Jersey update from 3.1.3 to 3.1.4 slows down our external service res…

…ponse times drastically #5738

Signed-off-by: Jorge Bescos Gascon <jorge.bescos.gascon@oracle.com>

core-client/src/main/java/org/glassfish/jersey/client/HttpUrlConnectorProvider.java

@@ -21,6 +21,7 @@
 import java.net.Proxy;
 import java.net.URL;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.logging.Logger;
 
 import jakarta.ws.rs.client.Client;
@@ -258,7 +259,7 @@ protected Connector createHttpUrlConnector(Client client, ConnectionFactory conn
      * via {@link #connectionFactory(ConnectionFactory)} method.
      */
     public interface ConnectionFactory {
-
+        
         /**
          * Get a {@link java.net.HttpURLConnection} for a given URL.
          * <p>
@@ -295,9 +296,23 @@ default HttpURLConnection getConnection(URL url, Proxy proxy) throws IOException
 
     private static class DefaultConnectionFactory implements ConnectionFactory {
 
+        private final ConcurrentHashMap<URL, Object> locks = new ConcurrentHashMap<>();
+
         @Override
         public HttpURLConnection getConnection(final URL url) throws IOException {
-            return (HttpURLConnection) url.openConnection();
+            return connect(url, null);
+        }
+
+        @Override
+        public HttpURLConnection getConnection(URL url, Proxy proxy) throws IOException {
+            return connect(url, proxy);
+        }
+
+        private HttpURLConnection connect(URL url, Proxy proxy) throws IOException {
+            Object lock = locks.computeIfAbsent(url, u -> new Object());
+            synchronized (lock){
+                return (proxy == null) ? (HttpURLConnection) url.openConnection() : (HttpURLConnection) url.openConnection(proxy);
+            }
         }
     }