org.apache.commons.io.comparator.LastModifiedFileComparator Maven / Gradle / Ivy
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.io.comparator;
import java.io.File;
import java.io.Serializable;
import java.util.Comparator;
import org.apache.commons.io.FileUtils;
/**
* Compare the last modified date/time of two files for order
* (see {@link FileUtils#lastModifiedUnchecked(File)}).
*
* This comparator can be used to sort lists or arrays of files
* by their last modified date/time.
*
* Example of sorting a list of files using the
* {@link #LASTMODIFIED_COMPARATOR} singleton instance:
*
* List<File> list = ...
* ((AbstractFileComparator) LastModifiedFileComparator.LASTMODIFIED_COMPARATOR).sort(list);
*
*
* Example of doing a reverse sort of an array of files using the
* {@link #LASTMODIFIED_REVERSE} singleton instance:
*
* File[] array = ...
* ((AbstractFileComparator) LastModifiedFileComparator.LASTMODIFIED_REVERSE).sort(array);
*
*
*
* @since 1.4
*/
public class LastModifiedFileComparator extends AbstractFileComparator implements Serializable {
private static final long serialVersionUID = 7372168004395734046L;
/** Last modified comparator instance. */
public static final Comparator LASTMODIFIED_COMPARATOR = new LastModifiedFileComparator();
/** Reverse last modified comparator instance. */
public static final Comparator LASTMODIFIED_REVERSE = new ReverseFileComparator(LASTMODIFIED_COMPARATOR);
/**
* Compares the last the last modified date/time of two files.
*
* @param file1 The first file to compare.
* @param file2 The second file to compare.
* @return a negative value if the first file's last modified date/time is less than the second, zero if the last
* modified date/time are the same and a positive value if the first files last modified date/time is
* greater than the second file.
*/
@Override
public int compare(final File file1, final File file2) {
final long result = FileUtils.lastModifiedUnchecked(file1) - FileUtils.lastModifiedUnchecked(file2);
if (result < 0) {
return -1;
}
if (result > 0) {
return 1;
}
return 0;
}
}