Parameters.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.CheckForNull;
- import javax.annotation.Nonnull;
- import java.util.ArrayList;
- import java.util.Collection;
- import java.util.List;
- import lombok.AccessLevel;
- import lombok.RequiredArgsConstructor;
- /***************************************************************************************************************************************************************
- *
- * This class provides a few static utility methods to manipulate arguments to methods.
- *
- * @author Fabrizio Giudici
- * @it.tidalwave.javadoc.stable
- *
- **************************************************************************************************************************************************************/
- @RequiredArgsConstructor(access = AccessLevel.PRIVATE)
- public final class Parameters
- {
- /***********************************************************************************************************************************************************
- * A convenience method for transforming a varargs of objects to a {@link Collection}. It supports concatenating
- * collections: that is, each varargs item that is a {@link Collection} is flattened.
- *
- * @param objects the objects as varargs
- * @return the objects as collection
- * @since 3.2-ALPHA-3
- * @it.tidalwave.javadoc.experimental
- **********************************************************************************************************************************************************/
- @Nonnull
- public static Collection<Object> r (@Nonnull final Object... objects)
- {
- // Don't use streams() for performance reasons.
- final List<Object> result = new ArrayList<>();
- for (final var object : objects)
- {
- if (!(object instanceof Collection))
- {
- result.add(object);
- }
- else
- {
- result.addAll((Collection<?>)object);
- }
- }
- return result;
- }
- /***********************************************************************************************************************************************************
- * Extracts a singled-value parameter of the given type from an array. If the parameter is not found, the default
- * value is returned. If more than a single parameter is found, an {@link IllegalArgumentException} is thrown.
- *
- * @param <T> the static type of the parameter
- * @param parameterClass the dynamic type of the parameter
- * @param defaultOption the default value of the parameter
- * @param parameters the array of parameters
- * @return the value of the parameter
- * @throws IllegalArgumentException if more than a single value is found
- **********************************************************************************************************************************************************/
- @CheckForNull
- public static <T> T find (@Nonnull final Class<? extends T> parameterClass,
- @CheckForNull final T defaultOption,
- @Nonnull final Object... parameters)
- throws IllegalArgumentException
- {
- // Don't use streams() for performance reasons.
- final var c = find(parameterClass, parameters);
- if (c.size() > 1)
- {
- throw new IllegalArgumentException(String.format("Multiple values for %s have been specified",
- parameterClass.getSimpleName()));
- }
- return c.isEmpty() ? defaultOption : c.iterator().next();
- }
- /***********************************************************************************************************************************************************
- * Extracts multiple-value parameters of the given type from an array. If the parameter is not found, an empty
- * collection is returned.
- *
- * @param <T> the static type of the parameter
- * @param parameterClass the class of the parameter to retrieve
- * @param parameters the array of parameters
- * @return the value of the parameter
- **********************************************************************************************************************************************************/
- @Nonnull
- public static <T> Collection<T> find (@Nonnull final Class<? extends T> parameterClass,
- @Nonnull final Object... parameters)
- {
- // Don't use streams() for performance reasons.
- final Collection<T> result = new ArrayList<>();
- for (final var parameter : parameters)
- {
- if (parameterClass.isAssignableFrom(parameter.getClass()))
- {
- result.add(parameterClass.cast(parameter));
- }
- }
- return result;
- }
- /***********************************************************************************************************************************************************
- * <b>This method is for internal implementation only.</b> Ensures that a given object is neither an array nor a
- * collection.
- *
- * @param object the object to check
- * @param message the message to put in the exception
- * @return the object itself for calling this method as a function
- **********************************************************************************************************************************************************/
- @Nonnull
- public static Object mustNotBeArrayOrCollection (@Nonnull final Object object, @Nonnull final String message)
- {
- if (object instanceof Collection)
- {
- throw new IllegalArgumentException(message + " can't be a Collection");
- }
- if (object.getClass().isArray())
- {
- throw new IllegalArgumentException(message + " can't be an array");
- }
- return object;
- }
- }