KAFKA-18854 remove DynamicConfig inner class (apache#19487)

This PR is a umbrella of [KAFKA-18854.
](https://issues.apache.org/jira/browse/KAFKA-18854)

The previous PR encountered some compatibility issues, so we decided to
split it and proceed with the migration step by step.

see apache#19019

Reviewers: PoAn Yang <payang@apache.org>, Chia-Ping Tsai
 <chia7712@gmail.com>

Author: gongxuanzhang

core/src/main/scala/kafka/admin/ConfigCommand.scala

@@ -17,9 +17,6 @@
 
 package kafka.admin
 
-import java.nio.charset.StandardCharsets
-import java.util.concurrent.{ExecutionException, TimeUnit}
-import java.util.{Collections, Properties}
 import joptsimple._
 import kafka.server.DynamicConfig
 import kafka.utils.Implicits._
@@ -32,13 +29,18 @@ import org.apache.kafka.common.protocol.ApiKeys
 import org.apache.kafka.common.quota.{ClientQuotaAlteration, ClientQuotaEntity, ClientQuotaFilter, ClientQuotaFilterComponent}
 import org.apache.kafka.common.security.scram.internals.ScramMechanism
 import org.apache.kafka.common.utils.{Exit, Utils}
+import org.apache.kafka.coordinator.group.GroupConfig
 import org.apache.kafka.server.config.{ConfigType, QuotaConfig}
+import org.apache.kafka.server.metrics.ClientMetricsConfigs
 import org.apache.kafka.server.util.{CommandDefaultOptions, CommandLineUtils}
 import org.apache.kafka.storage.internals.log.LogConfig
 
 import java.net.{InetAddress, UnknownHostException}
-import scala.jdk.CollectionConverters._
+import java.nio.charset.StandardCharsets
+import java.util.concurrent.{ExecutionException, TimeUnit}
+import java.util.{Collections, Properties}
 import scala.collection._
+import scala.jdk.CollectionConverters._
 
 /**
  * This script can be used to change configs for topics/clients/users/brokers/ips/client-metrics/groups dynamically
@@ -250,7 +252,7 @@ object ConfigCommand extends Logging {
         }
 
       case IpType =>
-        val unknownConfigs = (configsToBeAdded.keys ++ configsToBeDeleted).filterNot(key => DynamicConfig.Ip.names.contains(key))
+        val unknownConfigs = (configsToBeAdded.keys ++ configsToBeDeleted).filterNot(key => QuotaConfig.ipConfigs.names.contains(key))
         if (unknownConfigs.nonEmpty)
           throw new IllegalArgumentException(s"Only connection quota configs can be added for '$IpType' using --bootstrap-server. Unexpected config names: ${unknownConfigs.mkString(",")}")
         alterQuotaConfigs(adminClient, entityTypes, entityNames, configsToBeAddedMap, configsToBeDeleted)
@@ -529,11 +531,11 @@ object ConfigCommand extends Logging {
     val addConfig: OptionSpec[String] = parser.accepts("add-config", "Key Value pairs of configs to add. Square brackets can be used to group values which contain commas: 'k1=v1,k2=[v1,v2,v2],k3=v3'. The following is a list of valid configurations: " +
       "For entity-type '" + TopicType + "': " + LogConfig.configNames.asScala.map("\t" + _).mkString(nl, nl, nl) +
       "For entity-type '" + BrokerType + "': " + DynamicConfig.Broker.names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
-      "For entity-type '" + UserType + "': " + DynamicConfig.User.names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
-      "For entity-type '" + ClientType + "': " + DynamicConfig.Client.names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
-      "For entity-type '" + IpType + "': " + DynamicConfig.Ip.names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
-      "For entity-type '" + ClientMetricsType + "': " + DynamicConfig.ClientMetrics.names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
-      "For entity-type '" + GroupType + "': " + DynamicConfig.Group.names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
+      "For entity-type '" + UserType + "': " + QuotaConfig.scramMechanismsPlusUserAndClientQuotaConfigs().names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
+      "For entity-type '" + ClientType + "': " + QuotaConfig.userAndClientQuotaConfigs().names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
+      "For entity-type '" + IpType + "': " + QuotaConfig.ipConfigs.names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
+      "For entity-type '" + ClientMetricsType + "': " + ClientMetricsConfigs.configDef().names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
+      "For entity-type '" + GroupType + "': " + GroupConfig.configDef().names.asScala.toSeq.sorted.map("\t" + _).mkString(nl, nl, nl) +
       s"Entity types '$UserType' and '$ClientType' may be specified together to update config for clients of a specific user.")
       .withRequiredArg
       .ofType(classOf[String])

core/src/main/scala/kafka/server/DynamicConfig.scala

@@ -21,7 +21,6 @@ import kafka.server.DynamicBrokerConfig.AllDynamicConfigs
 
 import java.util.Properties
 import org.apache.kafka.common.config.ConfigDef
-import org.apache.kafka.coordinator.group.GroupConfig
 import org.apache.kafka.server.config.QuotaConfig 
 
 import java.util
@@ -54,47 +53,6 @@ object DynamicConfig {
     def validate(props: Properties): util.Map[String, AnyRef] = DynamicConfig.validate(brokerConfigs, props, customPropsAllowed = true)
   }
 
-  object Client {
-    private val clientConfigs = QuotaConfig.userAndClientQuotaConfigs()
-
-    def configKeys: util.Map[String, ConfigDef.ConfigKey] = clientConfigs.configKeys
-
-    def names: util.Set[String] = clientConfigs.names
-
-    def validate(props: Properties): util.Map[String, AnyRef] = DynamicConfig.validate(clientConfigs, props, customPropsAllowed = false)
-  }
-
-  object User {
-    private val userConfigs = QuotaConfig.scramMechanismsPlusUserAndClientQuotaConfigs()
-
-    def configKeys: util.Map[String, ConfigDef.ConfigKey] = userConfigs.configKeys
-
-    def names: util.Set[String] = userConfigs.names
-
-    def validate(props: Properties): util.Map[String, AnyRef] = DynamicConfig.validate(userConfigs, props, customPropsAllowed = false)
-  }
-
-  object Ip {
-    private val ipConfigs = QuotaConfig.ipConfigs
-
-    def configKeys: util.Map[String, ConfigDef.ConfigKey] = ipConfigs.configKeys
-
-    def names: util.Set[String] = ipConfigs.names
-
-    def validate(props: Properties): util.Map[String, AnyRef] = DynamicConfig.validate(ipConfigs, props, customPropsAllowed = false)
-  }
-
-  object ClientMetrics {
-    private val clientConfigs = org.apache.kafka.server.metrics.ClientMetricsConfigs.configDef()
-
-    def names: util.Set[String] = clientConfigs.names
-  }
-
-  object Group {
-    private val groupConfigs = GroupConfig.configDef()
-
-    def names: util.Set[String] = groupConfigs.names
-  }
 
   private def validate(configDef: ConfigDef, props: Properties, customPropsAllowed: Boolean) = {
     // Validate Names