fix: list found httpclient implementations and output selected one

Fixes #4935

CHANGELOG.md

@@ -35,6 +35,7 @@
 * Fix #4863: default HttpClient retry logic to 100ms interval
 * Fix #4863: default HttpClient retry logic to 10 attempts
 * Fix #4865: (java-generator) performance improvements
+* Fix #4935: improve HTTP client implementation selection messages
 
 #### Dependency Upgrade
 * Fix #4655: Upgrade Fabric8 Kubernetes Model to Kubernetes v1.26.0

kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/utils/HttpClientUtils.java

@@ -22,6 +22,8 @@
 import io.fabric8.kubernetes.client.http.HttpRequest;
 import io.fabric8.kubernetes.client.http.Interceptor;
 import io.fabric8.kubernetes.client.internal.SSLUtils;
+import java.util.ArrayList;
+import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -73,7 +75,6 @@ public void before(BasicBuilder builder, HttpRequest request, RequestTags tags)
   private static final Pattern IPV4_PATTERN = Pattern.compile(
       "(http://|https://)?(?<ipAddressOrSubnet>(([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.){3}([01]?\\d\\d?|2[0-4]\\d|25[0-5])(\\/([1-2]\\d|3[0-2]|\\d))?)(\\D+|$)");
   private static final Pattern INVALID_HOST_PATTERN = Pattern.compile("[^\\da-zA-Z.\\-/:]+");
-  private static final AtomicBoolean MULTIPLE_HTTP_CLIENT_WARNING_LOGGED = new AtomicBoolean();
 
   private HttpClientUtils() {
   }
@@ -145,22 +146,27 @@ public static HttpClient.Factory getHttpClientFactory() {
             "No httpclient implementations found on the context classloader, please ensure your classpath includes an implementation jar");
       }
     }
+    LOGGER.info("Using httpclient {} factory", factory.getClass().getName());
     return factory;
   }
 
   private static HttpClient.Factory getFactory(ServiceLoader<HttpClient.Factory> loader) {
     HttpClient.Factory factory = null;
+    List<String> detectedFactories = new ArrayList<>(7);
     for (HttpClient.Factory possible : loader) {
-      if (factory != null && MULTIPLE_HTTP_CLIENT_WARNING_LOGGED.compareAndSet(false, true)) {
-        LOGGER.warn("There are multiple httpclient implementation in the classpath, "
-            + "choosing the first non-default implementation. "
-            + "You should exclude dependencies that aren't needed or use an explicit association of the HttpClient.Factory.");
-      }
+      detectedFactories.add(possible.getClass().getName());
       if (factory == null || (factory.isDefault() && !possible.isDefault())
           || (!factory.isDefault()) && factory.priority() < possible.priority()) {
         factory = possible;
       }
     }
+
+    if(detectedFactories.size() > 1) {
+      LOGGER.warn("The following httpclient factories were detected on your classpath: {}, "
+        + "choosing the first non-default implementation. "
+        + "You should exclude dependencies that aren't needed or use an explicit association of the HttpClient.Factory.",
+        detectedFactories);
+    }
     return factory;
   }