com.github.xbn.examples.io.non_xbn.SizeOrderAllFilesInDirXmpl.java Source code

Introduction

Here is the source code for com.github.xbn.examples.io.non_xbn.SizeOrderAllFilesInDirXmpl.java

Source

/*license*\
   XBN-Java: Copyright (C) 2014, Jeff Epstein (aliteralmind __DASH__ github __AT__ yahoo __DOT__ com)
    
   This software is dual-licensed under the:
   - Lesser General Public License (LGPL) version 3.0 or, at your option, any later version;
   - Apache Software License (ASL) version 2.0.
    
   Either license may be applied at your discretion. More information may be found at
   - http://en.wikipedia.org/wiki/Multi-licensing.
    
   The text of both licenses is available in the root directory of this project, under the names "LICENSE_lgpl-3.0.txt" and "LICENSE_asl-2.0.txt". The latest copies may be downloaded at:
   - LGPL 3.0: https://www.gnu.org/licenses/lgpl-3.0.txt
   - ASL 2.0: http://www.apache.org/licenses/LICENSE-2.0.txt
\*license*/
package com.github.xbn.examples.io.non_xbn;

import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.TreeMap;
import org.apache.commons.io.FileUtils;

/**
   <p>Demonstration of listing all files in a directory, in size order, using a {@link java.util.Map} in which each item is a list of values (multiple values per key). This is an answer to (viewed 1/2/2014)
   <br/> &nbsp; &nbsp; {@code <a href="http://stackoverflow.com/questions/20889571/java-list-of-subdirectories-and-files-within-a-path-size">http://stackoverflow.com/questions/20889571/java-list-of-subdirectories-and-files-within-a-path-size</a>}</p>
    
   <p>java com.github.xbn.examples.io.SizeOrderAllFilesInDirXmpl</p>
    
 * @since  0.1.0
 * @author  Copyright (C) 2014, Jeff Epstein ({@code aliteralmind __DASH__ github __AT__ yahoo __DOT__ com}), dual-licensed under the LGPL (version 3.0 or later) or the ASL (version 2.0). See source code for details. <a href="http://xbnjava.aliteralmind.com">{@code http://xbnjava.aliteralmind.com}</a>, <a href="https://github.com/aliteralmind/xbnjava">{@code https://github.com/aliteralmind/xbnjava}</a>
 **/
public class SizeOrderAllFilesInDirXmpl {
    public static final void main(String[] ignored) {
        File fDir = (new File("R:\\jeffy\\programming\\sandbox\\xbnjava\\xbn\\"));
        Collection<File> cllf = FileUtils.listFiles(fDir, (new String[] { "java" }), true);

        //Add all file paths to a Map, keyed by size.
        //It's actually a map of lists-of-files, to
        //allow multiple files that happen to have the
        //same length.

        TreeMap<Long, List<File>> tmFilesBySize = new TreeMap<Long, List<File>>();
        Iterator<File> itrf = cllf.iterator();
        while (itrf.hasNext()) {
            File f = itrf.next();
            Long LLen = f.length();
            if (!tmFilesBySize.containsKey(LLen)) {
                ArrayList<File> alf = new ArrayList<File>();
                alf.add(f);
                tmFilesBySize.put(LLen, alf);
            } else {
                tmFilesBySize.get(LLen).add(f);
            }
        }

        //Iterate backwards by key through the map. For each
        //List<File>, iterate through the files, printing out
        //its size and path.

        ArrayList<Long> alSize = new ArrayList<Long>(tmFilesBySize.keySet());
        for (int i = alSize.size() - 1; i >= 0; i--) {
            itrf = tmFilesBySize.get(alSize.get(i)).iterator();
            while (itrf.hasNext()) {
                File f = itrf.next();
                System.out.println(f.length() + ": " + f.getPath());
            }
        }
    }
}