Java in 2025: Overview of New Features and Changes

Java в 2025 году: что нового? Эволюция языка продолжается

В 2025 году язык программирования Java продолжает уверенно удерживать позиции одного из самых востребованных языков в корпоративной разработке, облачных технологиях и мобильной экосистеме Android. Благодаря шестимесячному релизному циклу, Java получает значительные обновления, которые делают его не только более производительным, но и удобным для разработчика. В этой статье мы разберём ключевые нововведения, которые появились в Java в 2025 году, и посмотрим, как они меняют повседневную практику программирования.

1. Virtual Threads (Project Loom) — now stable and faster

One of the most anticipated events was the final stabilization of Virtual Threads in the standard. In 2025, virtual threads ceased to be an experimental feature and became the recommended way to write concurrent code. The main advantage is the ability to create millions of threads without performance loss, which was previously impossible due to the overhead of system threads.

Here is a typical example of using a virtual thread in Java 2025:

import java.util.concurrent.Executors;import java.util.stream.IntStream;

public class VirtualThreadsExample {    public static void main(String[] args) {        try (var executor = Executors.newVirtualThreadPerTaskExecutor()) {            IntStream.range(0, 10_000).forEach(i -> executor.submit(() -> {                System.out.println("Task " + i + " is running in " + Thread.currentThread());                try { Thread.sleep(100); } catch (InterruptedException e) { }            }));        }        System.out.println("All virtual threads have completed.");    }}

Thanks to this innovation, server applications in Java have become significantly easier to scale, while the code remains simple and readable. Developers no longer need to use complex frameworks for reactive programming — virtual threads solve the blocking problem at the platform level.

2. Pattern Matching and enhanced switch expressions

In 2025, Pattern Matching in Java has reached maturity. It now works not only with instanceof, but also with records and serialized data. This allows for writing more concise and safe code.

Example of using Pattern Matching with records:

sealed interface Shape permits Circle, Rectangle {}record Circle(double radius) implements Shape {}record Rectangle(double width, double height) implements Shape {}

public double calculateArea(Shape shape) {    return switch (shape) {        case Circle c -> Math.PI * c.radius() * c.radius();        case Rectangle r -> r.width() * r.height();        default -> throw new IllegalArgumentException("Unknown shape");    };}

Additionally, Java 2025 introduced support for Pattern Matching for arrays and collections, simplifying work with complex data structures. Now you can decompose lists directly in a switch condition:

List<String> items = List.of("a", "b", "c");switch (items) {    case List<String> l when l.size() == 3 -> System.out.println("Three elements");    case List<String> l -> System.out.println("Different quantity");}

3. Improved generics and support for primitive types

A long-awaited innovation is the extension of the generics system to work with primitive types. In 2025, Java allows using int, double, boolean, and other primitives as parameters of generic classes without autoboxing. This significantly improves performance in computational tasks and reduces the load on the garbage collector.

Example:

// Previously impossible: List<int> — compilation error// Now in Java 2025: