1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.io.comparator; 18 19 import java.io.File; 20 import java.io.Serializable; 21 import java.util.Comparator; 22 23 /** 24 * Compares two files using the <b>default</b> {@link File#compareTo(File)} method. 25 * <p> 26 * This comparator can be used to sort lists or arrays of files 27 * by using the default file comparison. 28 * </p> 29 * <p> 30 * Example of sorting a list of files using the 31 * {@link #DEFAULT_COMPARATOR} singleton instance: 32 * </p> 33 * <pre> 34 * List<File> list = ... 35 * ((AbstractFileComparator) DefaultFileComparator.DEFAULT_COMPARATOR).sort(list); 36 * </pre> 37 * <p> 38 * Example of doing a <i>reverse</i> sort of an array of files using the 39 * {@link #DEFAULT_REVERSE} singleton instance: 40 * </p> 41 * <pre> 42 * File[] array = ... 43 * ((AbstractFileComparator) DefaultFileComparator.DEFAULT_REVERSE).sort(array); 44 * </pre> 45 * <h2>Deprecating Serialization</h2> 46 * <p> 47 * <em>Serialization is deprecated and will be removed in 3.0.</em> 48 * </p> 49 * 50 * @since 1.4 51 */ 52 public class DefaultFileComparator extends AbstractFileComparator implements Serializable { 53 54 private static final long serialVersionUID = 3260141861365313518L; 55 56 /** Singleton default comparator instance */ 57 public static final Comparator<File> DEFAULT_COMPARATOR = new DefaultFileComparator(); 58 59 /** Singleton reverse default comparator instance */ 60 public static final Comparator<File> DEFAULT_REVERSE = new ReverseFileComparator(DEFAULT_COMPARATOR); 61 62 /** 63 * Constructs a new instance. 64 */ 65 public DefaultFileComparator() { 66 // empty 67 } 68 69 /** 70 * Compares the two files using the {@link File#compareTo(File)} method. 71 * 72 * @param file1 The first file to compare 73 * @param file2 The second file to compare 74 * @return the result of calling file1's 75 * {@link File#compareTo(File)} with file2 as the parameter. 76 */ 77 @Override 78 public int compare(final File file1, final File file2) { 79 return file1.compareTo(file2); 80 } 81 }