28 — File I/O & NIO

1Bytes  → InputStream / OutputStream     (images, binary)2Chars  → Reader / Writer                (text, charset-aware)

1// Read all text (modern)2String content = Files.readString(path, StandardCharsets.UTF_8);3 4// Write text5Files.writeString(path, "hello", StandardCharsets.UTF_8);6 7// Stream lines lazily8try (Stream<String> lines = Files.lines(path)) {9    lines.filter(l -> !l.isBlank()).forEach(System.out::println);10}11 12// Always use try-with-resources13try (var in = Files.newInputStream(path)) {14    byte[] data = in.readAllBytes();15}