001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.lang3.function;
019
020import java.util.function.Consumer;
021import java.util.function.Function;
022
023/**
024 * Provides {@link Consumer} instances.
025 *
026 * @since 3.13.0
027 */
028public class Consumers {
029
030    /** NOP singleton. */
031    @SuppressWarnings("rawtypes")
032    private static final Consumer NOP = Function.identity()::apply;
033
034    /**
035     * Applies the given {@link Consumer} action to the object if the consumer is not {@code null}. Otherwise, does nothing.
036     *
037     * @param consumer the consumer to consume.
038     * @param object   the object to be consumed.
039     * @param <T>      the type of the argument the consumer accepts.
040     * @since 3.15.0
041     */
042    public static <T> void accept(final Consumer<T> consumer, final T object) {
043        if (consumer != null) {
044            consumer.accept(object);
045        }
046    }
047
048    /**
049     * Gets the NOP Consumer singleton.
050     *
051     * @param <T> type type to consume.
052     * @return the NOP Consumer singleton.
053     */
054    @SuppressWarnings("unchecked")
055    public static <T> Consumer<T> nop() {
056        return NOP;
057    }
058
059    private Consumers() {
060        // No instances.
061    }
062}