SupplierFinder.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.util.impl.finder;

  27. // import javax.annotation.concurrent.Immutable;
  28. import jakarta.annotation.Nonnull;
  29. import java.util.Collection;
  30. import java.util.List;
  31. import java.util.concurrent.CopyOnWriteArrayList;
  32. import java.util.function.Supplier;
  33. import it.tidalwave.util.spi.SimpleFinderSupport;

  34. /***************************************************************************************************************************************************************
  35.  *
  36.  * A {@link it.tidalwave.util.Finder} which retrieve results from a {@link Supplier}. Don't use directly; use
  37.  * {@link it.tidalwave.util.Finder#ofSupplier(Supplier)} instead.
  38.  *
  39.  * @author  Fabrizio Giudici
  40.  *
  41.  **************************************************************************************************************************************************************/
  42. /* @Immutable */
  43. public class SupplierFinder<T> extends SimpleFinderSupport<T>
  44.   {
  45.     private static final long serialVersionUID = 1344191036948400804L;

  46.     @Nonnull
  47.     private final Supplier<? extends Collection<? extends T>> supplier;

  48.     /***********************************************************************************************************************************************************
  49.      * Creates a new instance given a supplier.
  50.      * @param   supplier    the supplier
  51.      **********************************************************************************************************************************************************/
  52.     public SupplierFinder (@Nonnull final Supplier<? extends Collection<? extends T>> supplier)
  53.       {
  54.         this.supplier = supplier;
  55.       }

  56.     /***********************************************************************************************************************************************************
  57.      * The special Finder copy constructor.
  58.      * @param   other       the finder to copy
  59.      * @param   override    the overriding object
  60.      **********************************************************************************************************************************************************/
  61.     @SuppressWarnings("unchecked")
  62.     public SupplierFinder (@Nonnull final SupplierFinder<T> other, @Nonnull final Object override)
  63.       {
  64.         super(other, override);
  65.         final var source = getSource(SupplierFinder.class, other, override);
  66.         this.supplier = source.supplier;
  67.       }

  68.     /***********************************************************************************************************************************************************
  69.      * {@inheritDoc}
  70.      **********************************************************************************************************************************************************/
  71.     @Override @Nonnull
  72.     protected List<T> computeResults() // FIXME: or computeNeededResults()?
  73.       {
  74.         return new CopyOnWriteArrayList<>(supplier.get());
  75.       }
  76.   }