replace more uses of Util.immutableSeq

actor/src/main/scala/org/apache/pekko/actor/ActorPath.scala

@@ -21,7 +21,7 @@ import scala.collection.immutable
 import scala.annotation.nowarn
 
 import org.apache.pekko
-import pekko.japi.Util.immutableSeq
+import pekko.util.ccompat.JavaConverters._
 
 /**
  * Java API
@@ -206,7 +206,7 @@ sealed trait ActorPath extends Comparable[ActorPath] with Serializable {
   /**
    * Java API: Recursively create a descendant’s path by appending all child names.
    */
-  def descendant(names: java.lang.Iterable[String]): ActorPath = /(immutableSeq(names))
+  def descendant(names: java.lang.Iterable[String]): ActorPath = /(names.asScala)
 
   /**
    * Sequence of names for this path from root to this. Performance implication: has to allocate a list.

actor/src/main/scala/org/apache/pekko/actor/ActorSystem.scala

@@ -43,6 +43,7 @@ import pekko.util._
 import pekko.util.FutureConverters._
 import pekko.util.OptionConverters._
 import pekko.util.Helpers.toRootLowerCase
+import pekko.util.ccompat.JavaConverters._
 
 object BootstrapSetup {
 
@@ -564,7 +565,7 @@ abstract class ActorSystem extends ActorRefFactory with ClassicActorSystemProvid
   /**
    * Java API: Recursively create a descendant’s path by appending all child names.
    */
-  def descendant(names: java.lang.Iterable[String]): ActorPath = /(immutableSeq(names))
+  def descendant(names: java.lang.Iterable[String]): ActorPath = /(names.asScala)
 
   /**
    * Start-up time in milliseconds since the epoch.
@@ -1210,7 +1211,7 @@ private[pekko] class ActorSystemImpl(
      */
     def loadExtensions(key: String, throwOnLoadFail: Boolean): Unit = {
 
-      immutableSeq(settings.config.getStringList(key)).foreach { fqcn =>
+      settings.config.getStringList(key).asScala.foreach { fqcn =>
         dynamicAccess.getObjectFor[AnyRef](fqcn).recoverWith {
           case firstProblem =>
             dynamicAccess.createInstanceFor[AnyRef](fqcn, Nil).recoverWith { case _ => Failure(firstProblem) }

cluster-tools/src/main/scala/org/apache/pekko/cluster/client/ClusterClient.scala

@@ -47,12 +47,12 @@ import pekko.cluster.ClusterEvent._
 import pekko.cluster.Member
 import pekko.cluster.MemberStatus
 import pekko.cluster.pubsub._
-import pekko.japi.Util.immutableSeq
 import pekko.remote.DeadlineFailureDetector
 import pekko.routing.ConsistentHash
 import pekko.routing.MurmurHash
 import pekko.util.MessageBuffer
 import pekko.util.ccompat._
+import pekko.util.ccompat.JavaConverters._
 
 @ccompatUsedUntil213
 @deprecated(
@@ -72,7 +72,7 @@ object ClusterClientSettings {
    * the default configuration `pekko.cluster.client`.
    */
   def apply(config: Config): ClusterClientSettings = {
-    val initialContacts = immutableSeq(config.getStringList("initial-contacts")).map(ActorPath.fromString).toSet
+    val initialContacts = config.getStringList("initial-contacts").asScala.map(ActorPath.fromString).toSet
     new ClusterClientSettings(
       initialContacts,
       establishingGetContactsInterval = config.getDuration("establishing-get-contacts-interval", MILLISECONDS).millis,

cluster/src/main/scala/org/apache/pekko/cluster/ClusterSettings.scala

@@ -23,9 +23,9 @@ import org.apache.pekko
 import pekko.actor.Address
 import pekko.actor.AddressFromURIString
 import pekko.annotation.InternalApi
-import pekko.japi.Util.immutableSeq
 import pekko.util.Helpers.{ toRootLowerCase, ConfigOps, Requiring }
 import pekko.util.Version
+import pekko.util.ccompat.JavaConverters._
 
 object ClusterSettings {
   type DataCenter = String
@@ -87,7 +87,7 @@ final class ClusterSettings(val config: Config, val systemName: String) {
   }
 
   val SeedNodes: immutable.IndexedSeq[Address] =
-    immutableSeq(cc.getStringList("seed-nodes")).map {
+    cc.getStringList("seed-nodes").asScala.map {
       case AddressFromURIString(address) => address
       case _                             => throw new RuntimeException() // compiler exhaustiveness check pleaser
     }.toVector
@@ -161,7 +161,7 @@ final class ClusterSettings(val config: Config, val systemName: String) {
   val SelfDataCenter: DataCenter = cc.getString("multi-data-center.self-data-center")
 
   val Roles: Set[String] = {
-    val configuredRoles = immutableSeq(cc.getStringList("roles")).toSet.requiring(
+    val configuredRoles = cc.getStringList("roles").asScala.toSet.requiring(
       _.forall(!_.startsWith(DcRolePrefix)),
       s"Roles must not start with '$DcRolePrefix' as that is reserved for the cluster self-data-center setting")
 

remote/src/main/scala/org/apache/pekko/remote/RemoteDeployer.scala

@@ -18,10 +18,10 @@ import com.typesafe.config._
 import org.apache.pekko
 import pekko.ConfigurationException
 import pekko.actor._
-import pekko.japi.Util.immutableSeq
 import pekko.remote.routing.RemoteRouterConfig
 import pekko.routing._
 import pekko.routing.Pool
+import pekko.util.ccompat.JavaConverters._
 
 @SerialVersionUID(1L)
 final case class RemoteScope(node: Address) extends Scope {
@@ -41,7 +41,7 @@ private[pekko] class RemoteDeployer(_settings: ActorSystem.Settings, _pm: Dynami
           case AddressFromURIString(r) => Some(deploy.copy(scope = RemoteScope(r)))
           case str if !str.isEmpty     => throw new ConfigurationException(s"unparseable remote node name [$str]")
           case _ =>
-            val nodes = immutableSeq(deploy.config.getStringList("target.nodes")).map(AddressFromURIString(_))
+            val nodes = deploy.config.getStringList("target.nodes").asScala.map(AddressFromURIString(_))
             if (nodes.isEmpty || deploy.routerConfig == NoRouter) d
             else
               deploy.routerConfig match {

remote/src/main/scala/org/apache/pekko/remote/RemoteSettings.scala

@@ -62,7 +62,7 @@ final class RemoteSettings(val config: Config) {
     if (Artery.Enabled) Artery.UntrustedMode else UntrustedMode
   @deprecated("Classic remoting is deprecated, use Artery", "Akka 2.6.0")
   val TrustedSelectionPaths: Set[String] =
-    immutableSeq(getStringList("pekko.remote.classic.trusted-selection-paths")).toSet
+    getStringList("pekko.remote.classic.trusted-selection-paths").asScala.toSet
 
   @deprecated("Classic remoting is deprecated, use Artery", "Akka 2.6.0")
   val RemoteLifecycleEventsLogLevel: LogLevel = toRootLowerCase(
@@ -211,7 +211,7 @@ final class RemoteSettings(val config: Config) {
   }
 
   val AcceptProtocolNames: Set[String] = {
-    val set = immutableSeq(getStringList("pekko.remote.accept-protocol-names")).toSet
+    val set = getStringList("pekko.remote.accept-protocol-names").asScala.toSet
     if (set.isEmpty) {
       throw new ConfigurationException("pekko.remote.accept-protocol-names setting must not be empty. " +
         "The setting is an array and the only acceptable values are \"pekko\" and \"akka\".")

remote/src/main/scala/org/apache/pekko/remote/artery/ArterySettings.scala

@@ -23,7 +23,6 @@ import com.typesafe.config.ConfigFactory
 
 import org.apache.pekko
 import pekko.NotUsed
-import pekko.japi.Util.immutableSeq
 import pekko.stream.ActorMaterializerSettings
 import pekko.util.Helpers.ConfigOps
 import pekko.util.Helpers.Requiring
@@ -79,7 +78,7 @@ private[pekko] final class ArterySettings private (config: Config) {
   val SSLEngineProviderClassName: String = config.getString("ssl.ssl-engine-provider")
 
   val UntrustedMode: Boolean = getBoolean("untrusted-mode")
-  val TrustedSelectionPaths: Set[String] = immutableSeq(getStringList("trusted-selection-paths")).toSet
+  val TrustedSelectionPaths: Set[String] = getStringList("trusted-selection-paths").asScala.toSet
 
   val LogReceive: Boolean = getBoolean("log-received-messages")
   val LogSend: Boolean = getBoolean("log-sent-messages")

remote/src/main/scala/org/apache/pekko/remote/artery/tcp/ssl/SSLEngineConfig.scala

@@ -15,7 +15,7 @@ package org.apache.pekko.remote.artery.tcp.ssl
 
 import org.apache.pekko
 import pekko.annotation.InternalApi
-import pekko.japi.Util.immutableSeq
+import pekko.util.ccompat.JavaConverters._
 import com.typesafe.config.Config
 
 import scala.concurrent.duration.FiniteDuration
@@ -30,7 +30,7 @@ private[tcp] class SSLEngineConfig(config: Config) {
 
   private[tcp] val SSLProtocol: String = config.getString("protocol")
   private[tcp] val SSLEnabledAlgorithms: Set[String] =
-    immutableSeq(config.getStringList("enabled-algorithms")).toSet
+    config.getStringList("enabled-algorithms").asScala.toSet
   private[tcp] val SSLRequireMutualAuthentication: Boolean = {
     if (config.hasPath("require-mutual-authentication"))
       config.getBoolean("require-mutual-authentication")

remote/src/main/scala/org/apache/pekko/remote/routing/RemoteRouterConfig.scala

@@ -26,7 +26,6 @@ import pekko.actor.Address
 import pekko.actor.Deploy
 import pekko.actor.Props
 import pekko.actor.SupervisorStrategy
-import pekko.japi.Util.immutableSeq
 import pekko.remote.RemoteScope
 import pekko.routing.ActorRefRoutee
 import pekko.routing.Pool
@@ -35,6 +34,7 @@ import pekko.routing.Routee
 import pekko.routing.Router
 import pekko.routing.RouterActor
 import pekko.routing.RouterConfig
+import pekko.util.ccompat.JavaConverters._
 
 /**
  * [[pekko.routing.RouterConfig]] implementation for remote deployment on defined
@@ -47,8 +47,8 @@ final case class RemoteRouterConfig(local: Pool, nodes: Iterable[Address]) exten
 
   require(nodes.nonEmpty, "Must specify list of remote target.nodes")
 
-  def this(local: Pool, nodes: java.lang.Iterable[Address]) = this(local, immutableSeq(nodes))
-  def this(local: Pool, nodes: Array[Address]) = this(local, nodes: Iterable[Address])
+  def this(local: Pool, nodes: java.lang.Iterable[Address]) = this(local, nodes.asScala.toSeq)
+  def this(local: Pool, nodes: Array[Address]) = this(local, nodes.toSeq)
 
   // need this iterator as instance variable since Resizer may call createRoutees several times
   @nowarn @transient private val nodeAddressIter: Iterator[Address] = Stream.continually(nodes).flatten.iterator

remote/src/main/scala/org/apache/pekko/remote/transport/netty/NettySSLSupport.scala

@@ -17,8 +17,8 @@ import scala.annotation.nowarn
 
 import com.typesafe.config.Config
 import org.apache.pekko
-import pekko.japi.Util._
-import pekko.util.ccompat._
+import pekko.util.ccompat.ccompatUsedUntil213
+import pekko.util.ccompat.JavaConverters._
 
 import io.netty.channel.Channel
 import io.netty.handler.ssl.SslHandler
@@ -40,7 +40,7 @@ private[pekko] class SSLSettings(config: Config) {
 
   val SSLTrustStorePassword = getString("trust-store-password")
 
-  val SSLEnabledAlgorithms = immutableSeq(getStringList("enabled-algorithms")).to(Set)
+  val SSLEnabledAlgorithms = getStringList("enabled-algorithms").asScala.toSet
 
   val SSLProtocol = getString("protocol")