Key.java
- /*
- * *************************************************************************************************************************************************************
- *
- * TheseFoolishThings: Miscellaneous utilities
- * http://tidalwave.it/projects/thesefoolishthings
- *
- * Copyright (C) 2009 - 2024 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 javax.annotation.concurrent.Immutable;
- import java.util.Comparator;
- import java.util.Set;
- import java.util.TreeSet;
- import java.util.concurrent.ConcurrentHashMap;
- import java.io.Serializable;
- import it.tidalwave.util.annotation.VisibleForTesting;
- import lombok.AccessLevel;
- import lombok.EqualsAndHashCode;
- import lombok.Getter;
- import lombok.RequiredArgsConstructor;
- import lombok.ToString;
- /***************************************************************************************************************************************************************
- *
- * @author Fabrizio Giudici
- * @since 1.11.0
- * @stereotype flyweight
- *
- **************************************************************************************************************************************************************/
- @Immutable @RequiredArgsConstructor(access = AccessLevel.PRIVATE) @EqualsAndHashCode @ToString
- public class Key<T> implements StringValue, Comparable<Key<?>>, Serializable
- {
- private static final long serialVersionUID = 2817490298518793579L;
- // FIXME: a Set would be enough.
- @VisibleForTesting static final ConcurrentHashMap<Key<?>, Key<?>> INSTANCES = new ConcurrentHashMap<>();
- @Getter @Nonnull
- private final String name;
- @Getter @Nonnull
- private final Class<T> type;
- /***********************************************************************************************************************************************************
- * Create a new instance with the given name.
- *
- * @param name the name
- * @deprecated use {@link #of(String, Class)}
- **********************************************************************************************************************************************************/
- @Deprecated
- public Key (@Nonnull final String name)
- {
- this.name = name;
- type = (Class<T>)ReflectionUtils.getTypeArguments(Key.class, getClass()).get(0);
- }
- /***********************************************************************************************************************************************************
- * Creates an instance with the given name and type. If an identical key already exists, that existing instance is
- * returned. It is allowed to have two keys with the same name and different types (e.g. {@code Key.of("foo",
- * String.class)} and {@code Key.of("foo", Integer.class)}): they are considered as two distinct keys. This feature
- * allows to treat the same data both as typed and type-agnostic at the same time; for instance, a collection of
- * properties could be read from a configuration file in type-agnostic way (if there is no type information in
- * the file) and later managed as typed only when needed.
- *
- * @param <T> the static type
- * @param name the name
- * @param type the dynamic type
- * @return the key
- * @since 3.2-ALPHA-2
- **********************************************************************************************************************************************************/
- @Nonnull @SuppressWarnings("unchecked")
- public static <T> Key<T> of (@Nonnull final String name, @Nonnull final Class<T> type)
- {
- final var newKey = new Key<T>(name, type);
- final var key = (Key<T>)INSTANCES.putIfAbsent(newKey, newKey);
- return key != null ? key : newKey;
- }
- /***********************************************************************************************************************************************************
- * Creates an instance with the given name. Type is considered as unknown (and assumed as {@link Object}). Please
- * see {@link #of(String, Class)} for more information.
- *
- * @param name the name
- * @return the key
- * @since 3.2-ALPHA-4
- **********************************************************************************************************************************************************/
- @Nonnull
- public static Key<Object> of (@Nonnull final String name)
- {
- return of(name, Object.class);
- }
- /***********************************************************************************************************************************************************
- * Returns all the keys registered in the system.
- *
- * @return a mutable and sorted set of keys.
- * @since 3.2-ALPHA-2
- **********************************************************************************************************************************************************/
- @Nonnull
- public static Set<Key<?>> allKeys()
- {
- return new TreeSet<>(INSTANCES.values());
- }
- /***********************************************************************************************************************************************************
- * Create a new instance with the given name.
- *
- * @param name the name
- * @deprecated use {@link #of(String, Class)}
- **********************************************************************************************************************************************************/
- public Key (@Nonnull final StringValue name)
- {
- this(name.stringValue());
- }
- /***********************************************************************************************************************************************************
- * {@inheritDoc}
- **********************************************************************************************************************************************************/
- @Override @Nonnull
- public String stringValue()
- {
- return name;
- }
- /***********************************************************************************************************************************************************
- * {@inheritDoc}
- **********************************************************************************************************************************************************/
- @Override
- public int compareTo (@Nonnull final Key<?> other)
- {
- final Comparator<Key<?>> byType = Comparator.comparing(k -> k.getType().getName());
- final Comparator<Key<?>> byName = Comparator.comparing(Key::getName);
- return byName.thenComparing(byType).compare(this, other);
- }
- }