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.vfs2.filter;
018
019import java.io.Serializable;
020
021import org.apache.commons.vfs2.FileFilter;
022import org.apache.commons.vfs2.FileSelectInfo;
023import org.apache.commons.vfs2.FileSystemException;
024
025/**
026 * This filter produces a logical NOT of the filters specified.
027 *
028 * @author This code was originally ported from Apache Commons IO File Filter
029 * @see "https://commons.apache.org/proper/commons-io/"
030 * @since 2.4
031 */
032public class NotFileFilter implements FileFilter, Serializable {
033
034    private static final long serialVersionUID = 1L;
035
036    /** The filter. */
037    private final FileFilter filter;
038
039    /**
040     * Constructs a new file filter that NOTs the result of another filter.
041     *
042     * @param filter the filter, must not be null
043     */
044    public NotFileFilter(final FileFilter filter) {
045        if (filter == null) {
046            throw new IllegalArgumentException("The filter must not be null");
047        }
048        this.filter = filter;
049    }
050
051    /**
052     * Returns the logical NOT of the underlying filter's return value for the same
053     * File.
054     *
055     * @param fileSelectInfo the File to check
056     * @return {@code true} if the filter returns {@code false}
057     * @throws FileSystemException Thrown for file system errors.
058     */
059    @Override
060    public boolean accept(final FileSelectInfo fileSelectInfo) throws FileSystemException {
061        return !filter.accept(fileSelectInfo);
062    }
063
064    /**
065     * Provide a String representation of this file filter.
066     *
067     * @return a String representation
068     */
069    @Override
070    public String toString() {
071        return super.toString() + "(" + filter + ")";
072    }
073
074}