CODEWITHSUNDEEP
scalascala-collectionsscala-java-interop
toughtalker
toughtalker

Reputation: 471

how to convert List[java.util.Map] to List[Map]

how to convert List[java.util.Map] to List[Map] in scala?

oldList: 

List[java.util.Map[String,String]]

wantedList: 

List[Map[String,String]]

should i new a List[Map] and loop the oldList ?

thanks!

Upvotes: 1

Views: 1051

Answers (3)

4lex1v
4lex1v

Reputation: 21567

JavaConverters were deprecated since Scala 2.9.0 and removed in Scala 2.11-M1 you should not use them. Instead there is a package scala.collection.convert with a module WrapAsScala. It has an implicit convertion dictionaryAsScalaMap

Upvotes: 0

Pooya
Pooya

Reputation: 4481

Use converter methods in Scala collection package. and this is a sample to demonstrate how to convert: 

import scala.collection.JavaConverters._

oldList: List[java.util.Map[String,String]]

wantedList= oldList.asScala

Edited:

as Vladimir Matveev mentioned 

wantedList=oldList.map(_.asScala)

Upvotes: 2

Mikhail Aksenov
Mikhail Aksenov

Reputation: 571

You could use scala.collection.JavaConversions static methods. This one adds implicit conversions from standard Java collections and allows you to perform things like this (let's assume we have already opened REPL and imported scala.collection.JavaConversions._):

scala > x
res1: java.util.HashMap[String,String] = {1=2}

scala> x.toMap
res2: scala.collection.immutable.Map[String,String] = Map(1 -> 2)

You could solve your particular problem as following:

res5: list: List[java.util.HashMap[String, String]] = ()
scala > list.map(e => e.toMap)
res6: List[scala.collection.immutable.Map[String,String]] = ()

Upvotes: 0

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