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  * @compile SkipSubtree.java CreateFileTree.java

    28  * @run main SkipSubtree

    29  */

    30 import java.nio.file.*;

    31 import java.nio.file.attribute.BasicFileAttributes;

    32 import java.io.IOException;

    33 import java.util.HashSet;

    34 import java.util.Random;

    35 import java.util.Set;

    36 

    37 public class SkipSubtree {

    38 

    39     static final Random rand = new Random();

    40     static final Set<Path> skipped = new HashSet<>();

    41 

    42     // check if this path should have been skipped

    43     static void check(Path path) {

    44         do {

    45             if (skipped.contains(path))

    46                 throw new RuntimeException(path + " should not have been visited");

    47             path = path.getParent();

    48         } while (path != null);

    49     }

    50 

    51     // indicates if the subtree should be skipped

    52     static boolean skip(Path path) {

    53         if (rand.nextInt(3) == 0) {

    54             skipped.add(path);

    55             return true;

    56         }

    57         return false;

    58     }

    59 

    60     public static void main(String[] args) throws Exception {

    61         Path dir = CreateFileTree.create();

    62 

    63         Files.walkFileTree(dir, new SimpleFileVisitor<Path>() {

    64             @Override

    65             public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {

    66                 check(dir);

    67                 if (skip(dir))

    68                     return FileVisitResult.SKIP_SUBTREE;

    69                 return FileVisitResult.CONTINUE;

    70             }

    71             @Override

    72             public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {

    73                 check(file);

    74                 return FileVisitResult.CONTINUE;

    75             }

    76             @Override

    77             public FileVisitResult postVisitDirectory(Path dir, IOException x) {

    78                 if (x != null)

    79                     throw new RuntimeException(x);

    80                 check(dir);

    81                 return FileVisitResult.CONTINUE;

    82             }

    83         });

    84     }

    85 }