As Java developers, we constantly balance the trade-offs associated with making our fields final! On one hand, final instance fields are a requirement in order to make our classes immutable, which helps promote cleaner and more robust code. In addition, the JVM compilers, javac and JIT, will consider certain final fields when making constant fold optimizations which eliminate unnecessary computation from our compiled code by simplifying/computing constant expressions ahead of time. However, there's a major limitation to using final fields. We must initialize a final field immediately. This is problematic if the field is expensive to create.

Baeldung offers insights into Java development, Spring framework, and software architecture, providing tutorials, articles, and best practices for mastering Java programming language and its ecosystem. By exploring Baeldung's curated content, developers can learn about Spring Boot, Hibernate, RESTful APIs, and microservices architecture for building robust and scalable Java applications. Whether you're a Java beginner or an experienced developer, Baeldung offers resources to deepen your understanding of Java development and stay updated with industry best practices.

Baeldung

Java 25 introduces the Stable Value API (JEP 502) to solve the trade-off between immutability and delayed initialization. StableValue acts as a thread-safe wrapper that guarantees single initialization while enabling deferred computation of expensive objects. The API includes StableSupplier for lazy initialization, StableList and StableMap for collections with on-demand element computation, and StableFunction for memoized function calls. This approach maintains immutability benefits and JVM optimization opportunities while avoiding upfront initialization costs that can slow application startup.

Stable Values in Java 25