/*
* 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 two files using the {@link File#isDirectory()} method.
* <p>
* This comparator can be used to sort lists or arrays by directories and files.
* <p>
* Example of sorting a list of files/directories using the
* {@link #DIRECTORY_COMPARATOR} singleton instance:
* <pre>
* List<File> list = ...
* DirectoryFileComparator.DIRECTORY_COMPARATOR.sort(list);
* </pre>
* <p>
* Example of doing a <i>reverse</i> sort of an array of files/directories using the
* {@link #DIRECTORY_REVERSE} singleton instance:
* <pre>
* File[] array = ...
* DirectoryFileComparator.DIRECTORY_REVERSE.sort(array);
* </pre>
* <p>
*
* @version $Revision$ $Date$
* @since Commons IO 2.0
*/
public class DirectoryFileComparator extends AbstractFileComparator implements Serializable {
/** Singleton default comparator instance */
public static final Comparator<File> DIRECTORY_COMPARATOR = new DirectoryFileComparator();
/** Singleton reverse default comparator instance */
public static final Comparator<File> DIRECTORY_REVERSE = new ReverseComparator(DIRECTORY_COMPARATOR);
/**
* Compare the two files using the {@link File#isDirectory()} method.
*
* @param file1 The first file to compare
* @param file2 The second file to compare
* @return the result of calling file1's
* {@link File#compareTo(File)} with file2 as the parameter.
*/
public int compare(File file1, File file2) {
return (getType(file1) - getType(file2));
}
/**
* Convert type to numeric value.
*
* @param file The file
* @return 1 for directories and 2 for files
*/
private int getType(File file) {
if (file.isDirectory()) {
return 1;
} else {
return 2;
}
}
}
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