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 * @key randomness
31 */
32import java.nio.file.*;
33import java.nio.file.attribute.BasicFileAttributes;
34import java.io.IOException;
35import java.util.HashSet;
36import java.util.Random;
37import java.util.Set;
38
39public class SkipSubtree {
40
41    static final Random rand = new Random();
42    static final Set<Path> skipped = new HashSet<>();
43
44    // check if this path should have been skipped
45    static void check(Path path) {
46        do {
47            if (skipped.contains(path))
48                throw new RuntimeException(path + " should not have been visited");
49            path = path.getParent();
50        } while (path != null);
51    }
52
53    // indicates if the subtree should be skipped
54    static boolean skip(Path path) {
55        if (rand.nextInt(3) == 0) {
56            skipped.add(path);
57            return true;
58        }
59        return false;
60    }
61
62    public static void main(String[] args) throws Exception {
63        Path top = CreateFileTree.create();
64        try {
65            test(top);
66        } finally {
67            TestUtil.removeAll(top);
68        }
69    }
70
71    static void test(final Path start) throws IOException {
72        Files.walkFileTree(start, new SimpleFileVisitor<Path>() {
73            @Override
74            public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
75                check(dir);
76                if (skip(dir))
77                    return FileVisitResult.SKIP_SUBTREE;
78                return FileVisitResult.CONTINUE;
79            }
80            @Override
81            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
82                check(file);
83                return FileVisitResult.CONTINUE;
84            }
85            @Override
86            public FileVisitResult postVisitDirectory(Path dir, IOException x) {
87                if (x != null)
88                    throw new RuntimeException(x);
89                check(dir);
90                return FileVisitResult.CONTINUE;
91            }
92        });
93    }
94}
95