The Java Development Kit (JDK) 25, set to arrive in September, has already proposed its first feature: a stable values API that aims to significantly improve the startup of Java applications. This innovative API promises to break up the monolithic initialization of application state, leading to faster and more efficient application startup times.

Stable values, objects that hold immutable data, are treated as constants by the Java Virtual Machine (JVM). This allows for the same performance optimizations that are enabled by declaring a field final. Moreover, stable values offer greater flexibility in terms of the timing of initialization, making them an attractive solution for improving application startup.

The stable values API is expected to bring several benefits to Java developers. In addition to boosting application startup, it will decouple the creation of stable values from their initialization without incurring significant performance penalties. Furthermore, it will guarantee that stable values are initialized at most once, and enable user code to enjoy constant-folding optimizations previously available only to JDK-internal code.

It's worth noting that JDK 25 will be the first long-term support release of standard Java since JDK 21, which arrived in September 2023. Long-term support releases receive multiple years of support, making JDK 25 a significant milestone in the Java ecosystem.

Before JDK 25, Oracle plans to release JDK 24 on March 18, which will feature several previewed functionalities, including a key derivation functions API, scoped values, structured concurrency, and flexible constructor bodies. Some of these features may also make it into JDK 25, further enhancing the capabilities of the Java platform.

The proposal of the stable values API in JDK 25 marks a significant step forward in improving the performance and efficiency of Java applications. As the Java ecosystem continues to evolve, developers can expect to see further innovations and enhancements that will shape the future of Java development.

With the release of JDK 25, Java developers can look forward to improved application startup times, enhanced performance, and increased flexibility in their coding endeavors. As the Java community continues to grow and adapt, it will be exciting to see how this new API is utilized and the impact it will have on the industry.