ConcurrentHashMapWithOptionals.java
- /*
- * *********************************************************************************************************************
- *
- * TheseFoolishThings: Miscellaneous utilities
- * http://tidalwave.it/projects/thesefoolishthings
- *
- * Copyright (C) 2009 - 2023 by Tidalwave s.a.s. (http://tidalwave.it)
- *
- * *********************************************************************************************************************
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * 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 CONDITIONS OF ANY KIND, either express or implied. See the License for the
- * specific language governing permissions and limitations under the License.
- *
- * *********************************************************************************************************************
- *
- * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
- * git clone https://github.com/tidalwave-it/thesefoolishthings-src
- *
- * *********************************************************************************************************************
- */
- package it.tidalwave.util;
- import javax.annotation.Nonnull;
- import java.util.Optional;
- import java.util.concurrent.ConcurrentHashMap;
- /***********************************************************************************************************************
- *
- * A specialisation of {@link ConcurrentHashMap} with {@link Optional} support.
- *
- * @param <K> the type of the key
- * @param <V> the type of the value
- *
- * @since 3.1-ALPHA-2
- * @author Fabrizio Giudici
- *
- **********************************************************************************************************************/
- public class ConcurrentHashMapWithOptionals<K, V> extends ConcurrentHashMap<K, V>
- {
- private static final long serialVersionUID = -1771492882183193296L;
- /*******************************************************************************************************************
- *
- * If the map doesn't contain the given key, put the new pair(key, value), and return the key itself. Otherwise,
- * do nothing and return an empty {@link Optional}. The map manipulation is atomically performed by calling
- * {@link #putIfAbsent(java.lang.Object, java.lang.Object)}.
- *
- * If {@code optionalKey} is empty, do nothing and return nothing.
- *
- * @param optionalKey the key
- * @param value the value
- * @return the new key, or nothing
- *
- ******************************************************************************************************************/
- @Nonnull
- public Optional<K> putIfAbsentAndGetNewKey (@Nonnull final Optional<? extends K> optionalKey, @Nonnull final V value)
- {
- return optionalKey.flatMap(key -> putIfAbsentAndGetNewKey(key, value));
- }
- /*******************************************************************************************************************
- *
- * If the map doesn't contain the given key, put the new pair(key, value), and return the key itself. Otherwise,
- * do nothing and return an empty {@link Optional}. The map manipulation is atomically performed by calling
- * {@link #putIfAbsent(java.lang.Object, java.lang.Object)}.
- *
- * @param key the key
- * @param value the value
- * @return the new key, or nothing
- *
- ******************************************************************************************************************/
- @Nonnull
- public Optional<K> putIfAbsentAndGetNewKey (@Nonnull final K key, @Nonnull final V value)
- {
- return (putIfAbsent(key, value) == null) ? Optional.of(key) : Optional.empty();
- }
- }