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

*** 658,667 ****
--- 658,668 ----
          // 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) {
*** 673,683 ****
                  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;
--- 674,683 ----
*** 710,724 ****
          Module getModule() {
              return moduleRef.get();
          }
  
          ServiceLoader<ResourceBundleProvider> getProviders() {
              return providers;
          }
  
          boolean hasProviders() {
!             return providers != null;
          }
  
          boolean callerHasProvider() {
              return callerHasProvider == Boolean.TRUE;
          }
--- 710,728 ----
          Module getModule() {
              return moduleRef.get();
          }
  
          ServiceLoader<ResourceBundleProvider> getProviders() {
+             if (!providersChecked) {
+                 providers = getServiceLoader(getModule(), name);
+                 providersChecked = true;
+             }
              return providers;
          }
  
          boolean hasProviders() {
!             return getProviders() != null;
          }
  
          boolean callerHasProvider() {
              return callerHasProvider == Boolean.TRUE;
          }
*** 787,798 ****
                      clone.loaderRef = new KeyElementReference<>(getLoader(),
                                                                  referenceQueue, clone);
                  }
                  clone.moduleRef = new KeyElementReference<>(getModule(),
                                                              referenceQueue, clone);
!                 // Clear the reference to ResourceBundleProviders
                  clone.providers = null;
                  // Clear the reference to a Throwable
                  clone.cause = null;
                  // Clear callerHasProvider
                  clone.callerHasProvider = null;
                  return clone;
--- 791,803 ----
                      clone.loaderRef = new KeyElementReference<>(getLoader(),
                                                                  referenceQueue, clone);
                  }
                  clone.moduleRef = new KeyElementReference<>(getModule(),
                                                              referenceQueue, clone);
!                 // 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;
*** 1839,1848 ****
--- 1844,1856 ----
          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);
      }