/*
* 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.IOCase;
/**
* Compare the <b>path</b> of two files for order (see {@link File#getPath()}).
* <p>
* This comparator can be used to sort lists or arrays of files
* by their path either in a case-sensitive, case-insensitive or
* system dependant case sensitive way. A number of singleton instances
* are provided for the various case sensitivity options (using {@link IOCase})
* and the reverse of those options.
* <p>
* Example of a <i>case-sensitive</i> file path sort using the
* {@link #PATH_COMPARATOR} singleton instance:
* <pre>
* List<File> list = ...
* PathFileComparator.PATH_COMPARATOR.sort(list);
* </pre>
* <p>
* Example of a <i>reverse case-insensitive</i> file path sort using the
* {@link #PATH_INSENSITIVE_REVERSE} singleton instance:
* <pre>
* File[] array = ...
* PathFileComparator.PATH_INSENSITIVE_REVERSE.sort(array);
* </pre>
* <p>
*
* @version $Revision: 723942 $ $Date: 2008-12-05 20:24:06 -0500 (Fri, 05 Dec 2008) $
* @since Commons IO 1.4
*/
public class PathFileComparator extends AbstractFileComparator implements Serializable {
/** Case-sensitive path comparator instance (see {@link IOCase#SENSITIVE}) */
public static final Comparator<File> PATH_COMPARATOR = new PathFileComparator();
/** Reverse case-sensitive path comparator instance (see {@link IOCase#SENSITIVE}) */
public static final Comparator<File> PATH_REVERSE = new ReverseComparator(PATH_COMPARATOR);
/** Case-insensitive path comparator instance (see {@link IOCase#INSENSITIVE}) */
public static final Comparator<File> PATH_INSENSITIVE_COMPARATOR = new PathFileComparator(IOCase.INSENSITIVE);
/** Reverse case-insensitive path comparator instance (see {@link IOCase#INSENSITIVE}) */
public static final Comparator<File> PATH_INSENSITIVE_REVERSE = new ReverseComparator(PATH_INSENSITIVE_COMPARATOR);
/** System sensitive path comparator instance (see {@link IOCase#SYSTEM}) */
public static final Comparator<File> PATH_SYSTEM_COMPARATOR = new PathFileComparator(IOCase.SYSTEM);
/** Reverse system sensitive path comparator instance (see {@link IOCase#SYSTEM}) */
public static final Comparator<File> PATH_SYSTEM_REVERSE = new ReverseComparator(PATH_SYSTEM_COMPARATOR);
/** Whether the comparison is case sensitive. */
private final IOCase caseSensitivity;
/**
* Construct a case sensitive file path comparator instance.
*/
public PathFileComparator() {
this.caseSensitivity = IOCase.SENSITIVE;
}
/**
* Construct a file path comparator instance with the specified case-sensitivity.
*
* @param caseSensitivity how to handle case sensitivity, null means case-sensitive
*/
public PathFileComparator(IOCase caseSensitivity) {
this.caseSensitivity = caseSensitivity == null ? IOCase.SENSITIVE : caseSensitivity;
}
/**
* Compare the paths of two files the specified case sensitivity.
*
* @param file1 The first file to compare
* @param file2 The second file to compare
* @return a negative value if the first file's path
* is less than the second, zero if the paths are the
* same and a positive value if the first files path
* is greater than the second file.
*
*/
public int compare(File file1, File file2) {
return caseSensitivity.checkCompareTo(file1.getPath(), file2.getPath());
}
/**
* String representation of this file comparator.
*
* @return String representation of this file comparator
*/
@Override
public String toString() {
return super.toString() + "[caseSensitivity=" + caseSensitivity + "]";
}
}
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