Java 25 Launches Stable Values API for Enhanced Immutability

JEP 502 introduces the Stable Values API in JDK 25, enhancing application startup performance through deferred immutability. This feature allows for thread-safe, at-most-once initialization of complex objects, optimizing performance without the traditional pitfalls of eager initialization. The new API aims to combine the performance benefits of final fields with the flexibility of lazy initialization.

The Stable Values API specifically targets application startup performance issues. Unlike final fields, which must be initialized during construction or class initialization, stable values can be initialized on-demand, enabling JVM constant-folding optimizations typically reserved for final fields. For more details, refer to the Stable Values Preview.

The API primarily uses the StableValue class, which holds a single data value that can be set exactly once through the method orElseSet(). Here’s an example of its implementation:

class OrderController {
    private final StableValue<Logger> logger = StableValue.of();
    
    Logger getLogger() {
        return logger.orElseSet(() -> Logger.create(OrderController.class));
    }
}

This eliminates the common issues associated with traditional lazy initialization patterns, making the initialization thread-safe and efficient. The API extends to include stable suppliers and stable lists, allowing for more sophisticated data management strategies.

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Key Features of JDK 25

Instance Main Methods and Compact Source Files

JEP 512 introduces Compact Source Files and Instance Main Methods, simplifying the Java programming experience for beginners by allowing streamlined syntax and automatic imports for core libraries. For instance, developers can write simpler programs without explicit class declarations. Here’s an example:

void main() {
    IO.println("Hello, World!");
}

This enhancement allows the launcher to search for an instance main method if a suitable static main method isn’t available, greatly simplifying the entry point for novice developers.

For enhanced console I/O operations, JEP 512 introduces java.lang.IO, which allows basic interactions without requiring explicit imports.

Flexible Constructor Bodies

Flexible constructor bodies in JDK 25 enable developers to include statements before calling super(...) or this(...). This flexibility improves safety and initialization processes, allowing fields to be initialized before being used by other methods.

Module Import Declarations

JEP 511 introduces module import declarations, allowing succinct importing of all packages exported by a module. This simplifies the use of modular libraries and improves code organization by reducing the complexity of managing extensive import statements.

Performance Improvements for Strings

JDK 25 enhances the performance of the String class, improving the speed of String::hashCode. This change optimizes operations involving string lookups, particularly when using strings as keys in immutable maps.

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Java continues to evolve, with features aimed at enhancing the programming experience. The upcoming JDK 25 introduces improvements to the Foreign Function and Memory API, structured concurrency, and more. As Java heads into its fourth decade, the language remains a foundational tool for enterprises, supported by a vibrant community and a robust ecosystem.

For businesses seeking reliable authentication solutions, mojoauth offers comprehensive CIAM solutions, allowing for effective management of user identities and access.

Explore our services or contact us at mojoauth to learn more about how we can help you enhance your authentication processes.

*** This is a Security Bloggers Network syndicated blog from MojoAuth – Go Passwordless authored by Govardhan Sisodia. Read the original post at: https://mojoauth.com/blog/java-25-launches-stable-values-api-for-enhanced-immutability/