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Java 24 Experimental Features: Three Key Innovations

Java 24, released on March 18, 2025, introduces several experimental features that represent significant advancements in JVM technology. Among the 24 Java Enhancement Proposals (JEPs) included in this release, two are designated as experimental features. Here are the three most interesting experimental innovations in Java 24. 1. Compact Object Headers (JEP 450) The Compact Object Headers feature represents a fundamental optimization in memory management for the HotSpot JVM . This experimental feature reduces the size of object headers from between 96 and 128 bits down to 64 bits on 64-bit architectures. Technical Impact The implementation demonstrates measurable benefits in real-world applications. Early adopters of Project Lilliput , which inspired this feature, report that live data is typically reduced by 10-20%. This reduction translates directly into improved heap utilization, better deployment density, and increased data locality. Activation and Usage Since this is an experimenta...
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Java 24 Release - March 2025

Java 24 Release - March 2025 Oracle released Java 24 on March 18, 2025, as the latest version of the Java SE Platform. This release represents the Reference Implementation of Java SE Platform version 24 as specified by JSR 399 in the Java Community Process. Key Features: Stream Gatherers : A new enhancement that gives developers fine-grained control over how elements are grouped and processed within streams, making complex data transformations more expressive and efficient The final feature set includes 24 JEPs (Java Enhancement Proposals), with two being Generational Shen ( Java 24 New Experimental features ) Enhancements to the platform's performance, stability, and security to help organizations accelerate their business growth ( Oracle Releases Java 24 ) Java Release Schedule Updates - Java 25 LTS Oracle has confirmed that Java SE 8, 11, 17 and 21 are LTS (Long Term Support) releases, with Oracle intending to make future LTS releases every two years, meaning the next planned ...
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Did you know that methods in Java have a size limit?

The JVM's method size limit of 64kB of bytecode is an important constraint for Java developers to understand. Here's more information about this limitation: JVM Method Size Limit The 65,535 (64K-1) byte limit on method bytecode is a fundamental constraint in the Java Virtual Machine (JVM) specification. This isn't about the number of lines of source code, but rather the compiled bytecode size of a single method. Why This Limit Exists This limit results from the JVM's internal design, specifically - how Java represents method code. The JVM uses a 16-bit unsigned index (u2) in the class file format to represent code length (2^16 = 65 536), but since indexing starts at 0, the maximum size is 65,535 bytes Common Causes of Large Methods Methods can grow unexpectedly large in bytecode due to, eg. complex logic with many branches and conditions. Methods can grow due to large switch statements, inlined code (especially from lambdas), string concatenation operations. Method refe...
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Customizable HTML tag: select/option

Ó, HTML bože, wwwládca webapp neba, vďaka! Na toto som čakal roky (desiatky rokov).  Kto pracuje s web technológiami, kde sa používa HTML, isto neraz zaklial, keď musel použiť klasický, hmm, nazvyme ho ”combobox”. HTML tag <select> s jeho položkami <option> je štýlovateľný asi tak, ako chcieť urobiť z trabanta mercedes. O jeho funkcionalite ani nehovoriac. Preto bolo vždy potrebné použiť nejaký komponent (JS). Ale tomu je teraz koniec. Je to tu! Tag <select> má veľmi blízko k takmer dokonalosti. Síce to ešte trochu potrvá (aktuálne v Stage 2/ WHATWG https://developer.chrome.com/blog/rfc-customizable-select ), ale verzia na vyskúšanie je už na ceste k vám. Vyskúšajte si to Ak máte minimálne Chrome Canary 130, cez chrome://flags si zapnite príznak #experimental-web-platform-features a môžete sa pohrať s Codepen ukážkami https://codepen.io/collection/BNZjPe alebo skúsiť nakódovať niečo vlastné. Nové tagy/selectory V rámci CSS teraz viete „masírovať” vzhľad celého ...
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My, ľudia, sme veľmi namyslení.

Myslíme si, že sme ktovieako inteligentní. Nedokážeme jednoducho a rýchlo zrátať z hlavy ani dve trojciferné čísla. Nerozoznáme margarétku od sedmokrásky. Nevieme sa dohovoriť s človekom hovoriacim iným jazykom, dokonca niekedy ani cez plot s vlastným susedom. AI väčšinu z toho dnes zvláda ľavou zadnou (ak by ju mala) a dosiahla to iba za niekoľko rokov. Stačilo len trochu viac výpočtového výkonu. Pamätám si na feike predmet Základy umelej inteligencie, kedy bol tento vtedy vedný odbor ešte len v plienkach, no bola to jedna z mála prednášok, na ktorú sme sa (radi) prinútili ráno vstať. A kde sa v IT nachádzame teraz? Weby a apky štátu a samospráv sú nepoužiteľné. Povyšujeme dizajn nad funkciou. Každý softvér má v viac bugov ako riadkov kódu. Takmer každý týždeň vznikne nový model AI a ona sa pri tom všetkom učí na našich vedomostiach a chybách - a aj s našimi chybami. Už nás začala prevýšovať aj v kreatívnom, abstraktnom myslení, údajne aj v empatii a emočnej inteligencii. No nezabúdaj...
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What is the minimum app in Java (21)?

Who doesn't know "Hello, World!"? When you start writing a code in a new language, you usually write this simple program. What does it look like in Java code? class App { public static void main(String[] args) { System.out.println("Hello, World!"); } } But, explain to a beginner what "public static void" and strange args are. What would you say if the program could be simplified. class App { void main() { System.out.println("Hello, World!"); } } Let's make it even simpler, without class declaration. void main() { System.out.println("Hello, World!"); } Yes, this is simplest Java code in Java 21 release. Try it yourself. In a Java 21 preview feature (JEP 445) it needs to be enabled by with the --enable-preview flag. Just compile your application by command javac --release 21 --enable-preview App.java and run it as simple as java --enable-preview App This simplification i...
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