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Commons IO example source code file (NameFileComparator.java)

This example Commons IO source code file (NameFileComparator.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons IO tags/keywords

comparator, comparator, file, io, name_comparator, name_insensitive_comparator, name_insensitive_reverse, name_system_comparator, name_system_comparator, name_system_reverse, namefilecomparator, namefilecomparator, override, reversecomparator, reversecomparator, util

The Commons IO NameFileComparator.java source code

/*
 * 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>names of two files for order (see {@link File#getName()}).
 * <p>
 * This comparator can be used to sort lists or arrays of files
 * by their name 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 file name sort using the
 * {@link #NAME_COMPARATOR} singleton instance:
 * <pre>
 *       List<File> list = ...
 *       NameFileComparator.NAME_COMPARATOR.sort(list);
 * </pre>
 * <p>
 * Example of a <i>reverse case-insensitive file name sort using the
 * {@link #NAME_INSENSITIVE_REVERSE} singleton instance:
 * <pre>
 *       File[] array = ...
 *       NameFileComparator.NAME_INSENSITIVE_REVERSE.sort(array);
 * </pre>
 * <p>
 *
 * @version $Revision: 723942 $ $Date: 2008-12-06 01:24:06 +0000 (Sat, 06 Dec 2008) $
 * @since Commons IO 1.4
 */
public class NameFileComparator extends AbstractFileComparator implements Serializable {

    /** Case-sensitive name comparator instance (see {@link IOCase#SENSITIVE}) */
    public static final Comparator<File> NAME_COMPARATOR = new NameFileComparator();

    /** Reverse case-sensitive name comparator instance (see {@link IOCase#SENSITIVE}) */
    public static final Comparator<File> NAME_REVERSE = new ReverseComparator(NAME_COMPARATOR);

    /** Case-insensitive name comparator instance (see {@link IOCase#INSENSITIVE}) */
    public static final Comparator<File> NAME_INSENSITIVE_COMPARATOR = new NameFileComparator(IOCase.INSENSITIVE);

    /** Reverse case-insensitive name comparator instance (see {@link IOCase#INSENSITIVE}) */
    public static final Comparator<File> NAME_INSENSITIVE_REVERSE = new ReverseComparator(NAME_INSENSITIVE_COMPARATOR);

    /** System sensitive name comparator instance (see {@link IOCase#SYSTEM}) */
    public static final Comparator<File> NAME_SYSTEM_COMPARATOR = new NameFileComparator(IOCase.SYSTEM);

    /** Reverse system sensitive name comparator instance (see {@link IOCase#SYSTEM}) */
    public static final Comparator<File> NAME_SYSTEM_REVERSE = new ReverseComparator(NAME_SYSTEM_COMPARATOR);

    /** Whether the comparison is case sensitive. */
    private final IOCase caseSensitivity;

    /**
     * Construct a case sensitive file name comparator instance.
     */
    public NameFileComparator() {
        this.caseSensitivity = IOCase.SENSITIVE;
    }

    /**
     * Construct a file name comparator instance with the specified case-sensitivity.
     *
     * @param caseSensitivity  how to handle case sensitivity, null means case-sensitive
     */
    public NameFileComparator(IOCase caseSensitivity) {
        this.caseSensitivity = caseSensitivity == null ? IOCase.SENSITIVE : caseSensitivity;
    }

    /**
     * Compare the names of two files with 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 name
     * is less than the second, zero if the names are the
     * same and a positive value if the first files name
     * is greater than the second file.
     */
    public int compare(File file1, File file2) {
        return caseSensitivity.checkCompareTo(file1.getName(), file2.getName());
    }

    /**
     * String representation of this file comparator.
     *
     * @return String representation of this file comparator
     */
    @Override
    public String toString() {
        return super.toString() + "[caseSensitivity=" + caseSensitivity + "]";
    }
}

Other Commons IO examples (source code examples)

Here is a short list of links related to this Commons IO NameFileComparator.java source code file:



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