If you find that you get an Exception containing something like

Exception in thread "main" java.nio.file.AccessDeniedException: /tmp/pulse-2L9K88eMlGn7

with Files.walkFileTree when you have called that method wanting it to work recursively, you might find there are two reason for this happening:
a. there's a directory along the walk to which you have no read access
b. you have not implemented FileVisitor.visitFileFailed

If both a. and b. are the case, what happens is that the aforementioned Exception is thrown and the walk is terminated.

The solution is to ensure that you implement FileVisitor.visitFileFailed. Even when there is an unreadable directory on the walk, it can continue unless explicitly prevented from doing so. The following code shows how to recurse a Path without it terminating in the presence of an unreadable directory and it can be downloaded HERE

import java.io.File;
import java.io.IOException;

import java.nio.file.AccessDeniedException;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;

public class Recurse {
    public static void main(String[] args) throws IOException {
        Path start = new File(args[0]).toPath();
            new SimpleFileVisitor<Path>() {
                public FileVisitResult visitFile(Path file,
                    BasicFileAttributes attrs) throws IOException {
                    System.out.printf("Visiting file %s\n", file);

                    return FileVisitResult.CONTINUE;

                public FileVisitResult visitFileFailed(Path file, IOException e)
                    throws IOException {
                    System.err.printf("Visiting failed for %s\n", file);

                    return FileVisitResult.SKIP_SUBTREE;

                public FileVisitResult preVisitDirectory(Path dir,
                    BasicFileAttributes attrs) throws IOException {
                    System.out.printf("About to visit directory %s\n", dir);

                    return FileVisitResult.CONTINUE;