/*
* 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;
/**
* Compare the <b>last modified date/time</b> of two files for order
* (see {@link File#lastModified()}).
* <p>
* This comparator can be used to sort lists or arrays of files
* by their last modified date/time.
* <p>
* Example of sorting a list of files using the
* {@link #LASTMODIFIED_COMPARATOR} singleton instance:
* <pre>
* List<File> list = ...
* LastModifiedFileComparator.LASTMODIFIED_COMPARATOR.sort(list);
* </pre>
* <p>
* Example of doing a <i>reverse</i> sort of an array of files using the
* {@link #LASTMODIFIED_REVERSE} singleton instance:
* <pre>
* File[] array = ...
* LastModifiedFileComparator.LASTMODIFIED_REVERSE.sort(array);
* </pre>
* <p>
*
* @version $Revision: 721626 $ $Date: 2008-11-28 23:46:54 -0500 (Fri, 28 Nov 2008) $
* @since Commons IO 1.4
*/
public class LastModifiedFileComparator extends AbstractFileComparator implements Serializable {
/** Last modified comparator instance */
public static final Comparator<File> LASTMODIFIED_COMPARATOR = new LastModifiedFileComparator();
/** Reverse last modified comparator instance */
public static final Comparator<File> LASTMODIFIED_REVERSE = new ReverseComparator(LASTMODIFIED_COMPARATOR);
/**
* Compare 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 lastmodified date/time
* is less than the second, zero if the lastmodified date/time are the
* same and a positive value if the first files lastmodified date/time
* is greater than the second file.
*
*/
public int compare(File file1, File file2) {
long result = file1.lastModified() - file2.lastModified();
if (result < 0) {
return -1;
} else if (result > 0) {
return 1;
} else {
return 0;
}
}
}
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