/*
* 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.FileUtils;
/**
* Compare the <b>length/size</b> of two files for order (see
* {@link File#length()} and {@link FileUtils#sizeOfDirectory(File)}).
* <p>
* This comparator can be used to sort lists or arrays of files
* by their length/size.
* <p>
* Example of sorting a list of files using the
* {@link #SIZE_COMPARATOR} singleton instance:
* <pre>
* List<File> list = ...
* SizeFileComparator.SIZE_COMPARATOR.sort(list);
* </pre>
* <p>
* Example of doing a <i>reverse</i> sort of an array of files using the
* {@link #SIZE_REVERSE} singleton instance:
* <pre>
* File[] array = ...
* SizeFileComparator.SIZE_REVERSE.sort(array);
* </pre>
* <p>
* <strong>N.B.</strong> Directories are treated as <b>zero size</b> unless
* <code>sumDirectoryContents</code> is <code>true</code>.
*
* @version $Revision: 723942 $ $Date: 2008-12-05 20:24:06 -0500 (Fri, 05 Dec 2008) $
* @since Commons IO 1.4
*/
public class SizeFileComparator extends AbstractFileComparator implements Serializable {
/** Size comparator instance - directories are treated as zero size */
public static final Comparator<File> SIZE_COMPARATOR = new SizeFileComparator();
/** Reverse size comparator instance - directories are treated as zero size */
public static final Comparator<File> SIZE_REVERSE = new ReverseComparator(SIZE_COMPARATOR);
/**
* Size comparator instance which sums the size of a directory's contents
* using {@link FileUtils#sizeOfDirectory(File)}
*/
public static final Comparator<File> SIZE_SUMDIR_COMPARATOR = new SizeFileComparator(true);
/**
* Reverse size comparator instance which sums the size of a directory's contents
* using {@link FileUtils#sizeOfDirectory(File)}
*/
public static final Comparator<File> SIZE_SUMDIR_REVERSE = new ReverseComparator(SIZE_SUMDIR_COMPARATOR);
/** Whether the sum of the directory's contents should be calculated. */
private final boolean sumDirectoryContents;
/**
* Construct a file size comparator instance (directories treated as zero size).
*/
public SizeFileComparator() {
this.sumDirectoryContents = false;
}
/**
* Construct a file size comparator instance specifying whether the size of
* the directory contents should be aggregated.
* <p>
* If the <code>sumDirectoryContents</code> is <code>true</code> The size of
* directories is calculated using {@link FileUtils#sizeOfDirectory(File)}.
*
* @param sumDirectoryContents <code>true</code> if the sum of the directoryies contents
* should be calculated, otherwise <code>false</code> if directories should be treated
* as size zero (see {@link FileUtils#sizeOfDirectory(File)}).
*/
public SizeFileComparator(boolean sumDirectoryContents) {
this.sumDirectoryContents = sumDirectoryContents;
}
/**
* Compare the length 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 length
* is less than the second, zero if the lengths are the
* same and a positive value if the first files length
* is greater than the second file.
*
*/
public int compare(File file1, File file2) {
long size1 = 0;
if (file1.isDirectory()) {
size1 = sumDirectoryContents && file1.exists() ? FileUtils.sizeOfDirectory(file1) : 0;
} else {
size1 = file1.length();
}
long size2 = 0;
if (file2.isDirectory()) {
size2 = sumDirectoryContents && file2.exists() ? FileUtils.sizeOfDirectory(file2) : 0;
} else {
size2 = file2.length();
}
long result = size1 - size2;
if (result < 0) {
return -1;
} else if (result > 0) {
return 1;
} else {
return 0;
}
}
/**
* String representation of this file comparator.
*
* @return String representation of this file comparator
*/
@Override
public String toString() {
return super.toString() + "[sumDirectoryContents=" + sumDirectoryContents + "]";
}
}
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