JAVA.md

Java Key Features (2014–2023)

Welcome to the Java Key Features overview!

Java Feature Timeline

Java 8 (2014)

• 🔄 Lambdas

  List<String> names = Arrays.asList("John", "Jane", "Jake");
  names.forEach(name -> System.out.println(name));

• 🌊 Streams API

  List<String> filtered = names.stream()
      .filter(name -> name.startsWith("J"))
      .collect(Collectors.toList());

• 🕒 Date and Time API

  LocalDate today = LocalDate.now();
  LocalDate nextWeek = today.plusWeeks(1);

• 🔧 Default Methods in Interfaces

  interface Vehicle {
      default void start() {
          System.out.println("Vehicle starting...");
      }
  }

Java 9 (2017)

• 📦 Module System

  module com.example.myapp {
      requires java.base;
  }

• 💻 JShell (Interactive REPL)

  jshell> int x = 5;
  jshell> System.out.println(x * 2);

• 🚀 Improved JVM Performance

Java 10 (2018)

• 📝 Local Variable Type Inference

  var list = List.of("A", "B", "C");
  for (var item : list) {
      System.out.println(item);
  }

• ♻️ G1 Garbage Collector Improvements
• 📦 Application Class-Data Sharing (AppCDS)

Java 11 (2018 - LTS)

• 🌐 HTTP Client API

  HttpClient client = HttpClient.newHttpClient();
  HttpRequest request = HttpRequest.newBuilder()
      .uri(URI.create("https://example.com"))
      .build();
  HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

• ❌ Removal of Legacy Features
  • ❌ Applet API
• 🏆 Long-Term Support (LTS)

Java 12 (2019)

• 🔄 Switch Expressions (Preview)

  int result = switch (day) {
      case MONDAY, FRIDAY -> 6;
      case TUESDAY -> 7;
      default -> 0;
  };

• ♻️ Shenandoah Garbage Collector
• 🚀 Performance Enhancements (JEP 189)

Java 13 (2019)

• 📄 Text Blocks (Preview)

  String json = """
  {
    "name": "John",
    "age": 30
  }
  """;

• 📦 Dynamic CDS Archives
• 🌐 Improved Socket API

Java 14 (2020)

• 🔄 Records (Preview)

  record Point(int x, int y) {}

• 🔍 Pattern Matching (Preview)

  if (obj instanceof String s) {
      System.out.println(s.toUpperCase());
  }

• 💡 Helpful NullPointerException Messages

Java 15 (2020)

• 📄 Text Blocks Finalized
• 🔒 Sealed Classes (Preview)

  sealed class Shape permits Circle, Rectangle {}

• 🧠 Foreign Memory API (Incubator)

Java 16 (2021)

• 🔄 Records Finalized
• ♻️ Z Garbage Collector for macOS
• 🚀 Foreign Function & Memory API Improvements

Java 17 (2021 - LTS)

• 🔍 Pattern Matching for Switch (Preview)

  String response = switch (obj) {
      case Integer i -> "Integer: " + i;
      case String s -> "String: " + s;
      default -> "Unknown type";
  };

• 🔒 Sealed Classes Finalized
• 🎲 Pseudo-Random Number Generators Improvements
• 🏆 Long-Term Support (LTS)

Java 18 (2022)

• 🔒 Strong Encapsulation of JDK Internals (JEP 400)
• 🌐 Support for Alpine Linux

Java 19 (2022)

• 🧵 Virtual Threads (Preview)

  Thread.startVirtualThread(() -> System.out.println("Hello from virtual thread"));

• 🚀 Continued Foreign Function & Memory API Enhancements

Java 20 (2023)

• 🧵 Virtual Threads Improvements
• 🔍 Pattern Matching Advancements
• 🔄 Enhanced Thread Management

Java 21 (2023 - LTS)

• 🏆 Long-Term Support (LTS)
• 🧵 Virtual Threads (Mainstream Adoption)
• 🕸️ Structured Concurrency