SystemRoleFactory.java

  1. /*
  2.  * *********************************************************************************************************************
  3.  *
  4.  * TheseFoolishThings: Miscellaneous utilities
  5.  * http://tidalwave.it/projects/thesefoolishthings
  6.  *
  7.  * Copyright (C) 2009 - 2023 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
  12.  * the License. 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
  17.  * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the
  18.  * specific language governing permissions and limitations under the License.
  19.  *
  20.  * *********************************************************************************************************************
  21.  *
  22.  * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
  23.  * git clone https://github.com/tidalwave-it/thesefoolishthings-src
  24.  *
  25.  * *********************************************************************************************************************
  26.  */
  27. package it.tidalwave.role.spi;

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

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

  46.         private static final LazySupplier<SystemRoleFactoryProvider> PROVIDER_REF =
  47.                 lazySupplierOf(SystemRoleFactoryProvider.class);
  48.       }

  49.     /*******************************************************************************************************************
  50.      *
  51.      ******************************************************************************************************************/
  52.     @Nonnull
  53.     public static SystemRoleFactory getInstance()
  54.       {
  55.         return Inner.INSTANCE_REF.get();
  56.       }

  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.      ******************************************************************************************************************/
  65.     public static void reset()
  66.       {
  67.         Inner.PROVIDER_REF.clear();
  68.         Inner.INSTANCE_REF.clear();
  69.       }

  70.     /*******************************************************************************************************************
  71.      *
  72.      * Installs a {@link SystemRoleFactory}. <b>This method is for testing only (used to set up a testing context).</b>
  73.      *
  74.      * @param   systemRoleFactory   the {@link SystemRoleFactory}
  75.      * @see     #reset()
  76.      *
  77.      ******************************************************************************************************************/
  78.     public static void set (@Nonnull final SystemRoleFactory systemRoleFactory)
  79.       {
  80.         Inner.PROVIDER_REF.set(() -> systemRoleFactory);
  81.       }

  82.     /*******************************************************************************************************************
  83.      *
  84.      * Retrieves the roles of the given class for the given owner object.
  85.      *
  86.      * @param <T>           the static type of the roles
  87.      * @param   owner       the owner object
  88.      * @param   roleType    the dynamic type of the roles
  89.      * @return              a list of roles
  90.      *
  91.      ******************************************************************************************************************/
  92.     @Nonnull
  93.     public <T> List<T> findRoles (@Nonnull Object owner, @Nonnull Class<? extends T> roleType);
  94.   }