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.comparator;
018
019import java.io.File;
020import java.io.Serializable;
021import java.util.Comparator;
022
023/**
024 * Compare two files using the <b>default</b> {@link File#compareTo(File)} method.
025 * <p>
026 * This comparator can be used to sort lists or arrays of files
027 * by using the default file comparison.
028 * <p>
029 * Example of sorting a list of files using the
030 * {@link #DEFAULT_COMPARATOR} singleton instance:
031 * <pre>
032 *       List&lt;File&gt; list = ...
033 *       ((AbstractFileComparator) DefaultFileComparator.DEFAULT_COMPARATOR).sort(list);
034 * </pre>
035 * <p>
036 * Example of doing a <i>reverse</i> sort of an array of files using the
037 * {@link #DEFAULT_REVERSE} singleton instance:
038 * <pre>
039 *       File[] array = ...
040 *       ((AbstractFileComparator) DefaultFileComparator.DEFAULT_REVERSE).sort(array);
041 * </pre>
042 * <p>
043 *
044 * @since 1.4
045 */
046public class DefaultFileComparator extends AbstractFileComparator implements Serializable {
047
048    private static final long serialVersionUID = 3260141861365313518L;
049
050    /** Singleton default comparator instance */
051    public static final Comparator<File> DEFAULT_COMPARATOR = new DefaultFileComparator();
052
053    /** Singleton reverse default comparator instance */
054    public static final Comparator<File> DEFAULT_REVERSE = new ReverseFileComparator(DEFAULT_COMPARATOR);
055
056    /**
057     * Compare the two files using the {@link File#compareTo(File)} method.
058     *
059     * @param file1 The first file to compare
060     * @param file2 The second file to compare
061     * @return the result of calling file1's
062     * {@link File#compareTo(File)} with file2 as the parameter.
063     */
064    @Override
065    public int compare(final File file1, final File file2) {
066        return file1.compareTo(file2);
067    }
068}