    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.io.filefilter;
    018
    019import java.io.File;
    020import java.io.FileFilter;
    021import java.io.FilenameFilter;
    022import java.io.Serializable;
    023
    024/**
    025 * This class turns a Java FileFilter or FilenameFilter into an IO FileFilter.
    026 *
    027 * @since 1.0
    028 * @see FileFilterUtils#asFileFilter(FileFilter)
    029 * @see FileFilterUtils#asFileFilter(FilenameFilter)
    030 */
    031public class DelegateFileFilter extends AbstractFileFilter implements Serializable {
    032
    033    private static final long serialVersionUID = -8723373124984771318L;
    034    /** The File filter */
    035    private final FileFilter fileFilter;
    036    /** The Filename filter */
    037    private final FilenameFilter filenameFilter;
    038
    039    /**
    040     * Constructs a delegate file filter around an existing FileFilter.
    041     *
    042     * @param filter  the filter to decorate
    043     */
    044    public DelegateFileFilter(final FileFilter filter) {
    045        if (filter == null) {
    046            throw new IllegalArgumentException("The FileFilter must not be null");
    047        }
    048        this.fileFilter = filter;
    049        this.filenameFilter = null;
    050    }
    051
    052    /**
    053     * Constructs a delegate file filter around an existing FilenameFilter.
    054     *
    055     * @param filter  the filter to decorate
    056     */
    057    public DelegateFileFilter(final FilenameFilter filter) {
    058        if (filter == null) {
    059            throw new IllegalArgumentException("The FilenameFilter must not be null");
    060        }
    061        this.filenameFilter = filter;
    062        this.fileFilter = null;
    063    }
    064
    065    /**
    066     * Checks the filter.
    067     *
    068     * @param file  the file to check
    069     * @return true if the filter matches
    070     */
    071    @Override
    072    public boolean accept(final File file) {
    073        if (fileFilter != null) {
    074            return fileFilter.accept(file);
    075        }
    076        return super.accept(file);
    077    }
    078
    079    /**
    080     * Checks the filter.
    081     *
    082     * @param dir  the directory
    083     * @param name  the file name in the directory
    084     * @return true if the filter matches
    085     */
    086    @Override
    087    public boolean accept(final File dir, final String name) {
    088        if (filenameFilter != null) {
    089            return filenameFilter.accept(dir, name);
    090        }
    091        return super.accept(dir, name);
    092    }
    093
    094    /**
    095     * Provide a String representation of this file filter.
    096     *
    097     * @return a String representation
    098     */
    099    @Override
    100    public String toString() {
    101        final String delegate = fileFilter != null ? fileFilter.toString() : filenameFilter.toString();
    102        return super.toString() + "(" + delegate + ")";
    103    }
    104
    105}