What's New in Java 22

 

What's New in Java 22

Java 22, officially released in September 2024, brings several new features and improvements to the language. This release continues the trend of enhancing performance, developer productivity, and language expressiveness. Here's a look at some of the key features and changes in Java 22, along with examples to illustrate their usage.

1. Pattern Matching for switch Enhancements

Java 22 extends the pattern matching capabilities for switch expressions, making it even more powerful and versatile. You can now use pattern matching with records and sealed types, improving the readability and conciseness of your code.

Example:

java
public class PatternMatchingExample {
    public static void main(String[] args) {
        Object obj = new Rectangle(5, 10);

        String description = switch (obj) {
            case Circle(var radius) -> "A circle with radius: " + radius;
            case Rectangle(var width, var height) -> "A rectangle with width: " + width + " and height: " + height;
            case Shape s -> "A shape of type: " + s.getClass().getSimpleName();
            default -> "Unknown shape";
        };

        System.out.println(description);
    }
}

sealed interface Shape permits Circle, Rectangle {}

record Circle(int radius) implements Shape {}
record Rectangle(int width, int height) implements Shape {}

2. Record Patterns for Enhanced Deconstruction

Java 22 introduces record patterns for deconstructing records, which simplifies working with records and improves code readability.

Example:

java
public class RecordPatternsExample {
    public static void main(String[] args) {
        var point = new Point(10, 20);

        String description = switch (point) {
            case Point(int x, int y) when x == y -> "Point is on the diagonal: " + x;
            case Point(int x, int y) -> "Point is at: (" + x + ", " + y + ")";
            default -> "Unknown point";
        };

        System.out.println(description);
    }
}

record Point(int x, int y) {}

3. New Collection Factory Methods

Java 22 adds new factory methods to the Collections class, making it easier to create and initialize collections with default values.

Example:

java
import java.util.List;
import java.util.Map;
import java.util.Set;

public class CollectionFactoryMethodsExample {
    public static void main(String[] args) {
        List<String> names = List.of("Alice", "Bob", "Charlie");
        Map<String, Integer> ages = Map.of("Alice", 30, "Bob", 25);
        Set<String> fruits = Set.of("Apple", "Banana", "Cherry");

        System.out.println("Names: " + names);
        System.out.println("Ages: " + ages);
        System.out.println("Fruits: " + fruits);
    }
}

4. Improved JVM Performance with Native Method Inlining

Java 22 includes optimizations for the JVM, particularly in native method inlining. This improvement can lead to better performance for applications that rely heavily on native code.

Example:

This feature is mostly transparent to developers but can be seen in performance benchmarks where applications calling native methods show reduced latency.

5. Enhanced Language Support for Unicode

Java 22 introduces better support for Unicode 15.0, including new characters and symbols. This enhancement improves internationalization and makes it easier to work with diverse character sets.

Example:

java
public class UnicodeSupportExample {
    public static void main(String[] args) {
        String unicodeString = "Hello, Unicode! 🧩";
        System.out.println(unicodeString);
    }
}

6. JEP 431: Lightweight Concurrency

Java 22 introduces lightweight concurrency features, including virtual threads, which allow for more scalable and efficient handling of concurrent tasks.

Example:

java
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;

public class LightweightConcurrencyExample {
    public static void main(String[] args) {
        try (ExecutorService executor = Executors.newVirtualThreadExecutor()) {
            executor.submit(() -> System.out.println("Running on a virtual thread"));
        }
    }
}

Conclusion

Java 22 continues to evolve with features that enhance the language's power and usability. From improved pattern matching to better collection factory methods and native method inlining, these updates aim to make Java more efficient and developer-friendly. As always, updating to the latest version allows developers to leverage the newest advancements and improve their application's performance and maintainability.