String, v: List[Map[String, Any]] @unchecked) => v.flatten(flattenMap(_, tree :+ k))
  case (k: String, v: Any) => List((tree :+ k.toString).mkString("->") -> v)
  case (k: String, null) => List((tree :+ k).mkString("->") -> null)
}

(repl here: https://scastie.scala-lang.org/benrobby/9fWtDyvyTt28BEul6UJ4Bg)

edited Nov 28, 2019 at 14:49

answered Nov 23, 2019 at 14:49

ben

585 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Nilay Over a year ago

this does not work if value is null or any number..Like if the key value pair is "CLS": true, "money":2.378 "userComments": null, for this cases we get match error

ben Over a year ago

just add another case statement, updated my answer.

Collectives™ on Stack Overflow

Parsing a complex map using recursive function in scala

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related