java.nio.file

---

1. Create a Path:

Path path = Paths.get("my/file.txt");

2. Get Absolute Path:

Path absolutePath = path.toAbsolutePath();

3. Get Directory Name:

Path directory = path.getParent();

4. Get File Name:

Path fileName = path.getFileName();

5. Check if File Exists:

boolean exists = Files.exists(path);

6. Create a Directory:

Files.createDirectories(path);

7. Create a File:

Files.createFile(path);

8. Delete a File:

Files.delete(path);

9. Copy a File:

Files.copy(sourcePath, targetPath);

10. Move a File:

Files.move(sourcePath, targetPath);

11. Read a Text File:

List<String> lines = Files.readAllLines(path);

12. Write a Text File:

Files.write(path, lines);

13. Create a Random Access File:

RandomAccessFile raf = new RandomAccessFile(path, "rw");

14. Read Bytes from a File:

byte[] bytes = Files.readAllBytes(path);

15. Write Bytes to a File:

Files.write(path, bytes);

16. Check if File is Regular:

boolean isRegularFile = Files.isRegularFile(path);

17. Check if File is Hidden:

boolean isHidden = Files.isHidden(path);

18. Get File Size:

long size = Files.size(path);

19. Get File Last Modified Time:

Instant lastModified = Files.getLastModifiedTime(path);

20. Set File Last Modified Time:

Files.setLastModifiedTime(path, Instant.now());

21. Create a Temp File:

Path tempFile = Files.createTempFile("prefix", "suffix");

22. Create a Temp Directory:

Path tempDir = Files.createTempDirectory("prefix");

23. Walk a File Tree:

Files.walk(path)
  .forEach(System.out::println);

24. Find Files with a Glob:

Files.find(path, 10,
  (p, a) -> p.getFileName().toString().startsWith("file"))
  .forEach(System.out::println);

25. Find Files with a Filter:

Files.newDirectoryStream(path, p -> p.toString().endsWith(".txt"))
  .forEach(System.out::println);

26. Copy a Directory:

Files.walk(sourceDir)
  .forEach(p -> Files.copy(p, targetDir.resolve(p)));

27. Zip a Directory:

try (ZipOutputStream zos = new ZipOutputStream(Files.newOutputStream(zipFile))) {
  Files.walk(dir)
    .filter(Files::isRegularFile)
    .forEach(p -> {
      zos.putNextEntry(new ZipEntry(p.toString()));
      Files.copy(p, zos);
    });
}

28. Unzip a File:

try (ZipInputStream zis = new ZipInputStream(Files.newInputStream(zipFile))) {
  ZipEntry entry;
  while ((entry = zis.getNextEntry()) != null) {
    Path targetPath = Paths.get(entry.getName());
    Files.copy(zis, targetPath);
  }
}

29. Download a File from a URL:

URL url = new URL("http://example.com/file.txt");
Path targetPath = Paths.get("file.txt");
Files.copy(url.openStream(), targetPath);

30. Upload a File to a Server:

URLConnection urlConnection = new URL("http://example.com/upload").openConnection();
urlConnection.setDoOutput(true);
Files.copy(sourcePath, urlConnection.getOutputStream());

31. Create a Symbolic Link:

Files.createSymbolicLink(targetPath, linkPath);

32. Get File Owner:

UserPrincipal owner = Files.getOwner(path);

33. Set File Owner:

Files.setOwner(path, owner);

34. Get File Permissions:

Set<PosixFilePermission> permissions = Files.getPosixFilePermissions(path);

35. Set File Permissions:

Files.setPosixFilePermissions(path, permissions);

36. Check if File is Symbolic Link:

boolean isSymbolicLink = Files.isSymbolicLink(path);

37. Get File Symbolic Link Target:

Path target = Files.readSymbolicLink(path);

38. Create a File Lock:

try (FileLock lock = Files.newOutputStream(path).lock()) {
  // Do something with the file
}

39. Check if File is Open:

boolean isOpen = Files.isOpen(path);

40. Create a Watch Service:

try (WatchService watchService = FileSystems.getDefault().newWatchService()) {
  path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);
  while (true) {
    WatchKey key = watchService.take();
    for (WatchEvent<?> event : key.pollEvents()) {
      // Handle event
    }
  }
}

41. Create a File Attribute View:

try (FileAttributeView view = Files.getFileAttributeView(path, BasicFileAttributeView.class)) {
  // Get or set file attributes
}

42. Get File System Root Directory:

Path root = path.getFileSystem().getRootDirectories().iterator().next();

43. Get File System Separator:

String separator = path.getFileSystem().getSeparator();

44. Get File System Name:

String name = path.getFileSystem().name();

45. Create a Secure Channel:

try (FileChannel channel = FileChannel.open(path, StandardOpenOption.READ, StandardOpenOption.WRITE)) {
  channel.write(ByteBuffer.wrap("Hello World".getBytes()));
}

46. Map a File to Memory:

try (FileChannel channel = FileChannel.open(path, StandardOpenOption.READ)) {
  MappedByteBuffer mbb = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());
}

47. Create a ByteChannel:

try (ByteChannel channel = FileChannel.open(path, StandardOpenOption.READ)) {
  // Read or write bytes
}

48. Get File Store:

FileStore store = Files.getFileStore(path);

49. Get Usable Space on File Store:

long usableSpace = store.getUsableSpace();

50. Get Total Space on File Store:

long totalSpace = store.getTotalSpace();