SystemRoleFactory.java

  1. /*
  2.  * *************************************************************************************************************************************************************
  3.  *
  4.  * TheseFoolishThings: Miscellaneous utilities
  5.  * http://tidalwave.it/projects/thesefoolishthings
  6.  *
  7.  * Copyright (C) 2009 - 2025 by Tidalwave s.a.s. (http://tidalwave.it)
  8.  *
  9.  * *************************************************************************************************************************************************************
  10.  *
  11.  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
  12.  * You may obtain a copy of the License at
  13.  *
  14.  *     http://www.apache.org/licenses/LICENSE-2.0
  15.  *
  16.  * 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
  17.  * CONDITIONS OF ANY KIND, either express or implied.  See the License for the specific language governing permissions and limitations under the License.
  18.  *
  19.  * *************************************************************************************************************************************************************
  20.  *
  21.  * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
  22.  * git clone https://github.com/tidalwave-it/thesefoolishthings-src
  23.  *
  24.  * *************************************************************************************************************************************************************
  25.  */
  26. package it.tidalwave.role.spi;

  27. import javax.annotation.Nonnull;
  28. import java.util.List;
  29. import it.tidalwave.util.LazySupplier;
  30. import static it.tidalwave.role.impl.ServiceLoaderLocator.lazySupplierOf;

  31. /***************************************************************************************************************************************************************
  32.  *
  33.  * A service which retrieves DCI Roles for a given object.
  34.  *
  35.  * @author  Fabrizio Giudici
  36.  *
  37.  **************************************************************************************************************************************************************/
  38. @FunctionalInterface
  39. public interface SystemRoleFactory
  40.   {
  41.     static class Inner
  42.       {
  43.         private static final LazySupplier<SystemRoleFactory> INSTANCE_REF =
  44.                 LazySupplier.of(() -> Inner.PROVIDER_REF.get().getSystemRoleFactory());

  45.         private static final LazySupplier<SystemRoleFactoryProvider> PROVIDER_REF =
  46.                 lazySupplierOf(SystemRoleFactoryProvider.class);
  47.       }

  48.     /***********************************************************************************************************************************************************
  49.      * Returns a singleton instance.
  50.      *
  51.      * @return  the singleton instance
  52.      **********************************************************************************************************************************************************/
  53.     @Nonnull
  54.     public static SystemRoleFactory getInstance()
  55.       {
  56.         return Inner.INSTANCE_REF.get();
  57.       }

  58.     /***********************************************************************************************************************************************************
  59.      * Removes a previously installed {@link SystemRoleFactory}. <b>This method is for testing only (used to clean up a
  60.      * testing context).</b>
  61.      *
  62.      * @see     #set(SystemRoleFactory)
  63.      **********************************************************************************************************************************************************/
  64.     public static void reset()
  65.       {
  66.         Inner.PROVIDER_REF.clear();
  67.         Inner.INSTANCE_REF.clear();
  68.       }

  69.     /***********************************************************************************************************************************************************
  70.      * Installs a {@link SystemRoleFactory}. <b>This method is for testing only (used to set up a testing context).</b>
  71.      *
  72.      * @param   systemRoleFactory   the {@link SystemRoleFactory}
  73.      * @see     #reset()
  74.      **********************************************************************************************************************************************************/
  75.     public static void set (@Nonnull final SystemRoleFactory systemRoleFactory)
  76.       {
  77.         Inner.PROVIDER_REF.set(() -> systemRoleFactory);
  78.       }

  79.     /***********************************************************************************************************************************************************
  80.      * Retrieves the roles of the given class for the given owner object.
  81.      *
  82.      * @param <T>           the static type of the roles
  83.      * @param   owner       the owner object
  84.      * @param   roleType    the dynamic type of the roles
  85.      * @return              a list of roles
  86.      **********************************************************************************************************************************************************/
  87.     @Nonnull
  88.     public <T> List<T> findRoles (@Nonnull Object owner, @Nonnull Class<? extends T> roleType);
  89.   }