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.FileFilter;
021    import java.io.FilenameFilter;
022    import 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     */
033    public 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    }