TerminateWalk.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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/*
 * @test
 * @summary Unit test for Files.walkFileTree to test TERMINATE return value
 * @library ../..
 * @compile TerminateWalk.java CreateFileTree.java
 * @run main TerminateWalk
 * @key randomness
 */

import java.nio.file.*;
import java.nio.file.attribute.*;
import java.io.IOException;
import java.util.*;

public class TerminateWalk {

    static final Random rand = new Random();
    static boolean terminated;

    static FileVisitResult maybeTerminate() {
        if (terminated)
            throw new RuntimeException("FileVisitor invoked after termination");
        if (rand.nextInt(10) == 0) {
            terminated = true;
            return FileVisitResult.TERMINATE;
        } else {
            return FileVisitResult.CONTINUE;
        }
    }

    public static void main(String[] args) throws Exception {
        Path top = CreateFileTree.create();
        try {
            test(top);
        } finally {
            TestUtil.removeAll(top);
        }
    }

    static void test(Path start) throws IOException {
        Files.walkFileTree(start, new SimpleFileVisitor<Path>() {
            @Override
            public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
                return maybeTerminate();
            }
            @Override
            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
                return maybeTerminate();
            }
            @Override
            public FileVisitResult postVisitDirectory(Path dir, IOException x) {
                return maybeTerminate();
            }
        });
    }
}