Introduce AddressSelector interface

Used to be Function<List<Address>,Address>. Having a dedicated
interface can make changes and evolution easier.

Author: acogoluegnes

src/main/java/com/rabbitmq/client/amqp/AddressSelector.java

@@ -0,0 +1,25 @@
+// Copyright (c) 2024 Broadcom. All Rights Reserved.
+// The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// If you have any questions regarding licensing, please contact us at
+// [email protected].
+package com.rabbitmq.client.amqp;
+
+import java.util.List;
+
+public interface AddressSelector {
+
+  Address select(List<Address> addresses);
+}

src/main/java/com/rabbitmq/client/amqp/ConnectionSettings.java

@@ -18,8 +18,6 @@
 package com.rabbitmq.client.amqp;
 
 import java.time.Duration;
-import java.util.List;
-import java.util.function.Function;
 import javax.net.ssl.SSLContext;
 
 public interface ConnectionSettings<T> {
@@ -45,7 +43,7 @@ public interface ConnectionSettings<T> {
 
   T idleTimeout(Duration idleTimeout);
 
-  T addressSelector(Function<List<Address>, Address> selector);
+  T addressSelector(AddressSelector selector);
 
   T saslMechanism(String mechanism);
 

src/main/java/com/rabbitmq/client/amqp/impl/AmqpConnectionBuilder.java

@@ -21,7 +21,6 @@
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.function.Function;
 
 class AmqpConnectionBuilder implements ConnectionBuilder {
 
@@ -86,7 +85,7 @@ public ConnectionBuilder idleTimeout(Duration idleTimeout) {
   }
 
   @Override
-  public ConnectionBuilder addressSelector(Function<List<Address>, Address> selector) {
+  public ConnectionBuilder addressSelector(AddressSelector selector) {
     return this.connectionSettings.addressSelector(selector);
   }
 

src/main/java/com/rabbitmq/client/amqp/impl/DefaultConnectionSettings.java

@@ -32,7 +32,6 @@
 import java.util.List;
 import java.util.Random;
 import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.function.Function;
 import javax.net.ssl.SSLContext;
 import javax.net.ssl.TrustManager;
 import org.apache.qpid.protonj2.client.ConnectionOptions;
@@ -58,7 +57,7 @@ abstract class DefaultConnectionSettings<T> implements ConnectionSettings<T> {
   private List<URI> uris = Collections.emptyList();
   private Duration idleTimeout = Duration.ofMillis(ConnectionOptions.DEFAULT_IDLE_TIMEOUT);
   private static final Random RANDOM = new Random();
-  private Function<List<Address>, Address> addressSelector =
+  private AddressSelector addressSelector =
       addresses -> {
         if (addresses.isEmpty()) {
           throw new IllegalStateException("There should at least one node to connect to");
@@ -150,7 +149,7 @@ public T idleTimeout(Duration idleTimeout) {
   }
 
   @Override
-  public T addressSelector(Function<List<Address>, Address> selector) {
+  public T addressSelector(AddressSelector selector) {
     this.addressSelector = selector;
     return this.toReturn();
   }
@@ -180,7 +179,7 @@ Duration idleTimeout() {
   }
 
   Address selectAddress() {
-    return this.addressSelector.apply(this.addresses);
+    return this.addressSelector.select(this.addresses);
   }
 
   String saslMechanism() {