content: /*
   * 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&lt;File&gt; 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 $Id: LastModifiedFileComparator.java 1304052 2012-03-22 20:55:29Z ggregory $
   * @since 1.4
   */
  public class LastModifiedFileComparator extends AbstractFileComparator implements Serializable {
  
      /**
  	 * 
  	 */
  	private static final long serialVersionUID = 1L;
  
  	/** 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;
          }
      }
  }
  