public static boolean equal(File file1, File file2) throws IOException {
    checkNotNull(file1);
    checkNotNull(file2);
    if (file1 == file2 || file1.equals(file2)) {
      return true;
    }

    /*
     * Some operating systems may return zero as the length for files denoting system-dependent
     * entities such as devices or pipes, in which case we must fall back on comparing the bytes
     * directly.
     */

    File dir2 = newFile("dir-1/dir-2");

    assertThat(Files.fileTraverser().breadthFirst(rootDir))
        .containsExactly(rootDir, fileA, fileB, dir1, dir2);
  }

  @CanIgnoreReturnValue
  private File newDir(String name) {
    File file = new File(rootDir, name);
    file.mkdir();
    return file;
  }

  @CanIgnoreReturnValue
  private File newFile(String name) throws IOException {

    File dir2 = newFile("dir-1/dir-2");

    assertThat(Files.fileTraverser().breadthFirst(rootDir))
        .containsExactly(rootDir, fileA, fileB, dir1, dir2);
  }

  @CanIgnoreReturnValue
  private File newDir(String name) {
    File file = new File(rootDir, name);
    file.mkdir();
    return file;
  }

  @CanIgnoreReturnValue
  private File newFile(String name) throws IOException {

    Files.createParentDirs(file);
  }

  public void testCreateParentDirs_relativePath() throws IOException {
    File file = file("nonexistent.file");
    assertNull(file.getParentFile());
    assertNotNull(file.getCanonicalFile().getParentFile());
    Files.createParentDirs(file);
  }

  public void testCreateParentDirs_noParentsNeeded() throws IOException {
    File file = file(getTempDir(), "nonexistent.file");

    Path file = rootDir.resolve("file-that-doesnt-exist");

    assertThat(MoreFiles.fileTraverser().breadthFirst(file)).containsExactly(file);
  }

  public void testFileTraverser_file() throws Exception {
    Path file = newFile("some-file");

    assertThat(MoreFiles.fileTraverser().breadthFirst(file)).containsExactly(file);
  }

import java.nio.file.FileSystems;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.attribute.FileTime;
import java.util.EnumSet;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

        try ( SmbFile f = createTestDirectory() ) {
            try {
                SmbFile[] files = f.listFiles(new DosFileFilter("*.txt", 0));
                assertNotNull(files);
                assertEquals(0, files.length);

                files = f.listFiles();
                assertNotNull(files);
                assertEquals(0, files.length);
            }
            finally {
                f.delete();
            }

             * source files.
             */
            if (Files.isDirectory(file)) {
                Map<Path, String> names = new HashMap<>();
                try (Stream<Path> subdirs = Files.list(file)) {
                    subdirs.filter(Files::isDirectory).forEach((subdir) -> {
                        Path mf = subdir.resolve(MODULE_INFO);
                        if (Files.isRegularFile(mf)) {

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import java.io.File;
import java.io.IOException;
import java.nio.file.DirectoryNotEmptyException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;

     * @param files List of POM files.
     * @param request The {@link MavenExecutionRequest}
     * @return A list of projects that have been found in the specified POM files.
     * @throws ProjectBuildingException In case the POMs are not used.
     */
    List<MavenProject> selectProjects(List<File> files, MavenExecutionRequest request) throws ProjectBuildingException;