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LazyConstants in JDK 26 (Page last updated February 2026, Added 2026-02-26, Author Nicolai Parlog, Publisher Inside Java Newscast). Tips:

• final LazyConstant<T> myfield; myfield = LazyConstant.of(T::initialize); ... later ... myfield.get().
• Only the first call to LazyConstant.get() does any work (if successful). It handles concurrency and every subsequent call just returns the constant - and the implementation is designed for the JVM to be able to easily optimize the access.
• Use LazyConstant.of(Supplier<T>) to define the computation and LazyConstant.get() to retrieve the value.
• LazyConstant leverages the @stable annotation, which informs the Java runtime that the field will not be reassigned, enabling constant folding optimizations. Unlike standard final instance fields, which can sometimes be changed via reflection, LazyConstant values are treated as truly constant by the JVM.
• If LazyConstant.get() throws an exception, the supplier for the get() will be retried on subsequent calls. Circular dependencies will throw an IllegalStateException to prevent infinite loops.
• Lazy collections are supported, specifically List.ofLazy and Map.ofLazy, which compute individual elements or values only when first accessed. These lazy collections are unmodifiable, thread-safe, and support constant-folding optimizations.

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