Coursera Flash Sale
40% Off Coursera Plus for 3 Months!
Grab it
Explore the evolution of Java's `final` keyword and its limitations in achieving true immutability in this conference talk from the 2025 JVM Language Summit. Discover why the common advice to "prefer immutability" faces practical challenges when using `final` fields, including their vulnerability to reassignment through constructors or reflection, and their inflexible initialization requirements that must occur eagerly during construction or class initialization. Learn about the gaps in compiler and bytecode protection that undermine the integrity of Java applications and prevent important performance optimizations like constant-folding. Examine the steps being taken to address these limitations, including Stable Values (Preview) and the "Prepare to Make Final Mean Final" JEP draft, which aim to enable Java to better leverage immutable data structures. Understand how these improvements could reduce application startup burden by allowing more flexible initialization timing while maintaining true immutability guarantees. Gain insights into the technical challenges of object initialization and the proposed solutions that will strengthen Java's immutability model for safer concurrent programming and enhanced performance optimization opportunities.
