1 /*
   2  * Copyright (c) 2013, 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 /*
  25  * @test
  26  * @summary Unit test for Files.walkFileTree to test SKIP_SUBTREE return value
  27  * @library ../..
  28  * @compile SkipSubtree.java CreateFileTree.java
  29  * @run main SkipSubtree
  30  */
  31 import java.nio.file.*;
  32 import java.nio.file.attribute.BasicFileAttributes;
  33 import java.io.IOException;
  34 import java.util.HashSet;
  35 import java.util.Random;
  36 import java.util.Set;
  37 
  38 public class SkipSubtree {
  39 
  40     static final Random rand = new Random();
  41     static final Set<Path> skipped = new HashSet<>();
  42 
  43     // check if this path should have been skipped
  44     static void check(Path path) {
  45         do {
  46             if (skipped.contains(path))
  47                 throw new RuntimeException(path + " should not have been visited");
  48             path = path.getParent();
  49         } while (path != null);
  50     }
  51 
  52     // indicates if the subtree should be skipped
  53     static boolean skip(Path path) {
  54         if (rand.nextInt(3) == 0) {
  55             skipped.add(path);
  56             return true;
  57         }
  58         return false;
  59     }
  60 
  61     public static void main(String[] args) throws Exception {
  62         Path top = CreateFileTree.create();
  63         try {
  64             test(top);
  65         } finally {
  66             TestUtil.removeAll(top);
  67         }
  68     }
  69 
  70     static void test(final Path start) throws IOException {
  71         Files.walkFileTree(start, new SimpleFileVisitor<Path>() {
  72             @Override
  73             public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
  74                 check(dir);
  75                 if (skip(dir))
  76                     return FileVisitResult.SKIP_SUBTREE;
  77                 return FileVisitResult.CONTINUE;
  78             }
  79             @Override
  80             public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
  81                 check(file);
  82                 return FileVisitResult.CONTINUE;
  83             }
  84             @Override
  85             public FileVisitResult postVisitDirectory(Path dir, IOException x) {
  86                 if (x != null)
  87                     throw new RuntimeException(x);
  88                 check(dir);
  89                 return FileVisitResult.CONTINUE;
  90             }
  91         });
  92     }
  93 }