Evolution of Java language v1–v25: key features

Sealed Classes

// Parent class
public sealed class Shape permits Circle, Rectangle { }

// Allowed subclasses
public final class Circle extends Shape { }
public final class Rectangle extends Shape { }

Text Blocks

String json = """
    {
        "name": "Alice",
        "age": 30
    }
    """;
System.out.println(json)

Scoped Values

try (var scope = ScopedValue.where("user", "Alice")) {
    new Thread(() -> {
        System.out.println(ScopedValue.get("user")); // Alice — inherited
    }).start();
} // scope closes, value disappears

Record Pattern

Object obj = new PersonRecord("Alice", 30);

if (obj instanceof PersonRecord(String name, int age)) {
    System.out.println(name + " " + age); // unpacked immediately
}

Pattern Matching for switch

switch (obj) {
    case PersonRecord(String n, int a) when a >= 18 -> System.out.println(n + " is adult");
    case PersonRecord(String n, int a) -> System.out.println(n + " is minor");
    default -> System.out.println("Unknown");
}

Project Panama

import java.foreign.*;

CLinker linker = CLinker.systemCLinker();
Symbol lookup = linker.lookup("printf");
//You can directly call printf from C without JNI templates.
// supported C, C++, Rust, Fortran, Assembler (via C ABI)

Test - Check your knowledge about which version of Java introduced key features and changes.