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 }