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Java 22_ Unwrapped: What You Need to Know.pptx
- 1. Java 22: Unwrapped📦 What You Need to Know 1
- 2. Who Am I? OlehMelnyk ● Software Engineer @Jappware ● Java enthusiast ● Sometimes pretending to be a speaker ● Coffee lover and netflix watcher 2
- 3. 3 🇺🇦 Donate &Support - we’re strong together
- 4. 🔖 Agenda 1. CurrentJDK state overview 2. Finalized/Delivered features 3. Preview/Incubating features 4. Minor API updates 5. Predicting the future 6. Friendly ☺️🍻 discussion 4
- 5. ️ Where weare 5
- 6. ️ Where weare https://inside.java/2024/03/19/the-arrival-of-java-22/ 6
- 7. 🔬 Install andexplore 7
- 8. 8 GraalVM ️ Java22 https://medium.com/graalvm/welcome-graalvm-for-jdk-22-8a48849f054c
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- 10. 10 JEP 456: UnnamedVariables & Patterns
- 11. 11 What is unnamedvariables?
- 12. 12 What is unnamedpatterns? Improve the readability by eliding unnecessary pattern components
- 13. 13 What is unnamedpatterns?
- 14. 14 JEP 457: Class-FileAPI (Preview)
- 15. 15 📁 Class-File API? ●Standard API for parsing, generating, and transforming Java class files ● Aim is to replace the bytecode manipulation framework ASM ● API that evolve together with the class-file format
- 16. 16 JEP 454: ForeignFunction & Memory API
- 17. 17 💾 Foreign Function &Memory API Replace JNI with a concise, readable, and pure-Java API Efficiently invoking foreign functions (i.e., code outside the JVM) Safely accessing foreign memory (i.e., memory not managed by the JVM) Wrap native libs in Java - Don’t rewrite them
- 18. 18 JEP 423: RegionPinning for G1
- 19. 19 JEP 447: Statementsbefore super(...) (Preview)
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- 22. 22 Allowed: Code before super(...)and this(...) That code before is called the “prologue” ● must not read any fields of the class ● must not call any non- static methods of the class. ● It must also not create instances of non-static inner classes
- 23. 23 JEP 459: StringTemplates (Second Preview)
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- 30. 30 🔎 More detailedview https://www.youtube.com/watch?v=dGo_QekdU5E&t=116s
- 31. 31 JEP 461: StreamGatherers (Preview)
- 32. 32 🔧 Stream API Intermediate operations Terminal operations E.g.map(...), filter(...), and limit(...) and more collect(Collectors.toMap(...)) count(), anyMatch(...) and more You could implement own terminal operation using Collector interface Custom intermediate operations?????
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- 34. 34 Gatherer interface Gatherer<T,A,R> T -the type of input elements A - the potentially mutable state type of the gatherer operation R - the type of output elements Supplier<A> initializer(); ● creation of a new, potentially mutable, state Integrator<A, T, R> integrator(); ● integrating a new input element to downstream BinaryOperator<A> combiner(); ● can be parallelized, merge partial result into one BiConsumer<A, Downstream<? super R>> finisher(); ● performing an optional final operation, when there are not more elements
- 35. 35 📽️ Let’s tryit out
- 36. 36 Stream API afterJDK22
- 37. 37 JEP 462: StructuredConcurrency (Second Preview)
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- 40. 40 JEP 464: ScopedValues (Second Preview)
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- 42. 42 🍪 Scoped Values:key-points preferred to ThreadLocal for virtual threads immutable data sharing bounded lifetime smaller footprint and complexity
- 43. 43 JEP 463: ImplicitlyDeclared Classes and Instance Main Methods (Second Preview)
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- 46. 46 JEP 458: LaunchMulti-File Source-Code Programs
- 47. 47 Simple java applaunch Since JDK11 we could execute .java source files directly, without an explicit compilation step $ java NewMainApp.java
- 48. 48 Multiple files javaapp launch $ java NewMainApp.java Because it’s JDK22
- 49. 49 Multiple files javaapp launch and some lib $ java --source 22 --enable-preview -cp "libs/*" NewMainApp.java
- 50. 50 JEP 460: VectorAPI (Seventh Incubator)
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- 52. 🍪 ListFormat class 53 MONDAY,TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, and SUNDAY
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- 54. 🌐 dev.java: Java22 is already there 55 https://dev.java/playground/
- 55. 🍿 Not netflixbut. Launch Stream 56 https://www.youtube.com/watch?v=AjjAZsnRXtE
- 56. 58 🔮 Java 23Predictions ● JEP 467: Markdown Documentation Comments ● JEP 466: Class-File API (Second Preview) ● JEP 465: String Templates ● JEP Draft 8325803: Flexible Constructor Bodies (Second Preview) ● JEP Draft 8326878: Vector API (Incubator) ● JEP Draft 8327844: Stream Gatherers (Second Preview) var nextLoc = new Point(2, 5); Point finalLoc = nextLoc with { x = 0; }; ● JEP 468: Derived Record Creation (Preview)
- 57. 59 OMilleR_98 oleh.melnyk.98 oleh- melnyk Demo That’sall :) Stay up to date!
- 58.
Editor's Notes
- #21 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #22 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #23 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #25 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #26 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #27 var language = "Java"; var coffeeJUG = "CoffeeJUG"; StringTemplate greetingTmpl = RAW."Hello \{language} community! Welcome to \{coffeeJUG} event!"; String interpolatedResult = greetingTmpl.interpolate(); System.out.println(interpolatedResult); // Hello Java community! Welcome to CoffeeJUG event! var fragments = greetingTmpl.fragments(); System.out.println(fragments); // [Hello , community! Welcome to , event!] var values = greetingTmpl.values(); System.out.println(values); // [Java, CoffeeJUG]
- #28 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #29 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #30 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #31 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #33 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #34 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #35 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #39 public Response handle() throws InterruptedException, ExecutionException { try (var executor = Executors.newVirtualThreadPerTaskExecutor()) { Future<User> task1 = executor.submit(() -> findUser); Future<Order> task2 = executor.submit(() -> findOrder); var userInfo = task1.get(); // join findUser var orderInfo = task2.get(); // join findOrder return new Response(userInfo, orderInfo); } } public Response handle() throws InterruptedException, ExecutionException { try (var scope = new StructuredTaskScope.ShutdownOnFailure()) { StructuredTaskScope.Subtask<User> task1 = scope.fork(() -> findUser); StructuredTaskScope.Subtask<Order> task2 = scope.fork(() -> findOrder); scope.join(); scope.throwIfFailed(); return new Response(task1.get(), task2.get()); } }
- #40 public Response handle() throws InterruptedException, ExecutionException { try (var executor = Executors.newVirtualThreadPerTaskExecutor()) { Future<User> task1 = executor.submit(() -> findUser); Future<Order> task2 = executor.submit(() -> findOrder); var userInfo = task1.get(); // join findUser var orderInfo = task2.get(); // join findOrder return new Response(userInfo, orderInfo); } }
- #42 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #43 var language = "Java"; var coffeeJUG = "CoffeeJUG"; // 1. Simple concatenation var greeting1 = "Hello " + language + " community! Welcome to " + coffeeJUG + " event!"; // 2. StringBuffer and StringBuilder var greeting2 = new StringBuilder() .append("Hello ").append(language) .append(" community! Welcome to ") .append(coffeeJUG).append(" event!") .toString(); // 3. String::format and String::formatted var greeting3 = "Hello %s community! Welcome to %s event!".formatted(language, coffeeJUG); // 4. java.text.MessageFormat var greeting4 = MessageFormat.format("Hello {0} community! Welcome to {1} event!", language, coffeeJUG);
- #52 List<String> weekdays = Arrays.stream(DayOfWeek.values()).map(Objects::toString).toList(); ListFormat listFormatter = ListFormat.getInstance(Locale.US, ListFormat.Type.STANDARD, ListFormat.Style.SHORT); System.out.println(listFormatter.format(weekdays));
- #54 List<String> weekdays = Arrays.stream(DayOfWeek.values()).map(Objects::toString).toList(); ListFormat listFormatter = ListFormat.getInstance(Locale.US, ListFormat.Type.STANDARD, ListFormat.Style.SHORT); System.out.println(listFormatter.format(weekdays));
- #55 List<String> weekdays = Arrays.stream(DayOfWeek.values()).map(Objects::toString).toList(); ListFormat listFormatter = ListFormat.getInstance(Locale.US, ListFormat.Type.STANDARD, ListFormat.Style.SHORT); System.out.println(listFormatter.format(weekdays));