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 * @version $Id: DelegateFileFilter.java 1304052 2012-03-22 20:55:29Z ggregory $
029 * 
030 * @see FileFilterUtils#asFileFilter(FileFilter)
031 * @see FileFilterUtils#asFileFilter(FilenameFilter)
032 */
033public class DelegateFileFilter extends AbstractFileFilter implements Serializable {
034
035    /** The Filename filter */
036    private final FilenameFilter filenameFilter;
037    /** The File filter */
038    private final FileFilter fileFilter;
039
040    /**
041     * Constructs a delegate file filter around an existing FilenameFilter.
042     * 
043     * @param filter  the filter to decorate
044     */
045    public DelegateFileFilter(FilenameFilter filter) {
046        if (filter == null) {
047            throw new IllegalArgumentException("The FilenameFilter must not be null");
048        }
049        this.filenameFilter = filter;
050        this.fileFilter = null;
051    }
052
053    /**
054     * Constructs a delegate file filter around an existing FileFilter.
055     * 
056     * @param filter  the filter to decorate
057     */
058    public DelegateFileFilter(FileFilter filter) {
059        if (filter == null) {
060            throw new IllegalArgumentException("The FileFilter must not be null");
061        }
062        this.fileFilter = filter;
063        this.filenameFilter = null;
064    }
065
066    /**
067     * Checks the filter.
068     * 
069     * @param file  the file to check
070     * @return true if the filter matches
071     */
072    @Override
073    public boolean accept(File file) {
074        if (fileFilter != null) {
075            return fileFilter.accept(file);
076        } else {
077            return super.accept(file);
078        }
079    }
080
081    /**
082     * Checks the filter.
083     * 
084     * @param dir  the directory
085     * @param name  the filename in the directory
086     * @return true if the filter matches
087     */
088    @Override
089    public boolean accept(File dir, String name) {
090        if (filenameFilter != null) {
091            return filenameFilter.accept(dir, name);
092        } else {
093            return super.accept(dir, name);
094        }
095    }
096
097    /**
098     * Provide a String representaion of this file filter.
099     *
100     * @return a String representaion
101     */
102    @Override
103    public String toString() {
104        String delegate = fileFilter != null ? fileFilter.toString() : filenameFilter.toString(); 
105        return super.toString() + "(" + delegate + ")";
106    }
107    
108}