    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 returns true if the input is an instanceof
    025 * the type stored in this predicate.
    026 *
    027 * @since 3.0
    028 */
    029public final class InstanceofPredicate implements Predicate<Object>, Serializable {
    030
    031    /** Serial version UID */
    032    private static final long serialVersionUID = -6682656911025165584L;
    033
    034    /** The type to compare to */
    035    private final Class<?> iType;
    036
    037    /**
    038     * Factory to create the identity predicate.
    039     *
    040     * @param type  the type to check for, may not be null
    041     * @return the predicate
    042     * @throws NullPointerException if the class is null
    043     */
    044    public static Predicate<Object> instanceOfPredicate(final Class<?> type) {
    045        if (type == null) {
    046            throw new NullPointerException("The type to check instanceof must not be null");
    047        }
    048        return new InstanceofPredicate(type);
    049    }
    050
    051    /**
    052     * Constructor that performs no validation.
    053     * Use <code>instanceOfPredicate</code> if you want that.
    054     *
    055     * @param type  the type to check for
    056     */
    057    public InstanceofPredicate(final Class<?> type) {
    058        super();
    059        iType = type;
    060    }
    061
    062    /**
    063     * Evaluates the predicate returning true if the input object is of the correct type.
    064     *
    065     * @param object  the input object
    066     * @return true if input is of stored type
    067     */
    068    @Override
    069    public boolean evaluate(final Object object) {
    070        return iType.isInstance(object);
    071    }
    072
    073    /**
    074     * Gets the type to compare to.
    075     *
    076     * @return the type
    077     * @since 3.1
    078     */
    079    public Class<?> getType() {
    080        return iType;
    081    }
    082
    083}