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    import java.util.Date;
022    
023    import org.apache.commons.io.FileUtils;
024    
025    /**
026     * Filters files based on a cutoff time, can filter either newer
027     * files or files equal to or older.
028     * <p>
029     * For example, to print all files and directories in the
030     * current directory older than one day:
031     *
032     * <pre>
033     * File dir = new File(".");
034     * // We are interested in files older than one day
035     * long cutoff = System.currentTimeMillis() - (24 * 60 * 60 * 1000);
036     * String[] files = dir.list( new AgeFileFilter(cutoff) );
037     * for ( int i = 0; i &lt; files.length; i++ ) {
038     *     System.out.println(files[i]);
039     * }
040     * </pre>
041     *
042     * @author Rahul Akolkar
043     * @version $Id: AgeFileFilter.java 606381 2007-12-22 02:03:16Z ggregory $
044     * @since Commons IO 1.2
045     */
046    public class AgeFileFilter extends AbstractFileFilter implements Serializable {
047    
048        /** The cutoff time threshold. */
049        private final long cutoff;
050        /** Whether the files accepted will be older or newer. */
051        private final boolean acceptOlder;
052    
053        /**
054         * Constructs a new age file filter for files equal to or older than
055         * a certain cutoff
056         *
057         * @param cutoff  the threshold age of the files
058         */
059        public AgeFileFilter(long cutoff) {
060            this(cutoff, true);
061        }
062    
063        /**
064         * Constructs a new age file filter for files on any one side
065         * of a certain cutoff.
066         *
067         * @param cutoff  the threshold age of the files
068         * @param acceptOlder  if true, older files (at or before the cutoff)
069         * are accepted, else newer ones (after the cutoff).
070         */
071        public AgeFileFilter(long cutoff, boolean acceptOlder) {
072            this.acceptOlder = acceptOlder;
073            this.cutoff = cutoff;
074        }
075    
076        /**
077         * Constructs a new age file filter for files older than (at or before)
078         * a certain cutoff date.
079         *
080         * @param cutoffDate  the threshold age of the files
081         */
082        public AgeFileFilter(Date cutoffDate) {
083            this(cutoffDate, true);
084        }
085    
086        /**
087         * Constructs a new age file filter for files on any one side
088         * of a certain cutoff date.
089         *
090         * @param cutoffDate  the threshold age of the files
091         * @param acceptOlder  if true, older files (at or before the cutoff)
092         * are accepted, else newer ones (after the cutoff).
093         */
094        public AgeFileFilter(Date cutoffDate, boolean acceptOlder) {
095            this(cutoffDate.getTime(), acceptOlder);
096        }
097    
098        /**
099         * Constructs a new age file filter for files older than (at or before)
100         * a certain File (whose last modification time will be used as reference).
101         *
102         * @param cutoffReference  the file whose last modification
103         *        time is usesd as the threshold age of the files
104         */
105        public AgeFileFilter(File cutoffReference) {
106            this(cutoffReference, true);
107        }
108    
109        /**
110         * Constructs a new age file filter for files on any one side
111         * of a certain File (whose last modification time will be used as
112         * reference).
113         *
114         * @param cutoffReference  the file whose last modification
115         *        time is usesd as the threshold age of the files
116         * @param acceptOlder  if true, older files (at or before the cutoff)
117         * are accepted, else newer ones (after the cutoff).
118         */
119        public AgeFileFilter(File cutoffReference, boolean acceptOlder) {
120            this(cutoffReference.lastModified(), acceptOlder);
121        }
122    
123        //-----------------------------------------------------------------------
124        /**
125         * Checks to see if the last modification of the file matches cutoff
126         * favorably.
127         * <p>
128         * If last modification time equals cutoff and newer files are required,
129         * file <b>IS NOT</b> selected.
130         * If last modification time equals cutoff and older files are required,
131         * file <b>IS</b> selected.
132         *
133         * @param file  the File to check
134         * @return true if the filename matches
135         */
136        public boolean accept(File file) {
137            boolean newer = FileUtils.isFileNewer(file, cutoff);
138            return acceptOlder ? !newer : newer;
139        }
140    
141        /**
142         * Provide a String representaion of this file filter.
143         *
144         * @return a String representaion
145         */
146        public String toString() {
147            String condition = acceptOlder ? "<=" : ">";
148            return super.toString() + "(" + condition + cutoff + ")";
149        }
150    }