[SCALA-729] - Convert Java List to Scala Seq (#1361)

* [SCALA-729] - Convert Java List to Scala Seq

* Adding more code examples

* Updated unit test name

* Moved ConvertJavaAListToScalaSeq to new module

* Removed ConvertJavaAListToScalaSeq in old module

---------

Co-authored-by: Callum Gibbons <[email protected]>

Author: cawpat

scala-core-collections-modules/scala-core-collections-4/src/main/scala/com/baeldung/scala/javatoscalaseq/ConvertJavaAListToScalaSeq.scala

@@ -0,0 +1,45 @@
+package com.baeldung.scala.javatoscalaseq
+
+import java.util
+import scala.jdk.javaapi.CollectionConverters
+import scala.collection.JavaConverters
+
+object ConvertJavaAListToScalaSeq {
+
+  private def takeSeq(seq: Seq[String]): String = {
+    seq.mkString
+  }
+
+  def in212(list: util.List[String]): String = {
+    val scalaSeq: Seq[String] =
+      JavaConverters.collectionAsScalaIterable(list).toSeq
+    takeSeq(scalaSeq)
+  }
+
+  def in213(list: util.List[String]): String = {
+    val scalaSeq: Seq[String] = CollectionConverters.asScala(list).toSeq
+    takeSeq(scalaSeq)
+  }
+
+  def convertToList212(list: util.List[String]): String = {
+    val scalaList: List[String] =
+      JavaConverters.collectionAsScalaIterable(list).toList
+    val scalaSet: Set[String] =
+      JavaConverters.collectionAsScalaIterable(list).toSet
+    val scalaIndexedSeq: IndexedSeq[String] =
+      JavaConverters.collectionAsScalaIterable(list).toIndexedSeq
+    val scalaVector: Vector[String] =
+      JavaConverters.collectionAsScalaIterable(list).toVector
+    takeSeq(scalaList)
+  }
+
+  def convertToList213(list: util.List[String]): String = {
+    val scalaList: List[String] = CollectionConverters.asScala(list).toList
+    val scalaSet: Set[String] = CollectionConverters.asScala(list).toSet
+    val scalaIndexedSeq: IndexedSeq[String] =
+      CollectionConverters.asScala(list).toIndexedSeq
+    val scalaVector: Vector[String] =
+      CollectionConverters.asScala(list).toVector
+    takeSeq(scalaList)
+  }
+}

scala-core-collections-modules/scala-core-collections-4/src/test/scala/com/baeldung/scala/javatoscalaseq/ConvertJavaAListToScalaSeqUnitTest.scala

@@ -0,0 +1,27 @@
+package com.baeldung.scala.javatoscalaseq
+
+import java.util
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+class ConvertJavaAListToScalaSeqUnitTest extends AnyFlatSpec with Matchers {
+  val list: util.List[String] = util.ArrayList[String]()
+  list.add("hello")
+  list.add(" world")
+
+  "212" should "return String" in {
+    ConvertJavaAListToScalaSeq.in212(list) shouldBe "hello world"
+  }
+
+  "213" should "return String" in {
+    ConvertJavaAListToScalaSeq.in213(list) shouldBe "hello world"
+  }
+
+  "convertToList212" should "return String" in {
+    ConvertJavaAListToScalaSeq.convertToList212(list) shouldBe "hello world"
+  }
+
+  "convertToList213" should "return String" in {
+    ConvertJavaAListToScalaSeq.convertToList213(list) shouldBe "hello world"
+  }
+}