src/java.base/share/classes/java/util/ResourceBundle.java

@@ -658,10 +658,11 @@
         // of this instance.
         private int hashCodeCache;
 
         // ResourceBundleProviders for loading ResourceBundles
         private ServiceLoader<ResourceBundleProvider> providers;
+        private boolean providersChecked;
 
         // Boolean.TRUE if the factory method caller provides a ResourceBundleProvier.
         private Boolean callerHasProvider;
 
         CacheKey(String baseName, Locale locale, ClassLoader loader, Module module) {

@@ -673,11 +674,10 @@
                 this.loaderRef = null;
             } else {
                 this.loaderRef = new KeyElementReference<>(loader, referenceQueue, this);
             }
             this.moduleRef = new KeyElementReference<>(module, referenceQueue, this);
-            this.providers = getServiceLoader(module, baseName);
             calculateHashCode();
         }
 
         String getName() {
             return name;

@@ -710,15 +710,19 @@
         Module getModule() {
             return moduleRef.get();
         }
 
         ServiceLoader<ResourceBundleProvider> getProviders() {
+            if (!providersChecked) {
+                providers = getServiceLoader(getModule(), name);
+                providersChecked = true;
+            }
             return providers;
         }
 
         boolean hasProviders() {
-            return providers != null;
+            return getProviders() != null;
         }
 
         boolean callerHasProvider() {
             return callerHasProvider == Boolean.TRUE;
         }

@@ -787,12 +791,13 @@
                     clone.loaderRef = new KeyElementReference<>(getLoader(),
                                                                 referenceQueue, clone);
                 }
                 clone.moduleRef = new KeyElementReference<>(getModule(),
                                                             referenceQueue, clone);
-                // Clear the reference to ResourceBundleProviders
+                // Clear the reference to ResourceBundleProviders and the flag
                 clone.providers = null;
+                clone.providersChecked = false;
                 // Clear the reference to a Throwable
                 clone.cause = null;
                 // Clear callerHasProvider
                 clone.callerHasProvider = null;
                 return clone;

@@ -1839,10 +1844,13 @@
         return bundle;
     }
 
     private static ServiceLoader<ResourceBundleProvider> getServiceLoader(Module module,
                                                                           String baseName) {
+        if (!module.isNamed()) {
+            return null;
+        }
         PrivilegedAction<ClassLoader> pa = module::getClassLoader;
         ClassLoader loader = AccessController.doPrivileged(pa);
         return getServiceLoader(module, loader, baseName);
     }