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 *      http://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 */
017package org.apache.commons.collections4.functors;
018
019import java.io.Serializable;
020
021import org.apache.commons.collections4.Predicate;
022
023/**
024 * Predicate implementation that always returns false.
025 *
026 * @since 3.0
027 */
028public final class FalsePredicate<T> implements Predicate<T>, Serializable {
029
030    /** Serial version UID */
031    private static final long serialVersionUID = 7533784454832764388L;
032
033    /** Singleton predicate instance */
034    @SuppressWarnings("rawtypes") // the static instance works for all types
035    public static final Predicate INSTANCE = new FalsePredicate<>();
036
037    /**
038     * Get a typed instance.
039     *
040     * @param <T> the type that the predicate queries
041     * @return the singleton instance
042     * @since 4.0
043     */
044    @SuppressWarnings("unchecked") // the static instance works for all types
045    public static <T> Predicate<T> falsePredicate() {
046        return INSTANCE;
047    }
048
049    /**
050     * Restricted constructor.
051     */
052    private FalsePredicate() {
053        super();
054    }
055
056    /**
057     * Evaluates the predicate returning false always.
058     *
059     * @param object  the input object
060     * @return false always
061     */
062    @Override
063    public boolean evaluate(final T object) {
064        return false;
065    }
066
067    private Object readResolve() {
068        return INSTANCE;
069    }
070
071}