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     */
017    package org.apache.commons.io.filefilter;
018    
019    import java.io.File;
020    import java.io.Serializable;
021    
022    /**
023     * This filter produces a logical NOT of the filters specified.
024     *
025     * @since 1.0
026     * @version $Id: NotFileFilter.java 1304052 2012-03-22 20:55:29Z ggregory $
027     * @see FileFilterUtils#notFileFilter(IOFileFilter)
028     */
029    public class NotFileFilter extends AbstractFileFilter implements Serializable {
030        
031        /** The filter */
032        private final IOFileFilter filter;
033    
034        /**
035         * Constructs a new file filter that NOTs the result of another filter.
036         * 
037         * @param filter  the filter, must not be null
038         * @throws IllegalArgumentException if the filter is null
039         */
040        public NotFileFilter(IOFileFilter filter) {
041            if (filter == null) {
042                throw new IllegalArgumentException("The filter must not be null");
043            }
044            this.filter = filter;
045        }
046    
047        /**
048         * Returns the logical NOT of the underlying filter's return value for the same File.
049         * 
050         * @param file  the File to check
051         * @return true if the filter returns false
052         */
053        @Override
054        public boolean accept(File file) {
055            return ! filter.accept(file);
056        }
057        
058        /**
059         * Returns the logical NOT of the underlying filter's return value for the same arguments.
060         * 
061         * @param file  the File directory
062         * @param name  the filename
063         * @return true if the filter returns false
064         */
065        @Override
066        public boolean accept(File file, String name) {
067            return ! filter.accept(file, name);
068        }
069    
070        /**
071         * Provide a String representaion of this file filter.
072         *
073         * @return a String representaion
074         */
075        @Override
076        public String toString() {
077            return super.toString() + "(" + filter.toString()  + ")";
078        }
079        
080    }