1 /*
   2  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 import java.nio.file.*;
  25 import java.nio.file.attribute.*;
  26 import java.io.IOException;
  27 import java.util.*;
  28 
  29 /**
  30  * Invokes Files.walkFileTree to traverse a file tree and prints
  31  * each of the directories and files. The -follow option causes symbolic
  32  * links to be followed and the -printCycles option will print links
  33  * where the target of the link is an ancestor directory.
  34  */
  35 
  36 public class PrintFileTree {
  37 
  38     public static void main(String[] args) throws Exception {
  39         boolean followLinks = false;
  40         boolean printCycles = false;
  41         int i = 0;
  42         while (i < (args.length-1)) {
  43             switch (args[i]) {
  44                 case "-follow"      : followLinks = true; break;
  45                 case "-printCycles" : printCycles = true;  break;
  46                 default:
  47                     throw new RuntimeException(args[i] + " not recognized");
  48             }
  49             i++;
  50         }
  51         Path dir = Paths.get(args[i]);
  52 
  53         Set<FileVisitOption> options = new HashSet<FileVisitOption>();
  54         if (followLinks)
  55             options.add(FileVisitOption.FOLLOW_LINKS);
  56 
  57         final boolean reportCycles = printCycles;
  58         Files.walkFileTree(dir, options, Integer.MAX_VALUE, new FileVisitor<Path>() {
  59             @Override
  60             public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
  61                 System.out.println(dir);
  62                 return FileVisitResult.CONTINUE;
  63             }
  64             @Override
  65             public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
  66                 if (!attrs.isDirectory() || reportCycles)
  67                     System.out.println(file);
  68                 return FileVisitResult.CONTINUE;
  69             }
  70             @Override
  71             public FileVisitResult postVisitDirectory(Path dir, IOException exc)
  72                 throws IOException
  73             {
  74                 if (exc != null)
  75                     throw exc;
  76                 return FileVisitResult.CONTINUE;
  77             }
  78             @Override
  79             public FileVisitResult visitFileFailed(Path file, IOException exc)
  80                 throws IOException
  81             {
  82                 if (reportCycles && (exc instanceof FileSystemLoopException)) {
  83                     System.out.println(file);
  84                     return FileVisitResult.CONTINUE;
  85                 }
  86                 throw exc;
  87             }
  88         });
  89     }
  90 }